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?"

Comments

Good grief

[mao che minh]

Good god man, leave that mess alone and hire a professional that knows what they are doing. Don't ever put your life in the hands of Slashdot; are you utterly insane?

Re:Good grief

[Catbus]

I think you get a qualified electrician to look at this and fix it. If the budget does not permit this, change the budget or consider the business failed. Next go-around, get better due-diligence review of the facilities. We techies can do some power if we are know what we are doing, but this sounds like it is out of our league. One may well have to turn off service power at the pole (or other building entrance) to redo this. Also, you are talking big conductors here, which our techie-tools can't handle. Leaving it alone is bad because there is already evidence of loose connections and grounding problems that will cause your 220 volts to vary over a wide range intermittently, eventually damaging the equipment, and possibly causing electric shock to employees touching poorly-grounded cabinets.

Auditioning for the Darwin award???

[TopShelf]

Maybe it's just me, but some things are worth paying for. I prefer juice in my stomach, not coursing through my entire body...

Good, cheap, fast: pick any two

[sphealey]

ow 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 is a reason why good industrial electricans charge a lot for their services: they work with dangerous stuff, and they know what they are doing. Get an estimate from a good one. If the powers-that-be refuse to approve the project, resign. That day.

sPh

Hmm, well now ...

[petabyte]

I might not speak for everybody but I'd imagine that the majority of people went "Hire an electrician" when they read that story. I really don't think you want to be mucking around in there with "some sort of junction in them that's the size of a 1-liter bottle" as you don't appear to know what that is (neither do I).

I know you want to save money but you're likely to fry the electric equipment in your establishment and might take yourself with it. Hiring a professional would likely be cheaper in the long run.

Two ways

[Compuser]

You have two options:
1. Read National Electrician's Code and the
Emerald book (IEEE guide). Then figure out
who installed the wiring and get a full layout
from them. Buy electrician's equipment as
necessary. Fix the problem.

2. Hire an electrician. You'll still need full
layout of your wiring.

If you have to ask...

[IIRCAFAIKIANAL]

... then you shouldn't be doing it.

Sorry, but this is the kind of thing that only years of experience can help with. If you didn't look at it and already know how to approach the problem, you probably shouldn't be messing around in there, unless you have all the time in the world to experiment and learn your way through the mess.

First I was surprised that IANAL advice hasn't landed some "Ask Slashdotter" in prison. Now we're aiming for our first fatality?

Don't fuck with it.

[Dr. Zowie]

It sounds like one of the main buses in the box got shorted out. You really need to get the thing rewired by a licensed electrician.

If the panel is at work, it's probably illegal for you to work on it. In the immortalized words of Beowulf Schaeffer, "Its Worth Yore Life And More To Go In There!" Seriously, as an uber-l337 633K, you probably have the ability to find the place where the short occurred -- but do you really want to (A) monkey around in a box with live current (it sounds like that is your main box, not a subpanel); (B) stick your neck out by breaking the law for your employer; and (C) possibly assume liability for burning down the building? No? I didn't think so.

If you're at home, you're probably allowed to work on it -- but most places require you to get an electrical inspector to look at it once you're done. Unfortunately, doing this requires getting the local electrical code, so that you know what you're doing -- and that's a whole separate rant. The National Electrical Code is adopted into most municipalities' building codes -- but it's copyrighted by the National Fire Prevention Association. Fortunately, the Supreme Court recently decided that it's unconstitutional to attempt to copyright the law of the land. Unfortuantely, you can't get the electrical code online yet -- you probably still have to buy it.

The buddy system and a couple of rules

[lateralus]

If you are not a certified electrician that has been trained to deal with that voltage range do not attempt to do so.

If you are going ahead anyway. Take another person with you at all times. Your buddy should be able to shut down the entire mains current within slit seconds. Your buddy should have a wood/rubber/plastic or otherwise insulating device that can be used to knock you away from the power source if necessary.

Never use both hands, current will flow through your heart and spine. Do not wear anything metallic such as chains, watches, rings etc.

Remember that even if you wear double or triple insulation that a high enough electrical potential can break through anyway. I work with 600+ Volt pulse LASER capacitors and I've seen arcs go through plastic.

To reiterate. If your not qualified do not attempt to do the job. Anything that you do based on any of the above is your responsibility only.

