B11 LMSS Module 5

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Questions and Answers

What does 'Shall' indicate in regulatory terms?

Optional compliance measures.

Mandatory requirements. (correct)

Preferred methods of operation.

A suggestion for best practice.

Which of the following best describes a 'Listed' item?

Equipment with no inspection records.

Equipment produced without authority oversight.

Equipment that is under a trial phase.

Equipment that meets designated standards after testing. (correct)

What is a 'Controlled Stop'?

Stopping a machine by cutting off all power immediately.

An automatic stop without safety checks.

A manual method of shutting down a machine.

Stopping motion while maintaining power to actuators. (correct)

What defines a 'Hazardous Condition'?

An exposure to potential harm that can occur currently or in the future. Signup and view all the answers

What does 'Should' imply in a safety regulation context?

It is a recommendation that is advised but not mandatory. Signup and view all the answers

Which of the following describes the term 'Safety Circuit'?

The section containing devices for safety-related functions. Signup and view all the answers

What is meant by 'Uncontrolled Stop'?

Stopping machine motion by cutting power abruptly. Signup and view all the answers

What is the significance of compliance for existing machinery under the regulations?

Changes must align with current standards but are not retroactive. Signup and view all the answers

What is the primary purpose of machine guarding according to the standards?

To protect employees from operational hazards Signup and view all the answers

Which of the following is a method of proving a repeat violation under § 1910.212(a)(1)?

The cited employer had knowledge of violations Signup and view all the answers

In the case of Secretary v Loren Cook, what defense did Cook establish?

Technological and economic infeasibility for retrofitting machines Signup and view all the answers

What incident prompted OSHA to seek penalties from Wal-Mart in 2018?

A trolley incident involving an employee in an automated system Signup and view all the answers

What does 1910 Subpart O require concerning hazardous energy control?

Establishment of minimum performance requirements Signup and view all the answers

Which of these hazards can machine guarding protect against?

Point of operation hazards and rotating parts Signup and view all the answers

What was the economic penalty sought against Wal-Mart for the trolley incident?

$126,749 Signup and view all the answers

Which aspect was critical for establishing a repeat violation in the Secretary v Loren Cook case?

Knowledge of the violative conditions Signup and view all the answers

What is the primary purpose of the Occupational Safety and Health Act of 1970?

To prevent workers from being killed or seriously harmed at work Signup and view all the answers

What is the role of the Occupational Safety and Health Administration (OSHA)?

To set and enforce protective workplace safety and health standards Signup and view all the answers

Which of the following is a necessary element to prove a violation of the General Duty Clause?

There was a feasible and useful method to correct the hazard Signup and view all the answers

What is codified in 29 CFR 1910?

OSHA standards directly written into law for general industry Signup and view all the answers

Under the General Duty Clause, what does an employer need to ensure regarding recognized hazards?

The workplace must be free from recognized hazards that could cause injury or harm Signup and view all the answers

What department is OSHA part of?

Department of Labor Signup and view all the answers

Which of the following is NOT a responsibility of OSHA?

Providing legal representation for employees Signup and view all the answers

How can an employer demonstrate compliance with the OSH Act?

By conducting regular safety audits of the workplace Signup and view all the answers

What is the definition of risk reduction?

Any action or means used to eliminate hazards and/or reduce risks Signup and view all the answers

What does the acronym ALARP stand for?

As Low As Reasonably Practicable Signup and view all the answers

Which term is considered synonymous with acceptable risk?

Tolerable risk Signup and view all the answers

What is the primary safety control method used to prevent inadvertent re-energization of machinery?

Tagout Signup and view all the answers

What are the responsibilities of a supplier in hazardous energy control?

Designing equipment to allow users to control hazardous energy Signup and view all the answers

Who is responsible for complying with the hazardous energy control program?

All of the above Signup and view all the answers

Which of the following is NOT a correct definition of lockout?

Tagging the energy-isolating device Signup and view all the answers

Which regulation outlines the employer's responsibility for employee safety under OSHA?

29 CFR 1910 Signup and view all the answers

What is a key function of protective devices on a machine?

To provide interlocking of the electrical circuit Signup and view all the answers

Where should hand controls be mounted to minimize risks for operators?

Not less than 0.6m (2ft) above the servicing level Signup and view all the answers

What is the minimum enclosure protection type specified?

