JADEER Learning Manual - Electrical Area 1 PDF

Classification: General Business Use JADEER LEARNING MANUAL ELECTRICAL AREA 1  0 255 4 227 77 217 247...

Classification: General Business Use JADEER LEARNING MANUAL ELECTRICAL AREA 1  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CONTROL PAGE DISCIPLINE JOB / AREA # DESCRIPTION ASSIGNMENT Electrical Technician Area 1 Basic Plant Electrical & Safety DOCUMENT REFERENCE # CONTROLS JAD-LC -A1-YP-EMT-LM MODULE # REVISION # ISSUE DATE: NEXT REVIEW DATE: 2024 2024.01 05 Nov 2024 01 Oct 2027 DEVELOPED BY: REVIEWED BY APPROVED BY: (SUBJECT MATTER EXPERTS): (SUBJECT MATTER EXPERTS): (AREA OWNERS/LEADERS): Marwan Owaidhah (12943) Electrical Ali Fallatah (12610) Electrical Specialist Bandar Al-Mesawi (13107) Electrical Trainer Specialist Ahmed Haresi (33423) Electrical Specialist Page | 2  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 UEC/PSU LAYOUT AND FUNCTIONAL LOCATION Page | 3  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Table of contents SN SUBJECT PAGE NUMBER 1 Introduction 6 2 Function of the P.S.U. 6 3 Layout of the P.S.U. 6 4 Location of the P.S.U. 7 Page | 4  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Objectives SN Objectives 1 To understand YANPET Electrical Substation Page | 5  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 PSU Layout & Functional Location Introduction. The primary scope of this Booklet is to provide the reader with a brief knowledge of the functions, layouts & overall location within YANPET complex for the PSU. 1. Function of the P.S.U. P.S.U Power Supply Unit, sometimes referred to as U.E.C (Unitized Electrical Center) is an electrical building within each operating unit. It receives the electrical power supply both normal (provided by the utility company) and essential (provided by the essential generators) from the main 34.5KV Sub- station and step it down to the required voltage levels to serve the designated operating unit equipment providing protection & control functions. The term U.E.C is commonly used in YPT old section of the complex, while the P.S.U is mostly known at YEP. 2. Layout of the P.S.U. The PSU/UEC's consist of two major items: 2.1. Transformers Yard. It houses all transformers required for the unit electrical needs with the exception of lighting transformers which are located adjacent to their service areas. Two or more sets of normal power cables transfer the power supply from the 34.5 KV Sub-station to be terminated at the power transformers as in YPT. In YEP, those power cables are terminated at an SF6 Switches which further distributed the power supply to every power transformer in the yard. The essential powers are being transferred via one set of power cables at 5kv level to an essential transformer in the yard. 2.2. Air-Conditioned Building. It is typically it consists of: Page | 6  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 2.2.1. The MV Switchgear/MCC lineup will be metal clad type with draw out circuit breaker assembly, complete with all required buses, protective and metering devices, wiring, etc. It is furnished with two main incomers, one bus tie coupler, and the required number of circuit breakers and MV starters (Contactors), including totally furnished spare and space units (as per the “Utility Unit Load List”). It is designed to operate as “Secondary Selective” system with two normally closed incomers and one normally open bus tie coupler, with both associated transformers sized to feed the full load in case one of the transformer units is ruled “out of service”. It has future expansions with minimum possible disturbances and shall be provided with all required safety and interlocking devices. 2.2.2. The Low Voltage Switchgear/MCC line-ups is metal enclosed type, NEMA 1, free standing, and completely designed and furnished to feed the process unit. It operates as “Secondary Selective” system and consist of two normally closed incomers and one normally open bus tie coupler, with both associated transformer sized to feed the full load in case one of the transformer units is ruled “out of service”. 2.2.3. The emergency MCC line-up is consist of a free standing, NEMA 1, metal enclosed assembly, furnished with Feeder Breakers and/or Motor Starters as required to feed the substation emergency loads such as the alternate feeders for Battery Chargers & UPS units, air conditioning units, emergency indoor and outdoor lighting, lube oil motors etc. 2.2.4. DC Supply System consists of Lead Acid Battery Bank charged with one battery charger as in YPT or two chargers as in YEP. The DC system is to provide continuous power to the switchgears control circuit & associated protective relays for optimum reliable operation. 3. Location of the P.S.U The P.S.U/U.E.C's is generally located at the edge of batter limit of the unit or at the nearest location to the serviced equipment depending on the design. They are all located in none-classified areas. The numbers of U.E.C's per plant is dependent on the size of the plant. Page | 7  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 3.1. U.E.C's List & Location in YPT. Number Operation Unit Location UEC-1001 Ethylene U10 UEC-1002 Ethylene U10 UEC-2001 Ethylene-Glycol U20 UEC-3001 Polyethylene U30 UEC-3002 Polyethylene U30 UEC-3003 Polyethylene U30 DP UEC-3004 Polyethylene U30 UEC-5001 Offsite U50 UEC-6001 Utilities U60 UEC-6401 Offsite U64 UEC-6503 Offsite U19 UEC-6513 Offsite U82 UEC-7401 Offsite U74 UEC-7901 Offsite U79 Page | 8  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 3.2. Typical YPT U.E.C's Plan View & Power Distribution. FIGURE 3.1.2 UNIT 10 ETHYLENE EAST UEC PSU-1002 Page | 9  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 FIGURE 3.1.4 UNIT 10 ETHYLENE SIMPLIFIED ONE LINE DIAGRAM Page | 10  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 3.3. P.S.U.'s Location in YEP. Number Location Operation Unit 2PSU-1001 Ethylene U210 2PSU-1002 Ethylene U10 2PSU-2001 Ethylene-Glycol U20 2PSU-3001 Polyethylene U30 2PSU3601 Polyethylene U30 2PSU-4001 Polyethylene U30 2PSU-6502 Utilities U260 2PSU-6503 Offsite Offsite 2PSU-6514 Offsite Offsite 2PSU-6515 Offsite Offsite Page | 11  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 2PSU-1001 Plan View Page | 12  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Unit 210 Ethylene Unit Simplified One Line Diagram Page | 13  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Knowledge review 1. A PSU / UEC is an enclosure maintained at a a. Positive pressure. b. Negative pressure. c. Outside pressure. d. None of the above. 2. Application of Battery banks at UEC is a. Instrument DC control power. b. Switchgear DC control power. c. Emergency light power. d. None of the above. 3. Location of individual unit UEC/PSU’s are normally a. At the middle of the Unit. b. Immediately after the battery limit of the unit. c. Centralized at one location. d. None of the above. 