resetting a 2000a main

[zog]

Are you telling me that you would call the power company before resetting a main breaker to de-energize the gear??

Not at all, in fact that would be a bad idea because the person they would send (If they even would) would not be qualified per the 70E or have the proper PPE, they follow the NESC which is a whole different world. I would do it myself because I am qualified and have trained thousands of people to do this task over the last 15 years.

I was simply responding to your post about never seeing this in switchgear instructions when it is the first thing in all of them and is in large bold print with danger symbols and a border all around it, wonder how someone would miss that.

 

[charlietuna]

I believe your refering to the labels located on the switchgear access panels?? I was refering to the instructions above the main breaker handle.. those that explain how to close and open the main breaker..

 

[zog]

I believe your refering to the labels located on the switchgear access panels?? I was refering to the instructions above the main breaker handle.. those that explain how to close and open the main breaker..

I am refering to the instalation and operating instruction book that comes with the switchgear.

 

[charlietuna]

The "operating instruction book" would be located in one of two places:
1) in the management office
2) inside the front cover over the main breaker requiring that you have "on" PPE protection clothing before opening. And the average security guard knows very little about PPE anything! I do not believe it is necessary or required to wear PPE clothing to close a 2000 amp main breaker at a condo...

 

[zog]

The "operating instruction book" would be located in one of two places:
1) in the management office
2) inside the front cover over the main breaker requiring that you have "on" PPE protection clothing before opening. And the average security guard knows very little about PPE anything!

you need to be familiar with the construction and safe operation of the equipment and know the proper use of the PPE necessary to be "qualified" to operate the equipment by 70E and OSHA definitions. The average security gaurd needs to be qualified also, being qualified to operate this equipment has nothing to do with being an electrician.

I do not believe it is necessary or required to wear PPE clothing to close a 2000 amp main breaker at a condo...

Well you are wrong, and with that attitude likely to become a statistic someday yourself. Sounds like you need some arc flash training. Have you seen this? http://www.youtube.com/watch?v=PHs14ZTo96M

Every year around 2,000 arc flash victims are sent to burn centers, ever been in a brun center? I have and it sucks.

 

[weressl]

Every year around 2,000 arc flash victims are sent to burn centers, ever been in a brun center? I have and it sucks.

Could you please post the source where this data is from?

 

[zog]

Could you please post the source where this data is from?

IEEE

http://standards.ieee.org/esrc/arcflash/arcFlash_projectProspectus.pdf

 

[weressl]

Actually when I calculate arc flash incident energy, I am assuming the protective devices will operate as intended. The PPE is for accidents, lapses in judgment, and other uncontrolled situations that may cause an arc to be developed.

The Coast Guard wears PFD's on small patrol craft not because they expect the craft to sink, but in case they end up in the water anyway.

The protective devices may operate as SET, not as intended. I was talking about bad design when selective coordination and fault level withstand is either ignored or the protective equipment does not sufficient to interrupt fault.

What irks me is that instead of attacking THAT problem and enforcing it on the OWNER's level, they go after the installer/repairer and allow them to be exposed to potential hazard just tell them to protect themselves. Again, I maintain that properly designed and maintained electrical systems will work with a high degree of relaibalility and safety presenting minimal exposure hazard to the employee.

 

[weressl]

IEEE

http://standards.ieee.org/esrc/arcflash/arcFlash_projectProspectus.pdf

There are statistics and there are damn lies.

"Over 2000 times a year, workers are admitted to burn centers for extended injury treatment."

That is true, however it does NOT state that all those injuries are due to arc-flas and indeed they are not. Nor does it even say that all those burns are the result of electrical incident. It doesn't, because they aren't. The whole arc-flash brouhaha is driven by zealotry not unlike global warming or even climate change caused by man's activity.

When you dig into he NBLS this becomes clear.

