1. Changes to Part 4 – Work Rules
2017 NESC
Changes to Part 4 – Work Rules
Presented to
Quad-State Instructors, Inc.
January 12, 2016
Columbus, Ohio

2. Proposed Changes

3. OSHA Impacts CPs reviewed Sept/Oct 2013
Revised / 1926 Subpart V Issued April 11, 2014
Arc Flash
Fall Protection
MADs
NESC Preprint to be finalized June 1st, 2014
SC8 teleconference created new revised comments to bring Part 4 into conformance with OSHA
Combine original CPs, RCs and comments into final revisions

4. Semantics Numerous changes proposed Almost all rejected or withdrawn
“in the vicinity of…” to “on or near…”
“protect life and property…” to protect persons and property…”

5. Arc Flash – Rule 410 A3 Revised to match OSHA rules When PPE required
What is “clothing”
Restrictions on materials

6. Table 410-1
Footnote 4:
Testing was only done on 200A style 16S single socket meters only.
400A style 320-A and multi-meter panels will have higher heat flux rates and will not self-extinguish similar to larger power panels, arc analysis required.
Tuscon Electric currently doing testing
No CP was received on this so cannot make revision to 2017 code, a TIA will be issued instead

7. Table 410-1
Footnote 11:
Arcs will not self-extinguish when associated transformer is energized. When network protector is open and associated transformer is de-energized, arcs will self-extinguish in under 6 cycles; 8 cal/cm2 clothing recommended
Again, no CP received so TIA will be issued

8. Table 410-1
Recent OSHA LOI indicated they would accept values in Table EXCEPT for those values not based on testing.
There actually was testing on 480V open air conductors, data was just not given to SC8
Actual testing showed heat values of 3 cal/cm2 so table value is valid.

9. EPRI All 3 changes discussed are explained FREE download from EPRI!
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10. 410 A3b New exception for low voltage DC
For DC systems with voltages from 50 V to 250 V and 8000 amps maximum fault current, in lieu of performing an arc hazard analysis, clothing with a minimum effective arc rating of 5 cal/cm2 shall be used.

11. 411 Protective methods and devices
B Devices and equipment
4. Protective goggles Face and eye protection

12. 411 D Signs and tags for employee safety
Safety signs and tags required by Part 4, when installed or replaced, shall comply with the current edition of ANSI Z535.1 through ANSI Z535.5

13. 420 G Liquid-cell batteries
Rejected a CP to do major rewrite of this rule
Forming a working group with SC3 to rewrite for submission to code cycle.

14. 420 K Fall Protection
Revised to match new OSHA fall protection rules in and Subpart V

15. 422 A Setting, moving, or removing poles in or in the vicinity of near energized electric supply lines
1. When setting, moving, or removing poles in or in the vicinity of energized lines, precautions shall be taken to avoid direct contact of the pole with the energized conductors. Employees shall wear suitable insulating gloves or use other suitable means where voltages may exceed rating of gloves in when handling poles where energized conductors energized at potentials above 750 V can be contacted. Employees performing such work shall not contact the pole with uninsulated parts of their bodies.

16. 441 Energized conductors or parts
A. Minimum approach distance
1.a. The line or part is de-energized and grounded per Rule 444D
EXCEPTION: For voltages less than 600 V, where the making of the ground is impractical, the line or part may be isolated in lieu of installing temporary protective grounds provided the following conditions are met: (a) the lines and equipment are isolated from all sources and tested to be de-energized, (b) there is no possibility of contact with another energized source, and (c) the hazard of induced voltage is not present.

17. 441 Energized conductors or parts
A. Minimum approach distance
1. c. The energized line or part is insulated line or part is insulated from the employee and from any other line or part at a different voltage. Insulated line and parts include those covered with suitable insulation and having metallic shield, sheath, or concentric neutral or semiconducting shield in combination with suitable metallic drainage bonded to an effective bond.

18. 441 Energized conductors or parts
Notes at end of 441 A 1 revised
Reference to ANSI 516 replaced with reference to 29CFR Appendix B.
Note 4 now reads For the purpose of Section 44, “reach” is defined as the range of anticipated motion of an employee while performing a task, and “extended reach” is defined as the range of anticipated motion of a conductive object being held by an employee while performing a task.

19. 441 Energized conductors or parts
A Minimum approach distance
3. Precautions for approach – Voltages from 301 V to 72.5 kV
a. When exposed grounded lines, conductors, or parts are in the work area, they shall be guarded or insulated.
EXCEPTION: When work is being performed on parts energized between 300 V and 750 V within equipment enclosures, (e.g. control panels and relay cabinets), insulating or guarding of all exposed grounded lines, conductors, or parts in the work area is not required provided that employees use insulated tools and/or gloves and that exposed grounded lines, conductors and parts are covered to the extent feasible.

20. 441 Energized conductors or parts
A. Minimum approach distance
4. Precautions for approach – Voltages above 72.5 kV
Entire rule replaced with:
When performing live line work, employees shall position themselves so that they are not within the reach or extended reach of the applicable minimum approach distance.
In lieu of using the minimum approach distances in Table 441.1, the minimum approach distance in Tables through may be used provided the per unit transient overvoltage value (T) has been determined through an engineering analysis considering the system design, expected operating conditions, and control measures.

21. 441 Energized conductors or parts
Table AC live work minimum approach distance
Revised values in table to match new OSHA MADs in
Footnote 7 change reference from IEEE 516 to 29CFR Appendix B.

22. 441 Energized conductors or parts
Tables to 4 Minimum approach distance tables for transmission voltages
Revised to match new OSHA MAD values
Tables for distances in feet were left in ft-in format instead of decimal ft format as used by OSHA

23. 444 De-energizing equipment or lines to protect employees
C. Operating switches, disconnectors, open points and tagging
2. Air gaps created (e.g. cut or open jumpers) for de-energizing equipment or lines for the purpose of protecting employees shall be tagged and meet minimum clearances as specified in Table or separated by a properly rated insulator.

24. Table 444-1 Minimum Clearances for Open Air Gap

25. 2022 NESC NRECA Representatives on SC8:
Principal – Jonathan D. Cox; Northcentral Mississippi EPA
Alternate – Robert Harris; NRECA