4. Each UEC/PSU has got a monitoring system known as a. Annunciator alarm system. b. Plant alarm system. c. Emergency alarm system. d. None of the above. Page | 14  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 True or false 1. YANPET -1 has got 4 main sub stations. a. True b. False 2. YANPET – 2 has got 2 main substations. a. True b. False 3. When an annunciator alarm is reported at a UEC/PSU you should immediately reset it. a. True b. False 4. In an UEC/PSU annunciator panel reset is possible only after acknowledged. a. True b. False Page | 15  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SIH/RIE LAYOUT AND FUNCTIONAL LOCATION Page | 16  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Table of content SN SUBJECT PAGE NUMBER 1 Introduction 17 2 Design & Function of the SIH/RIE’s 17 3 System Power Supplies 17 4 DC Power Supplies 18 5 Utility Power 18 6 Grounding and Lighting Protection 18 7 Typical Power Distribution Drawings 19 Page | 17  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Objectives SN Objectives 1 To understand YANPET RIE/SIH installation Page | 18  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SIH/RIE’s Layout & Functional Location Introduction The primary scope of this Booklet is to provide the reader with a brief knowledge of the functions, layouts & overall location within YANPET complex for the RIE/SIH’s. 1. Design & Function of the SIH/RIE’s The SIH (Seattleite Instrument House) as it known in YPT/RIE's (Remote Instrument Enclosure) YEP terminology, are prefabricated and self-contained buildings –mounted transportable enclosures of industrial noncombustible construction, completely assembled, wired and tested at the factory. The base, frame, and crossbeams that support the floor and equipment shall be constructed of structural steel. Two doors were provided on each RIE/SIH. A computer-type floor consisting of steel plates finished with skid proof paint shall be provided. The enclosure wiring space under the floor is about of twenty inches (20") deep. External cables are entered through field cut holes in the base floor. The walls and roof are of insulated panel construction. The SIH/ RIE’s are housing instrumentation and control equipment whose functional operation will be essential in controlling and securing an orderly shutdown of the plant. All signal measurement between the field equipment/ instrumentations and the control room goes through the SIH/RIE’s. 2. System Power Supplies 2.1. Dual power supplies: Each system located within the RIE (DCS, PLC, and TMR PLC) is provided with dual power supplies unless specifically noted otherwise. 2.2. Two UPS’s are provided in accordance with specification of the RIE. For the SIH’s one UPS was provided along with a DC-DC Converter. 2.3. A distribution board is provided for each of the two UPS’s (UPS/DC-DC). These distribution boards, in addition to providing the supplies within the RIE/SIH’s, is also providing supplies for the field loads e.g., compressor panels etc. 2.4. Supply source: Each of the systems dual supplies shall is fed from a separate 115-volt (UPS /DC-DC Converter) distribution board. 2.5. The Fire and Gas system have a single power supply. Page | 19  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 3. DC Power Supplies 3.1. It is anticipated that the DCS, TMR PLC’s and PLC’s require separate power supplies for all 125 volt DC and 24 volt DC loads. 3.2. Dual DC supplies are provided for each system requiring power for these loads. These are wired in a redundant configuration such that if any supply fails the load will continue to be supplied by the other power supply. 3.3. Each DC supply is fed from a separate UPS. 3.4. The DC power supply feeds shall be provided with properly coordinated protection such that a fault in any field load is cleared by the protection for that load without affecting any other. Similarly, the fault to the supply of any branch circuit shall be cleared by the protection for that branch without affecting any other branch. 3.5. The DC power supplies are grounded. 4. Utility Power 4.1. A transformer is provided for utility power. The supply for this may be taken from either of the 480-volt distribution panels. 4.2. A distribution board is provided for all lighting and convenience socket outlets. 5. Grounding and Lighting Protection 5.1. Two clearly marked separate copper ground busses are to be provided which shall be run throughout the RIE. These are: 5.1.1. Signal Ground The instrument signal ground shall be mounted separately from the safety ground bus and shall be insulated from the RIE. All signal references and cable screens including incoming field cable screens shall be connected to this bus. 5.1.2. Safety Ground The safety ground shall be mounted on and connected to the base frame. This shall be used for all safety grounding and all steelwork and cabinet metal work shall be connected to this earth bus. Page | 20  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 6. Typical Power Distribution Drawings TYPICAL 480V DISTRIBUTION FOR RIE’S SEE UPS ONE LINE DRAWING 60-EP-108 Page | 21  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 FIGURE 2.18.5E.3 UNIT 60 SIH 60-1 UPS SYSTEM Page | 22  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 FIGURE 2.18.6A 24V DC POWER IN SIH's Page | 23  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Figure 2.18.7.1 Unit 10 (125VDC) System ONE LINE DIAGRAM Page | 24  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Knowledge review 1. SIH/RIE’s are equipped with: a. GUS stations b. PLC & UPS c. Field Instruments d. None of the above 2. How many source of power supply does SIH/RIE - PLC’s have a. One b. Two c. Three d. None of the above 3. How many isolated & dedicated ground bars does SIH/RIE - have. a. One b. Two c. Three d. None of the above State True or False: 1. Radio can be used freely at a SIH/RIE. a. True b. False Page | 25  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 2. SIH/RIE’s are an interface location between plant instruments & control room. a. True b. False Page | 26  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 HAND AND POWER TOOLS Page | 27  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 TABLE OF CONTENTS SN SUBJECT PAGE NUMBER 1 Learning Objectives 25 2 Definitions 26 3 Basic Safety Rules for Tools 28 4 Best Practices and General Safety Rules 30 5 Basic Manual Hand Tools Best Practices 32 6 Basic Power Hand Tools Best Practices 34 Page | 28  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 OBJECTIVES SN OBJECTIVE 1 Basic understanding of Hand and Power Tools & their Use in Industry. Page | 29  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 BASIC TOOLS INTRODUCTION HAND AND POWER TOOL SAFETY Hand and power tools are a common part of our everyday lives and are present in nearly every industry. These tools help us to easily perform tasks that otherwise would be difficult or impossible. However, these simple tools can be hazardous and have the potential for causing severe injuries when used or maintained improperly. Special attention toward hand and power tool safety is necessary in order to reduce or eliminate these hazards. In the process of removing or avoiding the hazards, workers must learn to recognize the hazards associated with the different types of tools and the safety precautions necessary to prevent those hazards. Hand Tools Power Tools Page | 30  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 DEFINITIONS Hand tools are non-powered “no energy sources”. They include anything from axes to wrenches. “The greatest hazards posed by hand tools result from misuse and improper maintenance.” Power tools uses energy source to operate. There are several types of power tools, based on the power source they use: ✓ Electric, ✓ Pneumatic, ✓ Liquid Fuel, ✓ Hydraulic, and ✓ Powder-actuated. Page | 31  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 BASIC SAFETY RULES FOR TOOLS Five Basic Safety Rules for Tools “OVERVIEW” Always wear Personal Protective Equipment (PPE): e.g., goggles, face shield, hearing protection, etc. and remember, you are the most important part of safety rules. The tool may be efficient, essential, time-saving or even convenient; but it is also dangerous. When using any hand tool you must use it correctly, following the methods prescribed in this manual. Select the Right Tool for the Job: Examples of unsafe practices are: Striking hardened faces of hand tools together (such as using a carpenter's hammer to strike another hammer, hatchet, or metal chisel), using a file for a pry, a wrench for a hammer, using a ‘cheater’, and pliers instead of the proper wrench. Keep Tools in Good Working Condition: Wrenches with cracked work jaws, screw drivers with broken points or broken handles, hammers with loose heads, dull saws, and extension cords or electric tools with broken plugs, improper or removed grounding prongs, or split insulation are examples of tools in poor conditions. Tools that have deteriorated in this manner must be taken out of service. Page | 32  