Follow the money.......​

 

[charlietuna]

Zog,
Thanks for the education--but the video shows someone racking out a main breaker---the original post was about a security guard reseting a main breaker with all the switchgear's panels in place. There seems to be some misconseption that before going into a switchgear room one must be wearing PPE ? Like any other electrical switch, switchgear is designed to withstand a fault without exposing the operator to a danger. Now i have seen exceptions to this myself -- but do not believe it necessary to wear PPE to close a main switch.......

 

[zog]

Zog,
There seems to be some misconseption that before going into a switchgear room one must be wearing PPE ?

No, but you do need PPE to interact with the equipment as defined in the 70E

Like any other electrical switch, switchgear is designed to withstand a fault without exposing the operator to a danger.

No it is not, that is a misconception, thats why they have the warnings. There is arc rated switchgear in the market but it is fairly new, but it must meet the requirements of IEEE C37.20.7-2007

 

[weressl]

No, but you do need PPE to interact with the equipment as defined in the 70E



No it is not, that is a misconception, thats why they have the warnings. There is arc rated switchgear in the market but it is fairly new, but it must meet the requirements of IEEE C37.20.7-2007

Not it is NOT a misconception. Electrical equipment are designed to interrupt full faults safely within their rating. They are tested and listed per the relevant third party NRTL's accordingly. Internal faults combined with either malfunctioning or maladjusted upstream protection will produce catasrtophic failures that MAY result in an arc-flash incident.

 

[brian john]

many times building engineers and maintenance people call me at all hours under pressure from upper management to reset tripped mains. I give them my stock response that I cannot recommend it. I also offer to come out, several times I have told them I would come for free IF THERE IS NO PROBLEM but if I find an issue it is billable (in all cases I have found an issue.

I stock bolted pressure switch parts as many times the switches are mis-operated and the closing mechanism suffers for this.

The deal is management feels these guys should be able to do this.

If they absolutely have to perform resetting I suggest.

Look for problems, with the power off look into the gear if they can SAFELY.
Open all downstream OCPs.
Set the GFP relay at 100 amps Instantaneous or .1 seconds (depending on relay manufacture).
Close the main then slowly one at a time close down stream switches if it trips again leave that OCP off and start over.

 

[zog]

Not it is NOT a misconception. Electrical equipment are designed to interrupt full faults safely within their rating. They are tested and listed per the relevant third party NRTL's accordingly. Internal faults combined with either malfunctioning or maladjusted upstream protection will produce catasrtophic failures that MAY result in an arc-flash incident.

I agree the equipment is designed to interupt the fault safely, but that is not what we are discussing here, we are discussing a fault in the equipment, and containing that arc is not part of the design criteria. Some gear has open vents, how is that supposed to contain an arc flash?

I have responded to many incidents where there was an internal arc and the gear did not contain it, so has Brian John, and I am sure many others here have as well.

Arc rated switchgear is designed for arc flash containment, but if it is not arc rated it may not.

 

[weressl]

I agree the equipment is designed to interupt the fault safely, but that is not what we are discussing here, we are discussing a fault in the equipment, and containing that arc is not part of the design criteria. Some gear has open vents, how is that supposed to contain an arc flash?

I have responded to many incidents where there was an internal arc and the gear did not contain it, so has Brian John, and I am sure many others here have as well.

Arc rated switchgear is designed for arc flash containment, but if it is not arc rated it may not.

I did not say to contain the overpressure developed due to a regular fault. I said that ordinary equipment is designed to withstand a fault with normaly operating upstream protective devices. The vent openings are primarily designed for air circulation to effect cooling, but it will also vent the fault products safely without danger to personel. (5-7 cyle interruption.) Overpressure beyond the design limits will cause structural failure that will expose the operator to injury.

Arc resistant equipment is designed to overcome faults that are NOT cleared by appropriately sized protective devices and will vent the arc products into a specially designed vent channel that is usually ducted to the outside.

