Slashdot Mirror
Solving a Wiring Mess?
FueledByRamen asks: "While trying to run a new power line for a large Sun mass-storage cabinet (located nowhere near a 220 outlet of course), I had the misfortune of needing to pop the lid on my main power distribution panel (previously opened in the late 80s). The whole thing is a rats nest and probably a fire hazard - old-style wiring with broken-down cloth/plastic insulation strewn everywhere, and the utility's incoming power cables have some sort of junction in them that's the size of a 1-liter bottle (on each wire) and is covered in layers of electrical tape. Even (gently) putting the panel back on jiggled something important, and there was a nasty cracking noise and half the breakers blew (all breakers in one of the 2 columns). I've worked with mains voltage in the past (wiring new rooms, installing lighting), but nothing on this scale, both in terms of complexity and potential for death. How do you industrious Slashdot readers go about fixing a mess like this (on a tight budget, no less) without getting a mains-induced glimpse at the great beyond?"
There's also insurance reasons as well. Having someone other than a qualified electrician do the work can void your fire insurance.
Don't resign. A worker can notify his supervisor that due to what the worker believes that doing the task placed before them will put them in imminent danger, he can refuse to do that task. The worker then needs to fill out a form or two and contact the Occupational Safety & Health Administration. The worker cannot be disciplined for refusing to work in a dangerous situation.
I've felt both a time or two (accidentally). 110 is really more of a tickle and certainly won't kill you.
You've got to be respectful of it but with 110 I didn't even realize I was being shocked until well after the fact.
Dude, 110 volts is most certainly enough to kill. True, most of us have been "tingled" by 110/115 a few times, and didn't die... all that proves is that we were lucky on those occassions.
For an interesting discussion of why low voltages *can* be deadly, see this page.
The bottom line is, lower voltages tend to be "safer" due to the resistance of your body, and the fact that low voltage power sources also usually have a fairly low current capacity. But try wetting your hands and grabbing the leads from an arc welder set on 200+ amps sometime, if you don't think low voltage can f#@k you up.
// TODO: Insert Cool Sig
It's the friggin' *law* in most jurisdictions to get a licensed electrician to do this work, and for very good reason.
In a facility I ran years ago I smelled smoke in our main distribution panel. Called our electrician and he *immediately* turned white, got out of there dragging me with him, closing the door to the small power distribution room behind him and immediately went to the building's main distribution breakers next to the elevator shaft on the bottom floor and turned off all power to our floor.
Why? He'd seen the insulation bubbling on the aluminum power cable that was connected to the main copper bus for the breaker box.
It had been connected without anti-oxidation gel and the aluminum had oxidized increasing resistance to the point where the insulation was near burning.
He told me that an electrician had been killed earlier in the year when a suburban shopping mall's main panel blew up as he was inspecting it, after having been called in during the wee hours of the night by the fire department after a report of smoke had been called in.
If the original poster's company doesn't own the building then the landlord can be forced to pay, just call in the friggin' city electrical inspector and after he shits his pants your building owner will be paying to rewire the box ASAP.
Don't have one of those? THAT'S BECAUSE YOU'RE NOT FARKIN' QUALIFIED TO DO THE WORK!
If you have not had the correct training, you CAN NOT safely lock out equipment. Sure. You locked it out. You stuck your wiggy in the wall socket to make sure you got a buzz. You tested each terminal and they were all dead. You started stripping wires. You reached way into the cabinet to unscrew some terminals in the back. It got dark and the building's outside lighting circuit turned on. Guess what? Someone ran the lighting circuit through the box.
oopsie.
You don't know what you're doing. Neither does the person who "told you how" to do this safely. Hire a professional.
"Reality is that which, when you stop believing in it, it doesn't go away." - Philip K. Dick
It's a great idea to call in an inspector periodically. Even the best-wired distribution box will eventually go bad and possibly cause a fire.
Why? Stuff expands when it is heated. Your connections are continually undergoing varying stresses depending on the current. When a connection works itself slightly loose, the resistance increases and the process speeds up.
Where I work, we have the local power service come in and take pictures of our distribution boxes with an infrared camera. That's a great way of pinpointing connections that are heating up too much.
This is the reason a computer can stop working, too...sometimes you can just pop the lid, wiggle everything and cinch it down, and it works.
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