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Page | 33  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 HAND TOOLS: BEST PRACTICES AND GENERAL SAFETY RULES Use tools that are the RIGHT SIZE & RIGHT TYPE for your job. DON’T work with OILY or GREASY hands. Do not carry a sharp tool in your pocket. Don’t use damaged tools such as loose, cracked etc... Don’t FORCE screws; make sure that the correct screw for the job is being used. Do not cut towards yourself when using cutting tools. Do not use tools for jobs for which they are not intended. For example, do not use a slot screwdriver as a chisel, pry bar, wedge or punch, or wrenches as hammers. Don’t try to increase your leverage by using a “cheater” with a wrench. Wrenches are designed at the right strength for their size and length “Do not apply excessive force or pressure on tools”. Do not throw tools. Hand them, handle first, directly to other workers. Do not carry tools in a way that interferes with using both hands on a ladder, while climbing on a structure, or when doing any hazardous work. If working on a ladder or scaffold, tools should be raised and lowered using a bucket and hand line. Page | 34  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 HAND TOOLS: BEST PRACTICES AND GENERAL SAFETY RULES Do not use a knife as a screwdriver. The blade can snap and injure an eye. Never carry a screwdriver or chisel in your pocket. If you fall, the tool could cause a serious injury. Instead, use a tool belt holder. Replace loose, splintered, or cracked handles. Loose hammer, axe, or maul heads can fly off defective handles. Use the proper wrench to tighten or loosen nuts. Pliers can chew the corners off a nut. When using a chisel, always chip or cut away from you. Use a soft-headed hammer or mallet to strike a wooden chisel handle. A metal hammer or mallet may cause the handle to split. Do not leave tools lying around on elevated structures, such as a platform or scaffold, as they may be bumped and fall. Take the time necessary to clarify yourself with the safety guidelines for each tool in manual. You must also be alert for any conditions that might endanger yourself or fellow workers. Page | 35  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 POWER TOOLS: BEST PRACTICES AND GENERAL SAFETY RULES: Before using any power tool, it’s important to read and follow all safety precautions found in the owner’s manual for the tool for safe power tool use. Do not use tools during electrical work unless they are designed for electrical work (e.g., properly insulated). Inspect all portable power tools before using them. See that they are clean and in good condition. Never operate any power equipment unless you are completely familiar with its controls and features. Before connecting a power tool to a power source, be sure the tool switch is in the “OFF” position. Never try to clear a jammed power tool until it is disconnected from the power source. After using a power tool, turn off the power. Never leaf the site while the tools connected to the power. Never carry a tool by the cord or hose. Never yank the cord or hose to disconnect it from the receptacle. Keep cords and hoses away from heat, oil and sharp edges. Avoid accidental starting. Do not hold fingers on the switch button while carrying a plugged-in tool. Maintain tools with care; keep them sharp and clean for best performance. Follow instructions in the user’s manual for lubricating and changing accessories. Page | 36  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Be sure to keep good footing and maintain good balance when operating power tools. Remove all damaged portable electric tools from use and tag them: "Do Not Use.". Use Ground Fault Circuit Interrupter (GFCI) protected circuits to operate all portable power tools. When working around machinery, do not wear loose clothing, torn sleeves, ties, key chains, rings, watches, or any item that could become entangled in the machinery. Contain long hair when working around machinery. Make sure all guards are in place and in proper working condition. Page | 37  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 TOOLBOXES: Toolboxes are used for storing tools. They are usually made of steel but sometimes of wood or plastic. Portable toolboxes are used for carrying and storing a variety of hand tools. Both special and common tools, such as mechanic’s, electrician, and carpentry tools can be found in toolboxes. Chest-type toolboxes generally contain larger tools, such as specialized automotive tools or machinist’s tools, requiring a more permanent location. Page | 38  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 FLAT STEEL RULE: It is the simplest measuring tool and it is used for measuring where accuracy is not an extremely critical factor. Steel rules can be rigid or flexible, thin or wide. It is easier and more accurate to use a thin rule, since it is closer to the work being measured. Page | 39  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 MEASURING TAPES: A measuring tape can come in any length from 6 to 50 feet. The most common are 10, 16, and 25 feet. Shorter tapes usually have a curved cross section so they roll easily but stay rigid when extended. Longer tapes are usually flat and should be laid along a surface to avoid sagging in the middle. Page | 40  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 LEVEL: Tools designed to prove whether a plane or surface is in the true vertical or true horizontal. All levels consist of a liquid- filled glass tube or tubes supported in a frame. There are many types of water level such as master precision level carpenter’s level, line level & torpedo level. Page | 41  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 THICKNESS (FEELER) GAGES: Feller gages are using to checking and measuring of small openings such as contact points, narrow slots, and so forth. They are widely used to check the flatness of parts in straightening and grinding operations and in squaring objects with a try square. Page | 42  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 MAGNETIC BASE INDICATOR HOLDER: It is a one-piece metal assembly that attaches to the work surface magnetically. A gage or indicator attaches to the assembly. Base indicator holders are used for attaching gages to lathes, milling machines, shapers, or any machine where graduations are difficult to read. Magnetic base indicator holders are available in many sizes and designs depending on application. Page | 43  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 PLIERS: Pliers are a special type of adjustable wrench that are scissor-shaped tools with jaws. The jaws usually have teeth to help grip objects and are adjustable because the two handles move on a pivot. Pliers are made of hardened steel and come with different head styles that determine their use. Pliers are used to hold, cut, and bend wire. Page | 44  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 VISE GRIP: A vise grip is a type of locking pliers. One side of the handle has an adjusting screw used to set the size of the jaws. Some models also include a lever on the opposite side of the bolt to unlock the pliers by pushing the handles apart. TONGUE AND GROOVE PLIERS: Also known as channel lock pliers, are shown in They have multiple size adjustments that make them good for gripping and applying limited torque to round, square, flat, and hexagonal objects. Their jaws may be straight, smooth, or curved. They are used mostly in plumbing and electrical. Page | 45  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SCREWDRIVER: It is a device used to insert and tighten screws or to loosen and remove screws. A screwdriver has a head or tip that connects with a screw, a mechanism to apply torque by rotating that tip, and a way to position and support the screwdriver. A typical manual screwdriver is made up of a roughly cylindrical handle, with a shaft fixed to the handle, including a tip shaped to fit a particular type of screw. The handle and shaft support