Voltage Specs & Transformers

Voltage Specification

• HT, or high tension, ranges from 11 Kilo volts to 33KV.
• LT, or low tension, ranges from 220 to 440 Volts.
• ST, or supper tension, is above 33 Kilo volts.

Transformer

• Transformer is a static device which transforms voltage from primary to secondary without changing the frequency.
• Transformers operate on the principle of Faraday's Law of Electromagnetic induction.
• Transformer types come down to usage, construction, and voltage level.
• Usage includes power or distribution transformer.
• Construction consists of core, shell, and berry type.
• Voltage level is categorized by step down or step up.
• Distribution transformers of A/C commonly are utilized for power distribution within areas of the primary delta type and secondary star type.

Transformer Safety

• Safety measures when monitoring a transformer involves checking oil level in the conservator tank, oil temperature (less than 50 'C), winding temperature (less than 60 'C), and check for oil leakage.
• Check for abnormal sound or noise and avoid potential vibration as well as ensure that the silica gel is in good condition.
• 4 earthing pits are required for commencing a transformer: 2 for body earthing and 2 for neutral earthing.
• Earthing the transformer neutral keeps the load balance, provides single phase line, allows for line tests, and protects the machines.
• Without a neutral, under unbalanced load conditions, a phase can return power to the source and damage the same.

Transformer: OLTC and Breathers

• OLTC (ON LOAD TAP CHANGER) or CHANGEOVER changes the tap of a transformer on load, depending on voltage variation and is always is connected to the primary side
• A breather absorbs moisture entering in the transformer tank along with air.
• Breathing transfers air from the atmosphere and passes it through silica gel according to oil level variation in conservator tank with the breather is fitted to top of the conservator tank through a pipe.
• Temperature of transformer oil raises as winding temperature raises and expand with the reducing temp, oil temp also reduces as air compresses.
• Atmospheric air enters the transformer through the breather where moisture contents in the air are observed by the silica gel.
• Silica gel helps with maintaining the Transformer oil's insulating property where it turn from blue to slowly loses its blue colour and turn in to white.

Silica Gel and Bucholz Relay

• Silica gel absorbs the moisture in the transformer oil tank.
• A good condition of silica gel is indicated by a blue color where as a bad condition is indicated by a pink color.
• Bucholz relay is a protective device protecting the transformer against overload and short circuit in the winding having a two float system: top and bottom float.
• The top float is used for the alarm circuit and the bottom float used for tripping the breaker in case of service faults
• Alternatively it is a protection relay, which operates on the excessive formation of the oil vapors or gas inside the transformer tank due to any internal fault and is fitted between the tank and conservator.
• In the event of a heavy internal fault (short circuit, earth leakage or failure of insulation occurs in the system) the temperature of the oil rapidly increases.
• Oil expands quickly and rushes to the conservator through the relay, tripping the tripping coil which saves the transformer. The static device has two switches or relays like the Alarm switch and a Trip switch.
• A Buchholz relay identifies the nature of a fault by inspecting which gas is collected with: colorless gas (air), white gas (decomposition paper insulation), yellow gas (decomposed wooded insulation), gray gas (decomposed oil due to heating of core), and Black gas (decomposition oil due to electric arc).

Transformers

• Normal oil level in the conservator tank maintained at half whereas remaining half provides to expansion or contraction of oil.
• Normal oil level of transformer roughly 75%.
• VCB is a vacuum circuit breaker used up to 33KV and contains fixed and moving contacts to quench the arc, mainly used on low current and high voltage
• Cubical meter consists of CT and PT to mount the load of KW, KVA, PF, MD, and Volts.
• The formula for PF (Power Factor) in H T side is the ratio of real power(KW) to the apparent power(KVR), PF=(KWH/KVA).

