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 Post subject: AF Labels on Disconnects?
PostPosted: Thu Oct 17, 2019 7:15 am 

Joined: Tue Dec 02, 2014 7:46 am
Posts: 14
We were affixing 4x4 AF Warning labels on 480 & 208 Volts disconnects with descriptions of AF PPE requirement and Shock protection boundaries limits. Then contractors start installing smaller
sizes disconnects where is no place to affix a label.

Then I went back to look NEC & 70E, none of them require arc flash warning labels on disconnects. So I think affixing arc flash label on disconnect is not a requirement.

I want to know if other members of ArcFlashForum are agreeing with me. Thank you


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 Post subject: Re: AF Labels on Disconnects?
PostPosted: Thu Oct 17, 2019 2:15 pm 
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Joined: Wed May 07, 2008 5:00 pm
Posts: 819
Location: Rutland, VT
What NFPA 70E-2018 Art. 130.5(H) says is electrical equipment such as and lists some examples but is not a definitive list and goes on with the statement "...likely to require examination, adjustment, servicing or maintenance while energized shall be marked with a label....."

If the disconnect switch is a fused switch, is it not possible that it could be opened to verify if a fuse is blown or take voltage and current measurements? Is it not possible that the disconnect switch would be the point to verify de-energization for LOTO? All of these tasks would require AR PPE, so without a label, how does the employee know what the incident energy level is to be able to choose the proper AR PPE?

So yes, I do label disconnect switches, both fused and non-fused. If the label is too big for the switch, the label will go on the wall if possible or in a vinyl pouch tywrapped to the conduit into the switch.

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Barry Donovan, P.E.
www.workplacesafetysolutions.com


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 Post subject: Re: AF Labels on Disconnects?
PostPosted: Mon Oct 21, 2019 6:11 am 
Sparks Level

Joined: Tue Jul 01, 2014 8:40 am
Posts: 89
Hello Sheel, My question is, why are you inserting AF PPE, etc on the warning label. Too much information that is not even required. Also you are increasing your liability when inserting all of this information


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 Post subject: Re: AF Labels on Disconnects?
PostPosted: Tue Oct 22, 2019 9:07 am 
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Joined: Tue Jan 19, 2010 2:35 pm
Posts: 132
To me, there is no question: you must label fused disconnects. Here's why I think that. If you think about the intent behind NFPA 70E, you will see it's driven by the OSHA requirement that employers must identify workplace hazards. Why identify those hazards if not to inform the worker of the hazards? Why tell them about the hazards other to protect themselves. But with arc flash and shock hazard, the employer must also quantify the hazard so the worker knows exactly what level PPE is needed and where he needs to establish the arc flash and shock hazard boundaries. With fused disconnects, it's clear that any trouble shooting exposes the worker to both arc flash and shock hazard. That exposure triggers the need for arc flash and shock hazard labeling.


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 Post subject: Re: AF Labels on Disconnects?
PostPosted: Mon Oct 28, 2019 8:09 am 
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Joined: Tue Oct 26, 2010 5:00 pm
Posts: 186
Location: Maple Valley, WA.
Many of our clients do not want to pay for AF labels on all disconnects. So as a compromise, we will provide labels for fused disconnects but not for no load or isolating (for LOTO) disconnect switches. We also inform the client that if the door or cover of a non fused disconnect is to be opened and there is no AF label, then go upstream to the location where it is being fed and use the AF label shown. This is usually a conservative method as the AF energy is usually higher has you go upstream in the distribution system.

The exception to this is at transformer secondaries. At these locations, the primary protective device provides the protection for the secondary side. Due to the physics of the transformer (Impedance and lower primary current for a fault on the secondary side), the primary device provides very poor protection for the secondary side.

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Robert Fuhr, P.E.; P.Eng.
PowerStudies


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 Post subject: Re: AF Labels on Disconnects?
PostPosted: Tue Oct 29, 2019 6:33 am 

Joined: Tue Oct 29, 2019 6:23 am
Posts: 19
I would support Mr. Fuhr position. Important to understand that the label must represent the AF hazard the worker may be exposed to when the cover/door/panel is open. Generally, that is the line side of the device, not the secondary side, and "if" that protection is provided by an OCPD on the HV side of a transformer that protection has a low probability of being good AF protection to the secondary side unless it was specifically selected and set properly for that purpose.

It is my understanding the AF label could display a value of incident energy, or a PPE requirement. The point is that the data make sense and be useful to the qualified individuals that will need to use the information.


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