and position the screwdriver and apply torque when rotated. The blade is made of tempered steel so it will resist wear, bending, and breaking. There are many different types of screwdrivers, identified by the type of screws they fit. Page | 46  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 WRENCHES/SPANNER: A wrench is a tool used to provide a mechanical advantage when torque is applied to hold and turn bolts, nuts, screws, and pipes. Wrenches are forged from steel alloy to prevent breakage. Wrenches are divided into two categories: nonadjustable and adjustable. OPEN WRENCHES/SPANNER: Open-end wrenches have open jaws on one or both ends of the wrench. Most jaw openings are offset from the shank portion of the wrench by 15 degrees. The wrench length is determined by the size of the jaw opening. Page | 47  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 COMBINATION WRENCH /SPANNER: It has a box wrench and an open-end wrench on opposite sides of the same tool. The two ends are usually the same size. BOX END WRENCH /SPANNER: It surrounds the nut, bolt head, or stud on all sides. It is available with both 6- and 12-point openings. The 12-point opening is more common because it may be used on both square and hexagonal bolt heads. Some models have ratcheting capability. ADJUSTABLE WRENCH/SPANNER: It has an adjustable end opening that comes in locking and non-locking styles. The locking style can secure the jaws in the desired position, so when properly adjusted, it will not slip. The non-locking style requires frequent readjustment and is prone to slipping. The adjustable wrench is used to tighten or loosen nuts and bolts, but never on a fastener that has been rounded off. Make sure the movable jaw is located on the side where the rotation will be done. Page | 48  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 ALLEN WRENCH: It is known as a hex key wrench. It is a short, L-shaped tool designed to turn bolts or screws with hexagonal heads. Allen wrenches usually come in sets of different-size wrenches. C-SPANNER WRENCHES: Two basic types of spanner wrenches are the hook-type and the pin-type. Hook- type spanner wrenches are either fixed or adjustable and are normally used to tighten fire hoses or similar couplings and locking nut in machinery applications that have a protruding lip. Pin-type spanner wrenches have pins protruding from the handle that fit into holes in the coupling or plate to be tightened or loosened. Spanner wrenches are special- purpose wrenches and are to be used only for their intended purpose. Page | 49  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 STILLSON WRENCH: It is used to connect or to turn cylindrical parts. It has jaws that bite into the surface of pipe to hold it for turning, and should not be used on plated pipes because it can damage the surface. It is used to screw pipes into elbows or other threaded items. CHAIN PIPE WRENCHES: It is having a section of bicycle-type chain permanently attached to the handle. The upper section of the head has teeth that mate with the links of the chain. The chain is wrapped around the pipe and pulled over the head section of the wrench to grip the pipe. Chain pipe wrenches will scratch the surface of the pipe. Page | 50  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 STRAP PIPE WRENCH: It is having a leather or canvas strap that is attached to the handle. The strap is looped around the pipe and back through the handle to grip the pipe. The strap pipe wrench will not scratch the surface of the pipe. HAMMER: A hammer is a tool used to deliver an impact to an object. Hammers are mostly used to drive nails, fit parts, or break up objects. There are many types of hammers designed for specific uses, which vary in shape and structure. Most hammers include a handle and a head, with most of the weight in the head. The strongest, safest hammers have heads made of tough alloy (two or more metals) or drop-forged steel. The two main types of hammers are claw and ball peen. Page | 51  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SLEDGEHAMMER: The sledgehammer is used for projects that need great force, such as breaking up concrete or driving heavy spikes or stakes. A sledgehammer head is made of a high-carbon steel, weighs between 2 and 20 pounds, and has a handle 14 to 36 inches long. The shape of a sledgehammer head depends on the job for which it will be used. SOFT-FACED HAMMER: Soft-faced hammers can deliver heavy blows to machined, highly polished, or soft surfaces without damaging the surface. Page | 52  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SAWS: They are tools with thin flat steel blades that have a row of spaced notches or “teeth” along the edge. The blade is fastened to a handle. Saws are available in various sizes and designs depending on their use and the material to be cut. The most common types of saws are handsaw (crosscut and ripsaw), one-man crosscut saw, two-man crosscut saw, backsaw, nest-of-saws, compass (keyhole) saw, coping saw, dovetail saw, and hacksaw. HAND SNIPS AND HAND SHEARS: Various types of hand snips and hand shears are used for cutting and notching sheet metal. All of the snips, shears, and nibblers are either manual or power operated. Hand snips are necessary because the shape, construction, location, and position of the work to be cut frequently prevent the use of machine-cutting tools. Page | 53  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CUTTING PUNCH: It has an open sharpened edge on one end and a solid shaft on the other end. The center portion of the punch is bowed for catching the metal scrap. Cutting punches are used to punch holes in the soft sheet metal or gasket sheet require struck with a hammer. Cable Cutter: The cable cutter is a tool used to cut copper or aluminum electric wire from #1 through 1000MCM. They come in four varieties: palm grip, manual two-handled units, ratchet cutters and electric cutters. Page | 54  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CHISELS: It is classified according to the shape of their points, and the width of the cutting edge denotes their size. The most common shapes of chisels are cold chisel, cape, round nose, and diamond point. Chisels are designed to cut and shape cold metal and are usually struck with a hammer. The flat or cold chisel is composed of hardened steel and has a tapered cutting edge on one end and a flat base on the other end. Sometime use round end chisel as punching tools to make permeant marks on the equipment for reference. C-CLAMP: The most common type of clamp, with a C- shaped frame made of forged steel or cast iron. It is used mostly to clamp metalwork. An adjustable screw changes the jaw opening, controlled by turning a wing nut or a sliding cross-pin handle. The size of the C-clamp identifies its jaw capacity, which is the largest object the frame can accommodate when the screw is fully extended. The depth of the throat is another important measure which determines how far in from the edge of the material the clamp can be placed. Page | 55  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 BENCH VISE: It is mounted on a workbench or table and is used to hold work pieces securely in place between two flat jaws. It is available in stationary or swivel models; the swivel model has a sliding spindle lockdown to hold the vise at different angles. The threaded spindle adjusts the jaw openings when you turn the sliding cross pin handle. Page | 56  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 JACKS: They are used to raise or lower work and heavy loads short distances. Some jacks are used for pushing and pulling operations. Others are used for spreading and clamping operations. WIRE BRUSH: It is a tool consisting of a handle and a brush made up of a large number of steel or brass wire bristles. It is an abrasive tool, used to clean rust and remove paint from surfaces. It can also be used to clean wire rope and chain. Wire brushes will leave marks on soft