Safety Standard No. E-84 Electrical Clearing Procedures © 2001 by The Dow Chemical Company This document and all content are copyrighted material. All

Safety Standard No. E-84 Electrical Clearing Procedures

© 2001 by The Dow Chemical CompanyThis document and all content are copyrighted material. All rights reserved

Dow ConfidentialNo part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means — electronic, mechanical,

photocopying, recording, or otherwise — without prior written permission from The Dow Chemical Company.

Training Course

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Safety Standard No. E-84 Course Map

Course Information & Objectives

Lesson 1: Scope and DefinitionsScopeDefinitionsReview Questions & Summary

Lesson 2: Requirements & ContentRequirements - Equipment and CircuitryRequirements - Electrical Clearing Procedures Approval and ReviewReview QuestionsContent of Electrical Clearing Procedures Review Questions & Summary

E-84 Course Wrap Up

Post Test

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Course Information

Target Audience

Equipment Owners & Plant Personnel

Owners and Holders of Electrical Safe Work Permits (ESWP’s)

Course Knowledge Level

Fully competent upon completion of this course.

Time Required to Complete the Course

30 minutes

Course Description

This is a self-paced course on Safety Standard No. E-84. This course is not intended to be the sole preparation for clearing electrical equipment. Familiarity with your electrical equipment and some hands-on training will be necessary. Contact your local Training Coordinator to arrange hands-on training.

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Course Objectives

After completing this course, you will be able to:

Recognize the scope of where E-84 applies.

Identify the definitions of electrical clearing terms.

List the requirements for electrical clearing procedures.

Describe the typical content of electrical clearing procedures.

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Lesson 1: Scope and Definition

Lesson 1 defines the scope of Safety Standard E-84 and defines terms involved in the safe clearing of electrical equipment. After completing this lesson, you will be able to:

Recognize the kind of work where E-84 requires an electrical clearing procedure.

Define the terms used in discussing electrical clearing.

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Lesson 1: Scope

Safety Standard E-84 governs the electrical clearing procedures to be used for all work on de-energized electrical equipment operating above 300V AC or DC.

Typical examples of equipment requiring an electrical clearing procedure would be process pump motor controllers, transformers for lighting and power, distribution system circuit breakers and high voltage switchgear.

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Lesson 1: Definitions

Clearing:

The method and means for establishing, verifying and maintaining the de-energized status of electrical circuits and equipment.

How are you going to make sure the circuitry and equipment are de-energized before starting any work?

How will you make sure the circuits and equipment remain de-energized while the work is in progress?

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De-energized:

Essentially zero volts as verified by voltage checks with approved voltmeters per EWP-32.

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Cleared for Electrical WorkCircuits and equipment shall be designated as cleared for electrical work only after their de-energized status has been:

Assured by voltage checks per EWP-30

And…

Verified by visible air gap and/or applied protective grounds per EWP-33 w/Freeport Additions

And…

Maintained by Lockout/Tagout

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Visible Air Gap:

Physical circuit separation sufficient for the operating voltage involved to maintain a de-energized status.

Sufficient physical circuit separation is provided by the circuit disconnecting means, but not all disconnecting means provide an adequate way of verifying that a visual air gap exists, such as molded case circuit breakers

LO/TO: LO/TO (Lockout Tagout) shall be applied per 06.05C Isolation of Energy Sources (RedTag) Standard with Freeport Additions.

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Lesson 1: Definitions – Visible Air Gap, continued

If an adequate visible air gap cannot be established, then circuit grounds must be applied to all phase conductors.

Whenever one side or the other of a disconnecting means is not completely visible, so you can ensure that an air gap does in fact exist, then additional measures must be taken.

Typically these measures would include:• removal of circuit fuses & links• physically disconnecting circuit wiring

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Lesson 1: Definitions – Equipment Owner

The equipment owner is the representative designated by the business or department to be responsible for the safe operation of the equipment.

For operating plants, this role is designated by the Production Leader, and would typically be plant operating personnel or plant process technicians.