Type 1 Signup and view all the answers

What color should an emergency stop actuator be?

Red on a yellow background Signup and view all the answers

Which conductor is required to be insulated?

All conductors Signup and view all the answers

What is the requirement for the connections of conductors?

All connections secured against accidental loosening Signup and view all the answers

Which of the following colors is used for ungrounded AC control conductors?

Red Signup and view all the answers

What type of conductors is required to be copper?

All conductors referenced Signup and view all the answers

What is the purpose of identification tags on conductors?

To ensure clarity and prevent confusion in the physical environment Signup and view all the answers

What should be done to protect conductors against fraying?

Terminate shielded conductors properly Signup and view all the answers

What is required for terminals accepting more than one conductor?

They must be identified for that purpose Signup and view all the answers

What is the minimum working space in front of control cabinets?

762mm (30 inches) or the width of the opening, whichever is greater Signup and view all the answers

What is the defined characteristic of stranded conductors?

They must adhere to specific standards as per Table 12.2.2 Signup and view all the answers

Study Notes

NFPA 79 Key Definitions

Shall: Indicates mandatory requirements.
Should: Suggests recommendations or advice, not required.
Listed: Equipment or services evaluated by an authoritative organization, meeting designated standards.
Direct Opening Operation: Achieved by the movement of a switch actuator through non-resilient members, without relying on springs.
Hazardous Condition: A scenario where a person may face immediate or long-term harm.
Safety Circuit: Part of a control system performing safety-related functions to maintain safety.
Controlled Stop: Machine halts while retaining power to the actuators.
Uncontrolled Stop: Machine halts by cutting power, initiating brakes or other mechanical stops.

NFPA 79 Control Functions

Control Functions in Failure Scenarios:
- Protective devices are essential (interlocks, guards, trip devices).
- Electrical circuits must include protective interlocking.
- Proven circuit techniques and components should be utilized.
- Partial or complete redundancy may be required.
- Functional testing should be provisioned.

NFPA 79 Operator Interface & Control Devices

Controls must be rigidly mounted in clean, dry areas to minimize damage.
Hand controls must be positioned at least 0.6 meters above the servicing level.
Operator positions must avoid hazardous situations and minimize inadvertent operations.
Start pushbuttons should be above or to the left of stop buttons.
Emergency stops must be accessible and operable at each control station.

NFPA 79 Control Equipment: Location, Mounting & Enclosures

Equipment should be easily accessible for maintenance and operation.
Protective constructions must align with UL standards (e.g., UL 508, UL 508A, NEMA 250).
Minimum enclosure protection is Type 1.
Working spaces in front of control cabinets must be at least 762 mm (30 in).

Wiring Practices

All wire connections need securing against accidental loosening.
Proper identification is required for connections based on the conductor's type and area.
Shields on conductors should prevent fraying and allow easy disconnection.
Tags must be permanent and legible.
Terminal blocks must be configured to prevent crossover wiring.

Conductors & Cable Requirements

Conductors must be insulated and made of copper.
Insulation should be flame retardant.
Conductors are color-coded for identification (e.g., green for ground, black for ungrounded).

OSH Act and OSHA Overview

Passed in 1970 to protect workers from workplace hazards.
OSHA enforces and sets safety standards under the US Department of Labor.
General Duty Clause requires employers to maintain a hazard-free workplace.

Responsibilities Under OSHA

Suppliers: Ensure machines are designed for effective hazard control.
Users: Ought to establish protective programs against hazardous energy.
Personnel: Must follow the hazardous energy control programs.

Case Studies

Secretary v Loren Cook: Highlighted compliance issues regarding machine guarding; defense of infeasibility established.
Secretary v Walmart: Focused on workplace accidents and penalties for safety violations.

Risk Management Terminology

Risk Reduction: Actions taken to minimize potential hazards.
Acceptable Risk: Level of risk deemed manageable and justifiable.
Lockout/Tagout: Procedures to prevent the accidental energization of machinery, crucial for safety in handling hazardous energy.

Learning Objectives

Cover essential topics including conductors, wiring practices, electric motors, and safety regulations in relation to NFPA 79 standards.

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Description

Test your knowledge of the key definitions and mandatory requirements outlined in NFPA 79. This quiz covers applications, compliance with existing machinery, and important regulatory clauses. Perfect for those studying electrical standards and safety guidelines.