 

[charlietuna]

Zog,
Sorry I don't buy that statement... the original post stated a member's brother-who is a security guard called him to tell him he closed a trip main at a condo he was assigned to. Now, i'm considering the many condos i have wired or worked for, and these buildings gear and basic operating proceedures. Most of these buildings having mains in the neighborhood of 1200 to 4000 amp main breakers--some with breakers and others with pringle switches--closed front switchgear --- and rated as "closed front" but having ventilated leuvers around the sides. Some with cable services, others with bus stabs! Operating voltage 208 volts. Most of these buildings-do not have a person educated in the electrical field as far as maintainance crews, they are cleaners and painters,some lawn care specialists. Security might be in house or possibly an outside contract. And when a main trips chances are they(above) will attempt to reclose a breaker -- if it trips they might then call the EC that services the building. The newer gear equiped with GFI trips will trip if a motor grounds out in the condensed water system-- and go off line--after resetting the GFI the gear comes back on line without a problem. I can recall a 2000 amp main that i close for the first time with a direct phase to ground fault in it -- Power company guy comes in to wire the vault and looks inside the open gear and say's A-B-C-Nuetral "right to left", then went back in the vault and wrote it on the wall without realizing he forgot to reverse it--vault was wire backwords. I don't know how much the vault transformer weighed --but it was bigger than a VW ! And it came up off the floor about six inches when i closed that breaker.. And as i recall it took a couple of seconds to trip--but it never blew up or caused a fire ball--- we let them switch their cables around and i closed it a second time---this time i had my eyes closed--i will admit that!!! And i agree with John Brian , pringle switches don't take a lot of abuse and are not designed for too many normal operations before problems start showing up--mechanical mainly. But the normal operation of closed front switchgear, which is what we are talking about does not require PPE to be worn!

 

[zog]

Zog,
I can recall a 2000 amp main that i close for the first time with a direct phase to ground fault in it -- Power company guy comes in to wire the vault and looks inside the open gear and say's A-B-C-Nuetral "right to left", then went back in the vault and wrote it on the wall without realizing he forgot to reverse it--vault was wire backwords. I don't know how much the vault transformer weighed --but it was bigger than a VW ! And it came up off the floor about six inches when i closed that breaker.. And as i recall it took a couple of seconds to trip--but it never blew up or caused a fire ball--- we let them switch their cables around and i closed it a second time---this time i had my eyes closed--i will admit that!!!

So your logic is that becase there was not an arc flash from this one instance that is cannot happen?

But the normal operation of closed front switchgear, which is what we are talking about does not require PPE to be worn!

Read the NFPA 70E, dont make your opionions sound like facts that can get someone else reading this injured or worse.

 

[zog]

Zog,
But the normal operation of closed front switchgear, which is what we are talking about does not require PPE to be worn!

This switch was closed into a fault, I could post examples like these all day.

 

[weressl]

So your logic is that becase there was not an arc flash from this one instance that is cannot happen?



Read the NFPA 70E, dont make your opionions sound like facts that can get someone else reading this injured or worse.

I agree Zog, reclosing a breaker after a fault is NOT to be considered as a normal operation. The tripping itself indicates the potential presence of an abnormal condition and without investigating it should not be reclosed. Investigating it should involve testing for short circuits and isolated stepped startup.

Opening a breaker for service and reclosing it should not require PPE, but only in my own opinion, as many interpret the 70E it indeed does. Closing onto a potential fault definetly does warrant fully rated PPE.

 

[zog]

I agree Zog, reclosing a breaker after a fault is NOT to be considered as a normal operation. The tripping itself indicates the potential presence of an abnormal condition and without investigating it should not be reclosed. Investigating it should involve testing for short circuits and isolated stepped startup.

Opening a breaker for service and reclosing it should not require PPE, but only in my own opinion, as many interpret the 70E it indeed does. Closing onto a potential fault definetly does warrant fully rated PPE.

Right, and in the senarios I was responding to it wa after a breaker tripped as a result of a protective action.

As far as routine opening and closing, I think an arc flash is possible but not probable, however as you stated the 2009 70E says PPE is required, it is stated clearly in the tables.