Transformer: Safety and Specifications

• Acceptable current for humans is 30 milli amps.
• The safety seals are a tag and seal for authorized personnel only to handle.
• Procedures during transformer oil filtration requires checking oil level in transformer, removing silica gel, and performing HV tests.
• The acceptable oil level in conservator tank is between L (low) and H (high).
• Minimum dielectric strength of transformer oil is 30KV, with low dielectric strength at 20 KV and max 60kv.
• Dielectric strength is the ability of the material to withstand voltage per unit thickness of the material, without breaking down by not rupturing.
• The provided safety relays and alarms include over current relay, earth fault relay, Bucholz alarm, Bucholz trip, Winding temperature alarm/trip, and Tripping relay.
• Standard safety measures involve Oil level, Oil temperature, Winding temperature, Winding tap position, Silica gel colour, Bucholz relay, Input & Output voltage & current.
• Human acceptable current is 30 milli Amps while the cubical meter utilizes C.T & P.T. to mount the load of KW,KVA,PF,MD, VOLTS.
• A star connection has the same phase and line current, but the line voltage is equal to √3 times of phase voltage and in delta connection, the phase voltage and line voltage is the same, but current is equal to √3 times the phase current.
• OT or Oil Temperature, has an acceptable range of 65°C to 80° C with the alarm at in maximum range is 85°C while WT winding temperature acceptable range between 65°C to 85°C , with alarm starts at 90°C.

DG set(Diesel Generator)

• Parts and applications are:
  • Permanent magnet generator supplies the magnetic power.
  • AVR keeps the voltage within the limit.
  • 1/2 moon coupling plate couples the exhaust with the engine.
  • 2 self starters apply the starting torque to the engine.
  • Battery charging alternator(Dynamo) charges the battery while running.
  • 2 super by pass filter filters the engine oil.
  • Priming pump(2hp) supplies the oil to engine parts.
  • 4 Coolant filter filters the coolant.
  • Turbo charger(2nos) supplies the air to the engine.
  • Exhaust bellow(2nos) disposes the smoke to outside.
  • Oil/Air filter filters the engine oil/air from outside respectively.
  • Engine oil stick (Dip stick) finds the engine oil level.
  • Heat exchanger tank transfers the heat from the water.
  • Water pipe coupling assembly flows the water near the engine.
  • Fly wheel-1500 rpm runs the engine.
  • Coolant glass indicator finds the water level in the expansion coolant tank.
  • Fuel pump supplies the fuel.
  • Activator and fuel supply controls the fuel.
  • Lube oil filter(4nos) filters the lube oil.
  • Fuel water separator (2nos) filters the water in the fuel.
  • Engine oil pump supplies the oil.
  • Oil pressure sensing finds the pressure of the oil.
  • Water temperature sensor finds the temperature of the water.
  • Low coolant water level sensor finds the water level in the expansion coolant tank.
  • Magnetic pickup finds the speed of flywheel.
  • Vacuum indicator finds the amount of dust particles in the air filter.
  • Cooling towers supplies the chilled water to the eingine.

Diesel Engine, Alternator,

• Diesel generators or diesel engine converts fuel energy to mechanical.
• An engine is a mechanical machine generating energy from a power source.
• An alternator AC power-generating machines converts mechanical energy into electrical.

EFC Governor and Turbo Charger

• An electric fuel controller is called a governor which is used on engine for controlling its speed either in a synchronous mode or with adjustable droop and EFC governor is used to PT fuel system.
• A turbo charger sucks air from the outside world, and uses the engine's fuel for burning
• Compressor wheel RPM OF 10150 has better efficiency.

Breating States Its Function

• Breating process of the engine; supply for the engine to continue burning.

What is Breather

• When under heavy load, it removes excess fuel from combustions.

What is Thermostat

• It is a temperature reader, it can regulate temperature depending on needs.

Battery Charger

• Can supply between 3 amps 12amps 6v 13v 24valts.

Priming Pump

• Three-phase to regulate fluids and generators are required.

Self Starter

• It is a 24 volt DC regulator that helps with supplying starting torque.

Battery Type

• A simple lead battery is required for the generators to produce power.

