PPE for operating a breaker

[RHJohnson]

I've seen many 480 VAC breakers that were closed on a direct short, but did not see arc blowing out all the crevices/openings around the breaker. I couldn't see through the closed cover. And - the breaker did not fail, they were still good.
I saw a flash of fire from the j-box on a 200 hp 2300 VAC motor. I opened the power & control circuits and then opened the j-box- saw nothing...Got a megger and checked, still good. Put back on line and started it up - it ran fine. Called the electrical superintendent, who was on the surface - I was down in the mine, and he said there was a thunderstorm with lots of lightning.
No damage was done to pump motor or controls, or cable..
One time called to check out an old "Compensating Starter", (old style oil filled starter from the 1920's) This was another 2300vac starter for a 100 hp air compressor (compressor type from early 1940's). You would manually move the start lever to the run position, when the motor got up to speed you would pull the handle back through the off position to the run position, where it would latch into place.
When I got there I could see the front cover bellied out between the bolts fastening it in place (cover about 4' tall and 18'' wide with about 6 bolts holding it in place down each side - open top and bottom, oil tank behind the cover). OL relay mounted eye level, middle of cover was broken due to the bulge in the cover. Checked everything this time also, even dropping the oil tank and checking contacts for both start and run - still nothing wrong.
My opinion was someone attempted to start the compressor without unloading it, which had to be done manually before starting. Nobody ever admitted to being the one who was starting it - I think they must have stained their shorts, and just wanted to keep it quiet.
My fellow electrician and I got a long rope, fastened the middle of the rope around the handle, and got on opposite sides, each of us 15' from the front of that starter. He pulled on the rope and the handle moved to the start position, when it got up to speed I pulled my end of the rope and the handle moved and latched in run. It ran just fine ..... we did change it out a few days later with another oil starter, this one from the 1950's with remote start!
This old equipment was still in use in the 1980's. We had equipment going back to the 19-teens. Had GE & Westinghouse parts catalogs from 1918.
Had battery operated electric locomotives from 1913. And had lots of control boards with all exposed wiring and contacts, etc. That old stuff was fun to work on, and would last forever..

 

[brian john]

RH: I am not sure what your point is?

I know I am easy but I DEFINITELY am not cheap.

This is what we call self applied, the electrician that is going to close the CB, uses HIS megger to check the circuit.

 

[tobacmon]

I have this same problem and the unqualified personnel are opening 277/480 dimmer & lighting panels that have override switches in them and are pushing them to pull in lighting.

I have heard or read somewhere that personal were having problems with a breaker staying in and kept throwing on & off until it held without checking to find the actual cause of the fault--downstream it was a maintenance man trying to plug in a pump when it shorted causing the fault. So every time the breaker was energized oh boy downstream was getting hit.

With the breakers, my understanding is that only Qualified Personal are to open or close any breaker. (Qualified meaning license by the state) I personally do not have a problem with this as long as it does not come back to bite me in the butt---I do post a question though--Why do they have marked on every gear room Authorized personnel Only--Instead of Qualified. I heard they were to be changing this..

 

[zog]

I have this same problem and the unqualified personnel are opening 277/480 dimmer & lighting panels that have override switches in them and are pushing them to pull in lighting.

I have heard or read somewhere that personal were having problems with a breaker staying in and kept throwing on & off until it held without checking to find the actual cause of the fault--downstream it was a maintenance man trying to plug in a pump when it shorted causing the fault. So every time the breaker was energized oh boy downstream was getting hit.

With the breakers, my understanding is that only Qualified Personal are to open or close any breaker. (Qualified meaning license by the state) I personally do not have a problem with this as long as it does not come back to bite me in the butt---I do post a question though--Why do they have marked on every gear room Authorized personnel Only--Instead of Qualified. I heard they were to be changing this..

Qualified by the state? I think you have been mislead here, an electrical license has nothing to do with who is qualified to operate circuit breakers or access panels.

