Main Panel - Safe Work Practices


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Old 12-01-03, 09:09 AM
D
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Main Panel - Safe Work Practices

Comments in a number of threads expressing concerns about working on a main panel have caused me to wonder if there are "better" practices I could adopt or if there are things I do that are inherently unsafe. There are likely numerous other forum readers who have similar concerns. I would appreciate any comments from the "pros" out there that would help all of us "work safer." I worked as an electrician's assistant while in college and have re-wired three of my own houses, installed sub panels, and made numerous circuit improvments as a do-it-your-selfer. With that experience here is a short list of the practices I employ when working on a main panel.

1. Main breaker is always off when adding or removing a breaker.
2. Breaker is off when connecting or disconnecting a circuit.
3. When inserting or removing a cable, the ends of the cable are always directed out of the face of the box to avoid contact with the terminal bars or other wires.
4. When attaching wires to a breaker terminal I hold the wire with insulated lineman's pliers to avoid my hand contacting other wires or the panel box.
5. Neutrals are never doubled up on terminals but grounds are doubled up if space is tight.

I would also appreciate any comments regarding arcing within a panel (what causes it and how to avoid it) and any other hazards that I should be aware of.

I also appreciate all of time the "pros" on the forum spend to help the rest of us diagnose problems and make safe improvements. Thank you!

DavidJ
 
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Old 12-01-03, 02:05 PM
rob1kva
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Great post O.P., The most important thing I can add is that any DIYer who has even the slightest reservation about doing any kind of electrical work {even on deenergized circuits} should call a pro. Of course one should make sure the pro also knows his way around a C.B. panel. While I agree it is definately safer to work in a deenergized panel, in some cases its not the best way to go. I was taught if you shutdown the main C.B. on an old installation there is a chance the breaker will not reset, thus you are out the cost of a new main C.B. & possibly having to call someone in. There are 2 more ways you can protect yourself if you must work in a HOT panel: invest in a good set of 1000 volt rated
screwdrivers.
Always keep the hand that your'e not using
behind your back or in your pants pocket.This will
keep you from being a ground path
Almost forgot,arcing most commonly occurs at weak connections either at a junction box or loose terminations in a panel.
 
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Old 12-01-03, 02:27 PM
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Arcing in the panel

Originally posted by DavidJ

snip

I would also appreciate any comments regarding arcing within a panel (what causes it and how to avoid it) and any other hazards that I should be aware of.

Snip

DavidJ
Arcing is caused by any fault between the energized portions of the panels architecture and it's bonded cabinet or neutral buss. Arcing at that point in your homes electrical system can be quite destructive because of the amount of energy available. Events that might precipitate high energy arcing would include forcing a breaker onto a buss bar so that the bar deflects into the cabinet wall, forcing a tool so that it slips off the work and into an energized surface, allowing a knockout to fall into an energized portion of the panel.

Avoidance is best accomplished by planning the job so that the panel can be deenergized while working in it. If the service disconnecting means is located in the panel's enclosure cabinet then that will be difficult to do. As a minimum arrange all of your tools and materials within reach, provide an alternative source of lighting, and open the main breaker or the panels feeder Over Current Protective Device. Working in an energized panel leaves you only one step away from disaster.
--
Tom H
 
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Old 12-01-03, 11:39 PM
noxx
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If an old main would suffer a mechanical failure and not reset after being turned off, it needing replacing anyway. Badly.

I'm familiar with that failing, esp with Feds and push-a-matics.

I'm reluctant to give safety advice on working hot, because "by the book" it simply should not be done, without the required safety gear for the level of exposure. I'm sure folks are going to regardless...if you do find yourself in a hot panel, remove any rings and or watch you're wearing. wear comfortable and insulated gloves, long sleeves, and safety glasses. Do not skip on the glasses. A good fault can send hot metal flying into your face faster than you can blink.

If you feel uncomfortable doing it, do not do it. Weigh the risk and reward, you CAN be seriously hurt or killed, even in a residential panel.
 
 

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