surfaces and can transfer oil and dirt if they are not kept clean between uses. Page | 57  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 FILES: Are used for cutting, smoothing off, or removing small amounts of metal, wood, plastic, or other material. Files are made in various lengths, shapes, and cuts. Every file has five parts the point, edge, face or cutting teeth, heel or shoulder, and tang. PULLERS: Used to remove a component such as a gear, a pulley, coupling hubs or a bearing from a shaft or hole. Pullers are available in various styles and can be used in different situations. Page | 58  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CHAIN HOISTS: It is come in a variety of designs and rated lifting capacities. The chain hoist consists of a hoist mechanism, two hooks, a ratchet lever, a selector lever, and a hand wheel. The hooks generally have a safety snap so that the load cannot accidentally come off the hook. The selector lever is used to select up or down movement. The hand wheel is used to quickly take up the slack in the chain before actual lifting begins. Hand chain hoists have been designed with built-in safety features that indicate when a hoist has exceeded its safe working capacity. If you use a hoist in a manner that exceeds its rated design limit. SLINGS: Slings are widely used for hoisting and moving heavy loads. Some types of slings come already made. Slings can be made of wire rope, fiber line, or chain. Page | 59  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 WIRE ROPE SLINGS: Wire rope slings offer the advantages of both strength and flexibility. These qualities make wire rope adequate to meet the requirements of most crane hoisting jobs; therefore, wire rope slings are used more often than fiber line or chain slings. FIBER LINE SLINGS: Fiber line slings are flexible and protect finished material better than wire rope slings. However, fiber line slings are not as strong as wire rope or chain slings and are more likely to be damaged by sharp edges. Page | 60  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CHAIN SLINGS: Chain slings are most often used for hoisting heavy steel items, such as rails, pipes, beams, and angles. Chain slings are the most appropriate type of sling for hot loads and loads that have sharp edges that might otherwise sever the sling components. HOOKS AND SHACKLES: It is provide a useful means of moving loads without tying directly to the object with a line, wire rope, or chain. Attach them to wire rope, fiber line, blocks, or chains. Use shackles for loads too heavy for hooks to handle. Hooks and shackles shall be inspected for and abnormality also don’t use if found pin bend or any cracks observed. Page | 61  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SCREW DRIVERS: Screw drivers are made out of tools steel hardened and tempered at the tip. They come in various size and shapes, which are used to turn screws with slotted heads. At a minimum, it is a feature on the screw that allows torque to be applied to it. Electrical application screw drivers should be insulated to avoid short circuiting and electrical shocks. 1. Slot The slot screwdriver has a single slot in the fastener head and is driven by a "common blade" or flat-bladed. The slotted screw is common in simple woodworking applications but is not often seen in applications where a power tool would be used because a power driver tends to slip out of the head and potentially damage the surrounding material. Page | 62  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 2. Cross A cross-recess screwdriver has two slots, oriented perpendicular to each other, in the fastener head; a slotted screwdriver is still used to drive just one of the slots. This type is usually found in cheaply made roofing bolts. The sole advantage is that they provide some measure of redundancy: should one slot be deformed in service, the second may still be used. Page | 63  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 PLIERS: Pliers are a hand tool used to hold objects firmly, possibly developed from tongs used to handle hot metal. They are also useful for bending and compressing a wide range of materials. The plier arrangement creates a mechanical advantage, allowing the force of the hand's grip to be amplified and focused on an object with precision. The jaws can also be used to manipulate objects too small or unwieldy to be manipulated with the fingers. Page | 64  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Plier Types: 1. Slip Joint Pliers Slip joint pliers have their jaws in line with their handle One side of the pliers usually has 2 holes that are connected by a slot for the pivot. The pivot is fastened to the outer side and shaped such that it can slide through the slot when the pliers are fully opened. They are used for a wide range of service involving gripping, turning and bending. 2. Diagonal Cutting Pliers Diagonal pliers (or wire cutters or diagonal cutting pliers or diagonal cutters) are pliers intended for the cutting of wire (they are generally not used to grab or turn anything). The plane defined by the cutting edges of the jaws intersects the joint rivet at an angle or "on a diagonal", hence the name. Page | 65  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 3. Side Cutting Pliers Side-cutting pliers (side-cutters) are principally used for holding, bending, and cutting thin materials or small gauge wire. 4. Combination Pliers Combination pliers or Lineman’s pliers are a type of pliers used by electricians and other trades men primarily for gripping, twisting, bending and cutting wire and cable. Linemen's pliers owe their effectiveness to their plier design, which multiplies force through leverage. Lineman's pliers have a gripping joint at their snub nose and cutting edge in their craw. Page | 66  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 5. Crimping Pliers Crimping is joining two pieces of metal or other ductile material by deforming one or both of them to hold the other. The bend or deformity is called the crimp. Crimping is most extensively used in metal working. Crimping is commonly used to fix bullets in their cartridge cases, for rapid but lasting electrical connections, securing lids on metal food cans, and many other applications. Because it can be a cold- working technique, crimping can also be used to form a strong bond between the work piece and a non-metallic component. 6. Wire Stripper A wire stripper is a small, hand-held device used to strip the electrical insulation from electric wires. A simple manual wire stripper is a pair of opposing blades much like scissors or wire cutters. The addition of a center notch makes it easier to cut the insulation without cutting the wire. This type of wire stripper is used by rotating it around the insulation while applying pressure in order to make a cut around the insulation. Since the insulation is not bonded to the wire, it then pulls easily off the end. Page | 67  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 DRILL PRESS: It is an electrically operated power machine originally designed as a metal working tool. Accessories, such as jigs, and special techniques make it a versatile woodworking tool as well. The OEM safety work instruction must be followed for this equipment before operating. Page | 68  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 GRINDER: Angle grinders know as aside grinder or disc grinder, it is a handled power tools and portable using in plant or any location for grinding abrasive cutting and polishing the meatal and other like plastic and fiber. There is another type called bench grinder consists of a tool rest, an abrasive wheel, and an encased motor assembly. The clamp is used for fastening the grinder to a working surface. The rest supports tools that are being ground. It is adjustable and may be moved from side to side. The abrasive wheel may be changed, depending upon the type of metal being ground. Page | 69  