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Energized Work Permit - Battery Systems
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Author:  charlb28 [ Mon Feb 24, 2020 1:54 pm ]
Post subject:  Energized Work Permit - Battery Systems
What are your thoughts on EWP for batteries? Should an EWP be used to work on series connected batteries for use in UPS systems and 125VDC control of substation equipment?

On one hand, there is no exemption listed in 130.2 (B)(3) directly for batteries connected in series. Also there is no mention of an EWP in Article 320. So I can conclude that if the nominal voltage of the series connected string is >50V, an EWP is required.

On the other hand, there is no possible way to de-energize batteries when an electrician is working directly on them, either performing a PM or making inter-cell connections. An EWP is supposed to cause management or the electrician to state why the voltage cannot be removed. Obviously dealing with batteries, the voltage cannot be removed. So why would an EWP be required if it is not possible to de-energize?

I can see both sides to this argument, and my answer to this question asked of me was an EWP IS required based on current language. But I also see the argument that "why do I need an EWP when it is impossible to de-energize. It kind of waters down the need for an EWP.
Author:  jmkengineering [ Fri Jul 24, 2020 12:59 pm ]
Post subject:  Re: Energized Work Permit - Battery Systems
Here's my thought, it depends on the work.

Normal maintenance and measurements

If the work is being performed is a standard task, something that is routine and happens on a regular basis, develop a standard work procedure (SWP) and attach that to the work order.

When developing the SWP make sure that all the people that would normally sign an Energized Electrical Work Permit (EEWP) are involved and sign on it.

Then you have a document with a procedure that allows the worker to safely do the energized work.

Out of the ordinary or very infrequent work
If during the SWP the worker comes across something that is non-typical then they can stop work and re-evaulate, and an EEWP can be developed.

This is also the procedure that I recommend when you are doing infrequent work.

charlb28 wrote:
But I also see the argument that "why do I need an EWP when it is impossible to de-energize. It kind of waters down the need for an EWP.

I don't think using a EEWP on battery systems, that can't be de-energized is watering down the EEWP. An EEWP as a tool to allow everyone to step back and ensure that all hazards are controlled/managed in a manner that will allow the worker to work safely.
Author:  Terry Becker [ Mon Nov 09, 2020 7:44 am ]
Post subject:  Re: Energized Work Permit - Battery Systems
The employer's Electrical Safety Program documents additional exemptions related to the Energized Electrical Work Permit, justification, infeasibility. We do not need bureaucracy with no value.
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