Earthing Requirements for DG

• 4 earth pits to commission the system
• 2 for body earth and 2 for neutral earth.

AVR Failure

• When the generator reaches the output voltage it becomes and affects the overall speed.

Mechanical Interlock

• The lock is required when the key in switch is being used.

GCP

• GCP regulates generator controls.

Battery Capacity

• 12valts, 120, ah-180ah

Low Level Diesel

• Low diesel levels between 150-200l

Bcheck Parts

• Check the radiator for filter or any other obstructions.

Meters

• Power meter measures current, voltage and general load.

PH reading

• Should be below 9 ppm

AVR

• Is designed to regulate voltage and currents.

Primary Pumps

• It is designed for lubricating engine parts.

Alternator Safety

• Watch each battery.

ECU

• ECU controls most perametors such as water and oil.

Pressure Relef Valve

• It is required to ensure pressure in the lines isn't high.

Governor

• To control current and flow.

Main Parts of a Engine

• Radiator, turbo charger and fuel tanks

Alternator

• Stators, relays and rotors

Daily Maintenence Checks

• Different types of repairs required.

Parallel operation

• 5W40 oil and a 12v battery to regulate amps.

Set synching

• Voltage to be same in each area as required, as well as same rates.

Synching Notes

• DG sets on all main breakers to stop mode.
• Check line monitors on master dg in standy

Parallel Info

• DG sets to run in synch until load on any of the generators.
• Automatic signals given to transfer load.

AUTO Load Sharing

• Software is easier to use and add to new areas.

PowerFactor

• The angle between both the voltage and currents is known as "power factor".

UPS

• Devices uninterrupted during a voltage or surge.

Earth

• Separate earth is used for single phase.

offline UPS

• Emergency back up for light

Batteries

• A batter charger converts AC power.

Measures

• Voltage, Current levels.

on line ups

• Will still operate whether the mains power comes online

Main parts

• Static switches.

Rectifiers

• Are used to convert Ac supply toDC supply.

Main Bypass Switch

• Required for emergency functions to reduce low load

Temperatures

• Temperatures to be controlled between 20-22 c

Perametors

• Battery Voltage and load

Intruptions

• High and low voltages.

Detections

• Heat to reduce load.

Steps

• Check alerms and vendors.

Ups safety

• Reduce the load.

AHU

• Filter, cooling, cabinet and fans.

Cooling cycle

• Compressors and lines.

Pressure

• Lines need high amounts of power to transfer liquid.

Low Pressures

• To reduce vapor.

Function

• Main function reduce pressure.

Refrigeration

• Mostly gasses are liquid.

Checks Required

• Temperatures to to be monitored.

HVAC

• Heating and ventilation.

PSI

• 14 in total is what one bar can deliver.

Temperatures HVAC

• Most rooms require a minimum of 19c air.

AHU

• Air needs fitures and motors.

Refrigeration Phase

• Convert heat and high pressure, back to warm.

SOPs

• SOP is required for various functions

Mode Settings

• Different mode.

Cooling. Mode

• Liquid cooling and pressures.

Pressure Temp

• Different type of temperature settings.

Compressor Cycles

• Different cycles for the compressor depending on temp, conditions and loads

Air Conditioner

• The cycle consist of compresors

Voltage to gas

• Pressures and type of gases being used.

Types of compressrs Types are

• Pumping

Gas Use

• 22 is a gas commonly used for splits R-22 (Freon) for Split/Central AC's

Temperature

• Normal range is +4 to water

Cleaning and maintiences

• Different type of gasses to push the fluid.

Parts required

• Double windows.

Reg Valves

• Can be cooled and set temperature.

Saftey Seal

• Two type.

ISOS. Reqeuirements

• Checklists and so on.

SOO

• Power to run.

Lights

• Emergency to come and see all equipment working

Activites

• Electrical to each sector.

Power

• Air Conditioning

AHU

• Different lights.

Air and water

Regulators