For construction projects this role would typically be filled by the Owner’s Representative.

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Electrical Instructed or Electrical Skilled Person:

A person Certified by the businesses per 06.05.C.03 Electrical Safe Work Standard to be, by combined level of training and experience at the applicable voltage level, adequately familiar with the construction and operation of the equipment, the hazards involved, and the current standards and procedures in effect designed to minimize or eliminate those hazards.

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The Safety Electrical One-Line Diagram or SEOLD is a single-line diagram of the power distribution system within a clearly defined operating area. It is used for operating and clearing purposes.

Safety Electrical One-line Diagrams are normally posted in switch rooms adjacent to the equipment represented on the drawings.

SEOLD’s illustrate the power flow in the electrical distribution system and are used to determine the proper disconnecting device(s) that must be opened for clearing equipment or circuitry.

Safety Electrical One-line Diagrams are governed by Safety Standard E-83.

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An Isolating Device is:A single device, as shown on the SEOLD, providing a visible air gap, or

A Visible air gap created by circuit separation sufficient for the voltage.

Protective Grounds:Personal Protective Grounds or Temporary Grounds per EWP-33 w/Freeport Additions

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Lesson 1: Definitions – Auxiliary Circuit

An auxiliary circuit is any circuit operating at or above 50 v (AC/DC) that is derived from a source outside of the motor controller or breaker enclosure, and that is not controlled by the controller or breaker’s Isolating Device.

Typical Auxiliary Circuits:• Motor space heaters fed from low voltage lighting panels that are switched on when the

motor contactor or breaker is opened. In this circuit the space heater auxiliary voltage remains energized after the motor Isolating Device is open.

• D.C trip voltage for circuit breakers is typically derived from a battery bank which remains energized after the Isolating Device (breaker or disconnect) has been opened.

Example: any circuit at or above 50VAC/DC present within the controller or breaker that remains energized after the Isolating Device has been opened, such as motor heaters, alarm circuits, test power circuits, etc.

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Generic Procedure: A generic procedure is one that DOES NOT require the naming of specific pieces of equipment/valve numbers/Mod addresses. It is a procedure that applies to a category or group of equipment. In order for a procedure to be generic, all procedure steps, hazards, precautions, PPE, etc. must be the same for all equipment in the scope.

Combined Procedure: A combined procedure is one that DOES require the naming of specific pieces of equipment/valve numbers/Mod addresses. In order for a procedure to be combined, all procedure steps, hazards, precautions, PPE, etc. must be the same for all equipment in the scope.

Specific Procedure: A specific procedure is one that names the specific piece of equipment/valve numbers/Mod addresses with specific hazards associated with the procedure. This procedure contains something unique or is complicated enough that it cannot be easily combined with another procedure.

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Selecting a procedure type:

If the procedure applies to a category or group of equipment, such as all exhaust blowers in a building, or all sump pumps in an area, and all procedure steps, hazards, precautions & PPE are the same, then the use of a Generic Procedure is preferred. Generic procedures do not require that each piece of equipment in the procedure scope be included in the procedure.

If the procedure doesn’t apply to a category or group of equipment, but it does apply to several pieces of equipment , such as Exhaust Blower 1, Exhaust Blower 2 & Sump Pump 3, and all procedure steps, hazards, precautions & PPE are the same, then the use of a Combined Procedure is preferred. Combined procedures do require that the name of each piece of equipment in the procedure scope be included in the procedure.

If the procedure only applies to one piece of equipment, then a Specific Procedure is required. Specific procedures require that the specific equipment name be included in the procedure.

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Lesson 1: Review

Select the correct answer to complete the sentence.

E-84 governs the electrical clearing procedures to be used for _____.

a) All work on electrically driven mechanical equipment.

b) All work on 120V powered instruments.

c) All work on de-energized electrical equipment operating above 300 volts AC or DC.

d) All work on any electrical equipment.

Select the True statements about Procedures types:

a. A Generic Procedure does not require naming specific pieces of equipment.

b. Specific Procedures are required for all electrical clearing.

c. A Combined Procedure does require naming specific pieces of equipment.

d. A Specific Procedure names the specific piece of equipment.