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 POWER DRILLS: Hand tools for drilling holes because they are faster and more accurate. With variable speed controls and special clutch drive chucks, they can also be used as electric screwdrivers. More specialized power-driven screwdrivers are also available, which have greatly increased the efficiency of many fastening operations in construction work. HEAT GUNS: Heat Guns are handheld machines that generate hot air for a wide variety of tasks. For example, heat guns are used to strip old paint, shrink materials like film, dry wood, or tubing, bend hard plastic, or thaw frozen pipes. These special guns need electricity to produce heat; generally, the temperature of hot air is around 100 degrees Celsius to 550 degrees Celsius. The heat directed toward the target is through a nozzle and spreads around by an electric fan. Page | 70  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 IMPACT TORQUE WRENCH: An impact wrench (also known as an impactor, impact gun, air wrench, air gun, rattle gun, torque gun, windy gun) is a socket wrench power tool designed to deliver high torque output with minimal exertion by the user, by storing energy in a rotating mass, then delivering it suddenly to the output shaft. The compressed air is the most common power source, although electric or hydraulic power is also used, with cordless electric devices becoming increasingly popular. Page | 71  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 ELECTRIC SOLDERING IRON: A soldering iron is a hand tool used in soldering. It supplies heat to melt solder so that it can flow into the joint between two work pieces. A soldering iron is composed of a heated metal tip and an insulated handle. Heating is often achieved electrically, by passing an electric current (supplied through an electrical cord or battery cables) through a resistive heating element. Page | 72  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 ELECTRIC AIR BLOWER: It is operated through a motor via electricity which rotates the blades that are attached to a shaft. The blower is a machine to move air at a moderate pressure. Or simply, blowers are used for blowing air/gas. Page | 73  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 LATHES: Lathes hold and spin materials so that they can be worked and shaped. Powered lathes allow the crafter to focus on working the material instead of having to constantly turn the spindle. Page | 74  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 PLASMA POWER CUTTER TOOLS: Plasma cutting is a process that cuts through electrically conductive materials by means of an accelerated jet of hot plasma. Typical materials cut with a plasma torch include steel, stainless steel, aluminum, brass and copper, although other conductive metals may be cut as well. HYDRAULIC CABLE CUTTER: Hydraulic power cable cutters are hydraulic tools at 720 bar (10.400 Psi) that can be used anywhere to cut power cables. Hydraulic cutters are used a lot in the construction industry, dismantling and demolishing, and infrastructure. Page | 75  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Knowledge review 1. Screwdriver can used as lever or chisel for temporary activity usage? a) True b) False 2. Is the chisel a power tool? a) True b) False 3. What type of tool is a chain block? a) Hand Tools b) Power Tools c) Measurement Tools d) Cutter Tools 4. The following are power tools, except: a) Pipe Wrench b) Impact Wrench c) Electric Cutter d) Hydraulic Crimper Page | 76  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 5. What is the name of this measuring tool? a) Vernier Caliper b) Outside Caliper c) Micrometer d) Inside Caliper 6. Is a tool use to tighten or loosen nuts, bolts, studs and pipes? a) Wrench b) Screwdriver c) Pliers d) Hammer 7. Hand tools can be manually use by employing: a) Mechanical force b) Electrical power c) Battery d) All of the above 8. Identify this type of tool. a) Open-end spanner b) Combination spanner c) Open spanner d) Ring spanner Page | 77  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 9. Is a tool use to drive bolts and screws with hexagonal sockets in their heads? a) Screwdriver b) Allen Key/Wrench c) Hummer d) Plier 10. What do you call a tool use to perform a job using only your hands? a) Hand Tools b) Measurement Kit c) Kitchen Tools d) PPE 11. There are several types of power tools, including electric, liquid fuel, hydraulic, powder-actuated, _____________and ____________. a) Pneumatic b) Hydraulic c) Both A & B Answers Page | 78  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 ELECTRICAL SAFETY Page | 79  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CONTENT SN SUBJECT PAGE NUMBER 1 Learning Objectives 73 2 Basic of Electricity and Shock 74 3 Dangers of Electricity 76 4 Shock hazards 78 5 Electrical Fire Hazards 87 7 Electrical Arc flash and Arc blast 93 8 Protection against electrical hazard 96 Page | 80  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 OBJECTIVES SN OBJECTIVE 1 Understanding Basic Electrical Hazards Page | 81  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Basic of Electricity and Shock WHAT AFFECTS THE FLOW OF ELECTRICITY? Electricity flows more easily through some materials than others. Some substances such as metals generally offer very little resistance to the flow of electric current and are called “conductors.” A common but perhaps overlooked conductor is the surface or subsurface of the earth. Glass, plastic, porcelain, clay, pottery, dry wood, and similar substances generally slow or stop the flow of electricity. They are called “insulators.” Even air, normally an insulator, can become a conductor, as occurs during an arc or lightning stroke. HOW DOES WATER AFFECT THE FLOW OF ELECTRICITY? Pure water is a poor conductor. But small amounts of impurities in water like salt, acid, solvents, or other materials can turn water itself and substances that generally act as insulators into conductors or better conductors. Dry wood, for example, generally slows or stops the flow of electricity. But when saturated with water, wood turns into a conductor. The same is true of human skin. Dry skin has a fairly high resistance to electric current. But when skin is moist or wet, it acts as a conductor. This means that anyone working with electricity in a damp or wet environment needs to exercise extra caution to prevent electrical hazards. WHAT CAUSES SHOCKS? Electricity travels in closed circuits, normally through a conductor. But sometimes a person’s body — an efficient conductor of electricity — mistakenly becomes part of the electric circuit. This can cause an electrical shock. Shocks occur when a person’s body completes the current path with:  both wires of an electric circuit.  one wire of an energized circuit and the ground.  a metal part that accidentally becomes energized due, for example, to a break in its insulation.  