Good Luck.

You've GOT to be kidding!

[wcdw]

There is a reason that master electricians get paid the big bucks (and it's not all about just _surviving_, either).

IANAE, but anyone can play anything on the web, right? ;-) The situation you describe frankly sounds quite dangerous. Is burning the building down worth saving the cost of hiring a pro?

If you're *totally* determined to do it yourself, do the obvious. Turn off the upstream power (omit long-winded story of how to power a data center when the main is down - been there ). Make sure you understand what all the parts are, how to tell if they need replacing, and have replacements on hand before you start.

I would guess that there are innumerable sources of education and product sales in this area, so it shouldn't be *that* hard to figure out what everything is, why it is there and how to test it.

On the other hand, there *is* a learning curve involved, and I shouldn't need to point out the dangers of working on a *hot* box based soley on theoretical knowledge! How long do you have to learn how to fix it before you get more than just sparks?

Disclaimer: I've never done any hands-on on anything bigger than your average house feed. I do feel like I learned a lot from being a curious guy in general and having access to a Master Electrician for a couple years, including building out a new data center. And in your shoes, I would not undertake the task without hazard pay that would be higher than the cost of the electrician.

Another possibility is to call the power company, get them to take a look (say you smelled smoke, or saw sparks or something). I doubt they'll fix it, but they'll definitely escalate the problem for you.

As a devoted employee..

[coyote-san]

As a devoted employee trying to save your company money, the answer is obvious.

Step 1: Buy life insurance, lots of it. Name your employer sole beneficiary.

Step 2: Attempt to "fix" this yourself.

Step 3: PROFIT! The company can use the benefits (assuming the insurer doesn't use your actions as prima facie evidence of suicidal intent) to hire a professional to do the job right. You'll be dead, but that's a small price to pay, eh?

Seriously, what has our country come to where this is a legitimate question? Techies should be comfortable replacing wall switches and outlets, installing undercounter lighting, and other light work. But anything involving the main should go to the professionals without a second thought. If it's as bad as you said, it should also go to the lawyers - wasn't this building ever inspected? Who did this shoody work before, or allowed it to remain in such poor condition?

Think about it this way - imagine this was a manufacturing shop and people have routine cuts and burns and the like. No big deal, anyone with modest first aid skills can deal with it. But if somebody came in with a compound fracture and 4" of bone showing, would you patch them with the ace bandage and send them on their way? Or would you decide that this is one of those situations where you need to call in the professionals?

Electrician's Comment on 240V

[billstewart]

An American friend of mine was over in Australia, and watched an electrician who was being really conservative with turning all the power off while installing things. Since that didn't seem to be the usual Aussie approach to life, and since electricians in the US usually aren't that careful, he asked him about it. The guy replied that the difference between wimpy US 110 and 240 was "When you touch 240, you bounce about 3 meters farther.".

Basically, don't fsck with the stuff unless you know what you're doing.

Why Doctors are not Electricians

[sterno]

I lived in a rented house in college that had what turned out to be dangerous wiring.

LESSON 1: Polarity

Here's a cool tip for you. When wiring up electrical outlets, if you reverse the hot and the neutral lines, you actually create a voltage potential between the outlets. I discovered this because I touched the stove and the refridgerator at the same time accidentally. I got a huge jolt, shook a bit, and called the land lord.

LESSON 2: Breakers and Wiring Guages

If you should ever run wiring in your house, you need to make sure that the breaker that you use matches the capabilities of the wiring. If you should decide to run wiring into an attic using 15 amp capable wiring, it is a bad idea to put a 30 amp breaker on it. It's an even worse idea to hook up approximately 27 amps worth of electrical heaters to this circuit because it will cause the wiring in the wall to catch fire. Of course if one assumes that the person wiring the house isn't insane, you may not know to avoid plugging in said heaters.

LESSON 3: DOCTORS ARE NOT ELECTRICIANS

Eletricity isn't brain surgery, and just as you don't want an electrician siticking sharp metal objects into your brain, you don't want a doctor futzing with wiring. Actually I suppose if you are a doctor who does know how to work with electricity it would be okay, but the one who had previously owned our house had no clue on the subject. Worse, he had no clue and he mistakenly thought that he knew everything.

So, if you look in the electrical box and it instills fear in you, call a professional. Don't even think of doing it yourself.