NO

NO

YES

NO

TRUE

TRUE

TRUE

FALSE

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The method and means for establishing, verifying and maintaining the de-energized status of electrical circuits and equipment.

Clearing

Essentially zero volts as verified by voltage checks with approved voltmeters per EWP-32

De-Energized

The de-energized status is assured by voltage checks per EWP-30, verified by visible air gap and/or applied protective grounds per EWP-33 w/Freeport Additions, and maintained by Lockout/Tagout.

Cleared for Electrical Work

Name the terms described by the following definitions:

Lesson 1: Review

Physical circuit separation sufficient for the operating voltage involved to maintain a de-energized status.

Visible Air Gap

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A single device, as shown on the SEOLD, providing a visible air gap, or a visible air gap created by circuit separation sufficient for the voltage.

Any circuit operating at or above 50VAC/DC that is derived from a source outside of the motor controller or breaker enclosure, and that is not controlled by the controller or breaker’s Isolating Device.

Personal Protective Grounds or Temporary Grounds per EWP-33 w/Freeport Additions

Auxiliary Circuit

Isolating Device

Protective Grounds

Lesson 1: Review

Name the terms described by the following definitions (continued):

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Lesson 1: Summary

In Lesson 1 you learned:

Safety Standard E-84 covers the electrical clearing procedures to be used for all work on de-energized electrical equipment operating at or above 300 volts AC or DC.

The definitions of terms commonly used in electrical clearing procedures.

Lesson 2 will cover the Requirements and Content of electrical clearing procedures.

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Lesson 2: Requirements of Electrical Clearing Procedures

Lesson 2 describes when an electrical clearing procedure is needed and what is required in an electrical clearing procedure. After completing this lesson, you will be able to:

Recognize the type of equipment and circuits that must have electrical clearing procedures.

Identify the requirements for creating, approving and revising electrical clearing procedures.

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Equipment and circuitry not yet connected to its source of plant or utility power is not subject to the requirements of E-84.

Equipment and circuitry SHALL be subject to the requirements of E-84 while being connected to its source of plant or utility power and there after.

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Two Electrical Skilled Persons are required to validate the content and accuracy of electrical clearing procedures for equipment operating above 600V.

Two Electrical Skilled Persons, or one Electrical Instructed and one Electrical Skilled Person, are required to validate the content and accuracy of electrical clearing procedures for equipment operating above 300V up through 600V.

Either a Combined or Specific procedure is required to clear electrical equipment and circuitry fed by multiple sources, designed to provide power to the load at the utilization level.

Either a Generic, Combined or Specific procedure is required to clear electrical equipment and circuitry fed by a single source, designed to provide power to the load at the utilization level.

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The matrix below summarizes the minimum requirements for selecting the type of procedure to be used, and the personnel qualifications required to validate and execute the selected procedure.

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Lesson 2: Review

Question 1

Match each description to its correct Requirement.

Two Electrical Skilled Persons

Required to validate the content and accuracy of electrical clearing procedures for equipment operating above 600V

Two Electrical Skilled Persons, orOne Electrical Instructed and one Electrical Skilled Person

Required to validate the content and accuracy of electrical clearing procedures for equipment operating above 300V up through 600V

Equipment being connected to its source of plant or utility power

Subject to the requirements of E-84.

Combined or Specific Procedure

Required to clear electrical equipment and circuitry fed by multiple sources.

Generic, Combined or Specific Procedure

Required to clear electrical equipment and circuitry fed by a single source.

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Lesson 2: Content of Electrical Clearing Procedures

Generic, Combined and Specific Clearing Procedures covering electrical work on equipment, circuits and/or circuit conductors shall include, but not be limited to:

The category or group of equipment in Generic Procedures.

The specific pieces of equipment in Combined Procedures.

The specific piece of equipment in Specific Procedures.

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Lesson 2: Content of Electrical Clearing Procedures (cont’d)

The boundaries of equipment and circuitry cleared.