another “conductor” that is carrying a current. When a person receives a shock, electricity flows between parts of the body or through the body to a ground or the earth. WHAT KIND OF BURNS CAN A SHOCK CAUSE? Burns are the most common shock-related injury. An electrical accident can result in an electrical burn, arc burn, thermal contact burn, or a combination of burns. Page | 82  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Electrical burns are among the most serious burns and require immediate medical attention. They occur when electric current flows through tissues or bone, generating heat that causes tissue damage. Arc or flash burns result from high temperatures caused by an electric arc or explosion near the body. These burns should be treated promptly. Thermal contact burns are caused when the skin touches hot surfaces of overheated electric conductors, conduits, or other energized equipment. Thermal burns also can be caused when clothing catches on fire, as may occur when an electric arc is produced. In addition to shock and burn hazards, electricity poses other dangers. For example, arcs that result from short circuits can cause injury or start a fire. Extremely high-energy arcs can damage equipment, causing fragmented metal to fly in all directions. Even low-energy arcs can cause violent explosions in atmospheres that contain flammable gases, vapors, or combustible dusts. WHY DO PEOPLE SOMETIMES “FREEZE” WHEN THEY ARE SHOCKED? When a person receives an electrical shock, sometimes the electrical stimulation causes the muscles to contract. This “freezing” effect makes the person unable to pull free of the circuit. It is extremely dangerous because it increases the length of exposure to electricity and because the current causes blisters, which reduce the body’s resistance and increases the current. The longer the exposure, the greater the risk of serious injury. Longer exposures at even relatively low voltages can be just as dangerous as short exposures at higher voltages. Low voltage does not imply low hazard. In addition to muscle contractions that cause “freezing,” electrical shocks also can cause involuntary muscle reactions. These reactions can result in a wide range of other injuries from collisions or falls, including bruises, bone fractures, and even death. WHAT SHOULD YOU DO IF SOMEONE “FREEZES” TO A LIVE ELECTRICAL CONTACT? If a person is “frozen” to a live electrical contact, shut off the current immediately. If this is not possible, use boards, poles, or sticks made of wood or any other nonconducting materials and safely push or pull the person away from the contact. It’s important to act quickly but remember to protect yourself as well from electrocution or shock. How can you tell if a shock is serious? A severe shock can cause considerably more damage than meets the eye. A victim may suffer internal hemorrhages and destruction of tissues, nerves, and muscles that aren’t readily visible. Renal damage also can occur. If you or a coworker receives a shock, seek emergency medical help immediately. Page | 83  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 DANGERS OF ELECTRICITY WHAT IS THE DANGER OF STATIC ELECTRICITY? Static electricity also can cause a shock, though in a different way and generally not as potentially severe as the type of shock described previously. Static electricity can build up on the surface of an object and, under the right conditions, can discharge to a person, causing a shock. The most familiar example of this is when a person reaches for a doorknob or other metal object on a cold, relatively dry day and receives a shock. However, static electricity also can cause shocks or can just discharge to an object with much more serious consequences, as when friction causes a high level of static electricity to build up at a specific spot on an object. This can happen simply through handling plastic pipes and materials or during normal operation of rubberized drive or machine belts found in many work sites. In these cases, for example, static electricity can potentially discharge when sufficient amounts of flammable or combustible substances are located nearby and cause an explosion. Grounding or other measures may be necessary to prevent this static electricity buildup and the results. Dangers of Electricity include a variety of hazards that include Electric Shock, Psychological Damage, Physical Burns, Neurological Damage and Ventricular fibrillation resulting in death. Any form of energy, when not properly controlled or harnessed, can result in serious danger to those who use it. The risks inherent with electric power can generally be divided into two categories: direct and indirect. The direct danger is the damage that the power itself can do to the human body, such as stoppage of breathing or regular heartbeats, or burns. The indirect dangers of electricity include the damages that can result to the human body as a result of something caused by electric shock, such as a fall, an explosion, or a fire. Page | 84  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Electricity at any voltage can be dangerous and should always be approached with caution. An electric shock can occur upon contact of a human or animal body with any source of voltage high enough to cause sufficient current flow through the muscles or nerves. The minimum current a human can feel is thought to be about 1 milliampere (mA). As little as 80 milliampere, can seize the heart muscle. The current may cause tissue damage or heart fibrillation if it is sufficiently high. A fatal electric shock is referred to as electrocution. Electricity at any voltage can be dangerous and should always be approached with caution. An electric shock can occur upon contact of a human or animal body with any source of voltage high enough to cause sufficient current flow through the muscles or nerves. The minimum current a human can feel is thought to be about 1 milliampere (mA). As little as 80 milliampere, can seize the heart muscle. The current may cause tissue damage or heart fibrillation if it is sufficiently high. A fatal electric shock is referred to as electrocution. Page | 85  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SHOCK EFFECTS PSYCHOLOGICAL The perception of electric shock can be different depending on the voltage, duration, current, path taken, frequency, etc. Current entering the hand has a threshold of perception of about 5 to 10 mA (milliampere) for DC and about 1 to 10 mA for AC at 60 Hz. Shock perception declines with increasing frequency, ultimately disappearing at frequencies above 15-20 kHz. BURNS Dangers of Electricity include physical burns. High-voltage (> 500 to 1000 V) shocks tend to cause internal burns due to the large energy (which is proportional to the duration multiplied by the square of the voltage) available from the source. Damage due to current is through tissue heating. In some cases, 16 volts might be fatal to a human being when the electricity passes through organs such as the heart. VENTRICULAR FIBRILLATION A low-voltage (110 to 220 V), 50 or 60-Hz AC current travelling through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 60mA. With DC, 300 to 500 mA is required. If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA, (AC or DC) can cause fibrillation. Fibrillations are usually lethal because all the heart muscle cells move independently. Above 200mA, muscle contractions are so strong that the heart muscles cannot move at all. NEUROLOGICAL EFFECTS Other Dangers of Electricity cause interference with nervous control, especially over the heart and lungs. Repeated or severe electric shock which does not lead to death has been shown to cause neuropathy. When the current path is through the head, it appears that, with sufficient current, loss of consciousness almost always occurs swiftly. Page | 86  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 WHAT IS ELECTRICAL SHOCK?  Every movement- conscious or unconscious- of human / animal body is due to contraction of muscles reacting to minute electrical current from brain through nerve system.  When electrical current through nerve system increases due to electrocution, muscles react very violently. This causes the feeling of shock.  This violent reaction may cause permanent damage to very critical organs of body like heart, lungs, wind pipe, brain etc.  An electric shock can occur upon contact of a human body with any source of voltage high enough to cause sufficient current through the muscles. The minimum current a human can feel is thought to be about 1 milliampere (mA). The current may cause tissue damage or fibrillation if it is sufficiently high. Death caused by an electric shock is referred to as electrocution. Generally, currents approaching 100 mA are lethal if they pass through sensitive portions of the body. Page | 87  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SEVERITY OF ELECTRIC SHOCK DEPENDS UPON:  Amplitude of current. CHART SHOWING OVERALL  Nature of current. EFFECTS OF RESISTANCE  Duration of electrocution. /VOLTAGE AND CURRENT  Condition of body (dry or wet).  