You need to look at the definition of a "Qualified person" in either the NFPA 70E or OSHA 1910.333

 

[brian john]

Qualified meaning license by the state

Not every state has licensing.

Why do they have marked on every gear room Authorized personnel Only--Instead of Qualified. I heard they were to be changing this..

Authorized? qualified?, what makes you think because an electrician has a license he is qualified or authorized. Some of the most dangerous electrical practices are performed by licensed electricians.

Authorized also includes permission from management not every licensed person may have permission to enter.

 

[shockin]

No one in this forum can tell you if that task is HRC 0 or otherwise.

I understand that in the unrealisitc world of OSHA a complete flash hazard analysis must be performed prior to even think about operating a single pole 20 amp breaker.

In the real world we use a conserative chart for task such as these. My cheater chart shows an HRC of 0 for this task if the panel is less then 240 volts, the covers are in place, and the AIC is assumed to be less then 25kA.

If the AIC is less then 10kA then the HRC goes down to negative one. However the task would still require natural fiber short sleeved shirt and pants, hard hat, safty glasses and leather safty shoes.

How do you go about determining the approporiate level of PPE. Do you actually perform the complete analysis prior to each task?

 

[zog]

I understand that in the unrealisitc world of OSHA a complete flash hazard analysis must be performed prior to even think about operating a single pole 20 amp breaker. ?

No such requirement exists (In either world)

In the real world we use a conserative chart for task such as these. My cheater chart shows an HRC of 0 for this task if the panel is less then 240 volts, the covers are in place, and the AIC is assumed to be less then 25kA. ?

Exactly, you need to know the available fault current (Not AIC) and the clearing time of the upstream protective device to use the tables, if the system you are working on does not meet the assumptions of the tables the tables are invalid and will not offer adequete protection.

If the AIC is less then 10kA then the HRC goes down to negative one. However the task would still require natural fiber short sleeved shirt and pants, hard hat, safty glasses and leather safty shoes.?

This is being removed from the next 70E revision, it has been misused and abused.

How do you go about determining the approporiate level of PPE. Do you actually perform the complete analysis prior to each task?

No, unless the plant I am working at has done an analysis. Otherwise I use the same tables as you do.

 

[brian john]

No such requirement exists (In either world)

How do you know what world I live in. On Zeta 3 this is the LAW.

 

[quogueelectric]

I have seen sparks come shooting out from 120v recepts as well.

If this is such a safety concern, even with dead front and covers in place, then ALL electrical panels, disconnects, and service equipment should be encapsulated in lead vaults locked away from anyone who is not an electrician wearing PPE.

Panel covers and dead fronts are designed for two reasons.
1- to protect people from coming into contact with energised parts
2- to reasonably contain a blast from a fault

I have seen flames shoot out from crevasses and seams in a panel, and while it does get your attention, it (IMO) still is a safe situation and not an immediate hazard.

If the equipment does not do its job and clear the fault you have a serious problem on your hands and I have witnessed that also the concrete was burning at one point. If you have ever seen both a 480 short and a 120v short close and personal you would not even entertain saying something like that.

 

[cadpoint]

In the past it has been common for us to use switch rated breakers as the only control for the lights in a factory. The get turned on and off once a day. As I read NFPA 70e if looks like this daily task would actually require a HRC of O. I assume this standard applies to the factory employees that operate the breaker and not just the electrician. Any thoughts?

My order of answers to your thread:

1. I do care why the NEC places a zone in front its equipment. I believe a lot of people don't understand this Zone around electrical equipment.

2. I don't believe it should be that anyone in the plant can go flick the lights!

3. I've never read NFPA 70e.
My personal thoughts are that a panel with circuits is a means of disconnect but is not to be used in a public manner as described.
And yes I've seen people in plants throw circuits and disconnects because their machine didn't have power!

The first thing after my first reply was to re-read back on the OP post to read of a switch rated breaker, and yes I frankly missed that, "So What", was my next thought.

Put the circuit on a time clock or give them a bank of switches and keep your panels locked.