Boundaries describe the limits of circuitry that is safe to touch.

Typical examples would be:

“Circuit cleared from the load side of MP-201 Main Disconnect to the motor.” or “Bus A cleared from load side of Bus A Main Breaker to Bus A side of Tie Breaker.”

A description of the Hazards involved.

Typical hazards would be “Eye injury from arcing,” “Burns from arc flash,” & “Shock from exposed energized conductors.”

A description of Tools to be used.

A description of personal protective equipment required.

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A description, as required, of special precautionary instructions and techniques to be used.

These may include specific mechanical issues associated with clearing equipment.

The number and qualifications of person(s) required to execute the procedure.

Do they need to be Electrical Instructed or Electrical Skilled Persons

Review of the current applicable Safety Electrical One-Line Diagram (SEOLD).

The boundaries of cleared circuitry may extend over several SEOLDs… all must be reviewed.

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Placement of Owner and Holder Lockout/Tagout.

A positive means of providing and verifying isolation by visible air gap and/or protective grounds on all isolating devices.

Examples: Open disconnect, removed fuses, breaker rolled out of its compartment or application of PPGs or TGs.

The need to remove fuses and/or links, as required.

Description of voltage tests to verify the de-energized status of the equipment or circuit.

Should include the equipment , its location and location on the circuitry where voltage tests should be made.

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The identification of Auxiliary Circuits present in the equipment, as required.

Typical Aux Ckts are for motor heaters, oil pumps and aux control power.

A means to safely manage auxiliary circuits, as required.

Will they need to be isolated or require LO/TO be applied.

Sketches, pictures and/or illustrations as required describing unique equipment features and any other items needed to perform the work safely.

Whenever it provides a more positive description, the use of a sketches, & photos are recommended.

Instructions for notifying the Power Dispatcher if required.

As needed for equipment controlled by the Dispatcher.

The Power Dispatcher phone number is 979-238-2575

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Lesson 2: Review

Select True or False about electrical clearing procedures.a. Equipment and circuitry designed to operate above 300 V AC or DC must have an electrical clearing

procedure when it is being connected to its source of plant or utility power.

b. Electrical clearing procedures for 480V equipment must be Validated by a minimum of one Electrical

Instructed and one Electrical Skilled Person.

c. Electrical clearing procedures for 480V equipment requiring an ECT can be executed by one Electrical

Instructed Person.

d. Electrical clearing procedures for 480V equipment requiring an ESWP must be executed by a

minimum of two Electrical Instructed Persons. TRUE

TRUE

TRUE

TRUE

Electrical Clearing Procedures must contain: a. The boundaries of equipment and circuitry cleared.

b. A description of hazards involved.

c. A means for updating the SEOLD.

d. A positive means of providing isolation by visible air gap and/or protective grounds on all

isolating devices.

e. A review of the current applicable SEOLD.

CORRECTCORRECT

CORRECTCORRECT

INCORRECT

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Lesson 2: Review

Electrical Clearing Procedures must also include:

a. The identification of Auxiliary Circuits present in the equipment, as required.

b. The equipment manufacturer’s recommended auxiliary circuits.

c. A means to safely manage auxiliary circuits, as required.

d. A positive means of providing and verifying isolation by visible air gap and/or protective

grounds on all isolating devices.

e. A determination of the need to remove fuses and/or links, as required.

f. Description of the voltage tests to verify the de-energized status of the equipment or

circuit.

CORRECT

INCORRECT

CORRECT

CORRECT

CORRECT

CORRECT

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Resources

Additional information about electrical clearing is available through:

The Power Dispatcher at the Power Distribution Department, 979-238-2575.

Site Electrical Discipline Activity Specialist, DAS.

Your EH&S Delivery Leader.

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Lesson 2: Summary

In this lesson, you learned the Requirements and Content of electrical clearing procedures

Go to the Post Test

Documents

Safety Standard No. E-84 Electrical Clearing Procedures © 2001 by The Dow Chemical Company This document and all content are copyrighted material. All