Psychological condition.  Position of hands & legs. (Current flow path)  Ambient condition-- Humidity & Temperature.  CO2 / O2 Content in atmosphere (With more CO2 or less O2, the body resistance reduces. Figure summarizes the overall effects of resistance, voltage, and current in a shock appraisal chart. It is clear from the chart that the resistance values are set at a maximum of 1000 ohms at and beyond the 600volt level. This is due to the immediate penetration of the skin at the 600-volt shock level, thus allowing the current to travel through the body without the skin resistance being a factor. Entrance and exit wound injuries are generally present when this occurs. Page | 88  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 AMPLITUDE OF CURRENT: Table illustrates average values of current and the effects. The values listed are average and are not meant to provide specific effects for every person. Page | 89  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 To further illustrate how easily a person can receive a fatal shock, consider a voltage that is common to every location in the Saudi Arabia, 120-volts. Under average working conditions where the person is perspiring and has a resistance of only 1000-ohms from hand-to-hand, using the simple Ohm’s Law formula (current equals the voltage divided by the resistance) the current flow will be 0.12 amperes or 120 mA. Examination of Table shows that this value of current will probably cause ventricular fibrillation which is, in most cases, fatal. TIME CURRENT ZONES FOR ALTERNATING CURRENT AS PER VENTRICULAR FIBRILLATION AS A FUNCTION OF SHOCK DURATION IEC 479-1 (1984) Page | 90  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 CURRENT FLOW DURATION: The longer the duration of the shock the higher is the likelihood of death. This is because the thermal heat inside the tissues is a form of energy and therefore proportional with time. Also, if the current interferes with the operation of the heart or lungs, the longer the duration, the longer is the chance for death from respiratory or cardiac arrest. When the current is above the leg go threshold, the person is in capable of releasing his/her grip on the wire and the shock duration is often longer. Fibrillation is the shocking of your heart into a useless flutter. The longer you are shocked, the more chance there is for your heart to begin fibrillating. Most people who die from electric shock die from fibrillation. The longer you are shocked, the less current is needed to cause heart fibrillation. Page | 91  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 NATURE OF CURRENT: AC is more dangerous than DC. AC with low frequency and voltage is more dangerous than high frequency and voltage. Low-frequency (50- to 60-Hz) AC (60 Hz) is more dangerous than high frequency AC and is 3 to 5 times more dangerous than DC of the same voltage and amperage. AC WAVEFORM Page | 92  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 Low-frequency AC produces extended muscle contraction (tetany), which may freeze the hand to the current's source, prolonging exposure. DC is most likely to cause a single convulsive contraction, which often forces the victim away from the current's source. AC's alternating nature has a greater tendency to throw the heart's pacemaker neurons into a condition of fibrillation, whereas DC tends to just make the heart stand still. Once the shock current is halted, a "frozen" heart has a better chance of regaining a normal beat pattern than a fibrillating heart. This is why "defibrillating" equipment used by emergency medics works: the jolt of current supplied by the defibrillator unit is DC, which halts fibrillation and gives the heart a chance to recover. BODY RESISTANCE: Male with dry skin 100 M Ohm to 600 M Ohms Male with wet skin 1.0 M Ohm Female & Children 50 % of Male Electric current is capable of producing deep and severe burns in the body due to power dissipation across the body's electrical resistance. DC CURRENT WAVEFORMS Page | 93  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 AMBIENT TEMPERATURE AND HUMIDITY: High ambient temperature results into more perspiration which makes body wet and so body resistance reduces. Due to high humidity in the atmosphere, body does not get dried up which results into low body resistance. CO2 and O2 content in the air: Lower oxygen and higher carbon dioxide reduce resistances of the body. CONDITION OF FLOORING:  Wet floor offers less than 100-ohm resistance.  Insulated rubber mat offers more than 10-million-ohm resistance.  Dry, varnished wood was used as support insulator in LT panels.  Wet wood can give path to leakage current. CURRENT FLOW PATH: Current passing through the skin is not as harmful as current passing through vital organs. The fatal current often pass through the heart, lungs and brain. A very small amount of current passing directly through the heart can cause cardiac arrest. The heart muscle could beat out of step resulting in insufficient blood being pumped through the body. A current in the spine cord may also alter the respiratory control mechanism. The two most dangerous paths that current can take through your body are (1) from hand to CURRENT FLOW PATH THROUGH HAND TO LEG hand and (2) from left hand to either foot. The second path is the MOST dangerous since the current will flow through both your heart and other vital organs. Page | 94  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 FIRE HAZARDS SHORT CIRCUIT IN ELECTRICAL NETWORK WITH INADEQUATE PROTECTION:  A short circuit in an electrical circuit is one that allows a current to travel along a different path from the one originally intended.  A short circuit is an abnormal low-resistance connection between two nodes of an electrical circuit that are meant to be at different voltages. This results in an excessive electric current (overcurrent) limited only by the resistance of the rest of the network and potentially causes circuit damage, overheating, fire or explosion.  In mains circuits, short circuits may occur between two phases, between a phase and neutral or between a phase and earth (ground). Such short circuits are likely to result in a very high current and therefore quickly trigger an over current protection device.  During short circuit, over current protection device should trip the circuit immediately otherwise severe damage will occur. SHORT CIRCUIT IN PLUG OUTLET Page | 95  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 SWITCHING ON ELECTRICAL POWER IN FAULTY CONDITION:  During fault condition, electrical circuit must be isolated and reason of fault should be checked.  If these circuits are made to ON repeatedly during fault condition, may result to fire or explosion. STATIC ELECTRICITY:  Static electricity is a stationary charge that builds up on some objects. Walking across a carpet in a dry atmosphere will produce a static charge that can produce an arc when discharged. Other kinds of motion can cause a build-up of charge, including the pulling off of clothing, operation of conveyor belts, and the flowing of liquids.  The generation of static electricity cannot be prevented absolutely, but this is of little consequence because the development of electrical charges may not in itself be a potential fire or explosion hazard. For there to be an ignition there must be a discharge or sudden recombination of the separated positive and negative charges in the form of an electric arc in an ignitable atmosphere. Page | 96  0 255 4 227 77 217 247 159 205 30 82 77 217 247 223 0 66 5 77 217 247 LIGHTING STROKE:  Lightning is a natural phenomenon occurring during electrical storms. It is a discharge of atmospheric electricity and is accompanied by a vivid flash of light, commonly from one cloud to another, sometimes from a cloud to the earth.  Fifty five percent of fires caused by lightning strikes occur outside, igniting trees, brush, grass, or other outside materials (Figure 3). Almos