Working Live

A

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Have a large area with about 30 fixture that are being replaced exactly "in kind"(same spot). They are 120/208v. Can you replace these live without turning off power? If so how would you do that without get hit? Thanks
 
Technically no they need to be de-energized according to OSHA. What kind of fixtures? Depending on how they're wired you might not be able to replace them one at a time without disconnecting several or all of them anyway. Lay in style fixtures with a fixture tail can be disconnected one at a time and replaced.
 
infinity said:
Technically no they need to be de-energized according to OSHA. What kind of fixtures? Depending on how they're wired you might not be able to replace them one at a time without disconnecting several or all of them anyway. Lay in style fixtures with a fixture tail can be disconnected one at a time and replaced.
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Pendant 1x4's. We are re-using the existing pendants.
 
CoolWill said:
Since you are an estimator, that implies that someone else is doing the work. Don't try to save a few dollars of someone else's money by putting an electrician at risk.
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I'd like to suggest a different perspective on 'working live'. What, exactly, does 'working live' mean?

It sounds like it is 'working on energized equipment', but what we really mean is 'working on energized equipment that was not designed with appropriate safeguards to be manipulated while energized because someone wanted to save money while keeping something on'. Think about it: we work with energized equipment all the time, but we don't give it a second thought because that equipment was designed from the start to be manipulated while energized. When was the last time you shut off a circuit breaker to plug an appliance in? When was the last time you called the power company to pull a meter prior to flipping a circuit breaker? We don't even think of this as 'working live' because the equipment is designed to be assembled, switched, controlled, etc. with the operator safely separated from dangerous voltage.

IMHO if some process is so precious that it cannot be interrupted, or if the process can be interrupted but it is simply expensive, then the system should have been designed from the get-go to be worked on while keeping your workers safe.

You have a computer process that cannot be shut down? Then you should have a backup system so that you can shift the load over to the other server, shut your primary server down, and get the work done. If having a backup server is too expensive, then you can't afford to keep your system up.

You want to keep your store lights on when they are being changed out? Your lights should be installed with receptacles so that individual fixtures can be removed and replaced _safely_ without endangering someone. If you can't afford to use connectors that let individual lights to be disconnected without 'working live', then you can't afford to keep the lights on while they are being changed out.

IMHO you should not be risking your life just to save corporate a few pennies. They want the system to be up all the time, they should pay for sufficient redundancy and safety equipment that you can work on the system without having to 'work live'.
 
infinity said:
Well I'm guessing 50 out of 100 electricians would have no problem disconnecting the existing 120 volt lights while energized. As mentioned it is not permitted by OSHA.
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I personally would likely do it hot as long as it wasn't a 100 year old overstuffed box. What I object to is expecting someone else to do it.
 
I wouldn't work on these live and I'd never ask anyone else to do so, either. If these are pendants, I guessing they are more than 8 feet above the finished floor. If you get bit on a 10-foot or 12-foot ladder, it isn't the shock that will do the damage, it's the sudden stop after the fall that will cause your bad day.
 
Alwayslearningelec said:
Have a large area with about 30 fixture that are being replaced exactly "in kind"(same spot). They are 120/208v. Can you replace these live without turning off power? If so how would you do that without get hit? Thanks
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Don't you have a shop SUPER?
Typically you will find these served in rows...daisy chained.
Disconnect at start of each row, repower, change that row.
Tag any that have EM Battery units...special case, right?
 
While there are times and places to work hot, planning to replace 2 1/2 dozen fixtures is not one of them. I’m not sure what you are planning to save by doing so, but the liability and violations aside, it takes a lot longer to work hot than it does to work disconnected.

At least I work a lot slower. And with one hand behind my back. YMMV. 😳
 
My take. It is very subjective depending on a multitude of factors. Many already mentioned here. I will say that as an estimator and a Project Manager I would never ask or TELL anyone to do it hot. IF the situations are right and comfortable I might look the other way if someone decided to do it hot. I might do it hot myself, but there is one other hard rule I have. If any person under my supervision refuses to do it hot, then I will not allow anyone else to do it hot, unless we are talking about something with myriad safety in place and multiple discussions and authorizations. My reasoning is that the person who refuses to do it hot is right or at least valid. Having someone else do it implies that the first person is "inadequate". Next time he/she may "just do it." and get killed.
 
I wouldn't need to de-energize it to lower the canopy and disconnect the fixture but as the estimator it should not be assumed that someone else would do so.
 
As an estimator, you need to know that it's illegal and unsafe to work on anything hot. Assume that the contractor will have to work with the owner to make arrangements to work safely and price accordingly. If the contractor decides to work hot it's on him. If someone gets hurt or dies, when it comes back to you at trial, you can show that you included an ample amount for the work to be done safely.

-Hal
 
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