Changing An Electrical Outlet Without Turning The Power Off

[UncleFred]

@Leaffan

Yes, it is not only possible, but even a lot of electricity providers have men in elevated “buckets” working on high voltage lines with no fear of electrical shock. Electricity needs a path back to ground. If one isn’t available then no hazard exists. Take a look at birds perched on 10 gazillion volt lines.

I have to voice some suspicion on this - are you sure those aren’t 240V wires, or maybe high-voltage wires that have been de-energized?

I used to work with Utilities. In one instance, I know they employed devices called ‘hot sticks’ that were like 6 foot long poles that were extremely non-conductive. (They had to be discarded every couple months just because they built up a slight amount of conductivity) These sticks were used when they needed to throw the large breakers/switches that activate/deactivate the high voltage lines.

Given how extremely careful they were just in touching (supposedly not hot) switch handles, I would not have expected anyone to touch an actual hot wire.

Now maybe they would do that on the 240V wiring running down the street, but that’s very different from the 4KV and up ‘high voltage’ referred to.

[billfish678]

My dad decided to work on a heating element of the water heater with the power on once. The screw driver got blasted across the room and half the shaft in one spot vaporized. The upside was that after that we had a pretty nice magnetized screw driver to hold and pick up screws and whatnots.

[Crafter_Man]

@boytyperanma

@Una_Persson

An electrician I had out just a few weeks ago claimed that you must ground the breaker box to the cold water pipe inlet as a secondary ground under code. Was he incorrect?

He was incorrect. You are required to ground the pipe to the panel. But it’s not like wires only let power go one way, so if the houses actual ground failed the piping would function as a secondary ground. That isn’t the intent of the code however. The code wants you to ground any metal components of the structure in case a wire comes lose or what not and touches the metal it will ground out and throw the breaker.

If a live wire hit metal that was ungrounded nothing would happen until some poor sap came along and completes the circuit to ground electrifying themselves in the process.
The largest topic of the electrical code book is ‘grounding and bonding’ it is simple in theory but put to print it gets very complex even very experienced pros get the terms mixed up, then there is the ever popular mistranslation of customers or electricians attempts to translate the language into something they can follow.

IANAE, but I think it can be summed up this way:

Let’s say you’re installing a new 120 VAC receptacle. There are three connections to the receptacle: hot, neutral, and ground.

The hot connects to a circuit breaker inside the breaker box. The neutral connects to the neutral/ground bar inside the breaker box.

What to do with the ground?

Let’s say you go outside, pound a 4-foot copper rod into the soil, and run a wire between the receptacle’s ground connection and the copper rod. Would this be O.K.?

No - there would be too much resistance between the receptacle’s ground connection and the neutral/ground bar inside the breaker box.

When installing a receptacle (or anything else), there must be a good, low resistance path between the receptacle’s (or device’s) ground connection and the neutral/ground bar inside the breaker box. In other words, you need to run a copper wire between the receptacle’s (or device’s) ground connection and the neutral/ground bar inside the breaker box.

The ground connections of *all *receptacles, appliances, devices, etc. must be connected (via copper wires) to the neutral/ground bar inside the breaker box.

Once this is all done, the neutral/ground bar inside the breaker box must be connected to the earth (using a copper rod) in one or more places.

[Claude_Remains]

@t-bonham@scc.net

@Claude_Remains

This is why you should never flip breaker switches till the unit you are gonna work on is “off”. If you are not sure of what you are doing, please shut off the entire home at the main.

But that can cause much more problems elsewhere.

First, hope that power cut didn’t hurt any computers, home theatre systems, stereos, etc. that are in the house.

Then think about all the items that will have to be reset once you turn the main power back on: clocks, bedroom alarm clocks, computer clocks, VCR/DVD clocks, TV clocks, thermostat clock, microwave clock, etc. And then there are all the the items that need to be reset/reprogrammed: re-program/rescan your digital TV channels, re-program stations on your radio, re-record your answering machine message, reset your kitchen stove, reprogram the individual setting on your washing machine, etc., etc. (Some of the newer ones might have batteries that will last for a few hours – assuming the batteries aren’t dead.)

This will involve a whole lot of work for you (or the homeowner) to do afterwards, to get the house back working as it was before you came to ‘fix’ the wiring.

A better action is to study the situation until “you are sure of what you are doing” before starting to do the work.

As I said upthread I always do work while everything is “hot” but I will not advise others to do so.

[Inigo_Montoya]

@billfish678

As for working on a live line to keep you safe because you’ll be more carefull…well, I think thats macho BS IMO.

Not macho in my case, just lazy disrespect of the danger, pure and simple.

[Chefguy]

@md2000

You unhook the wires one at a time from the old outlet and attach to the new socket- first the two white, then the two black; do the ground last or first; don’t touch anything. I still burned one outlet when it touched the side of the box while being pushed in.

I was an electrician for a lot of years and I believe that you are incorrect here. It’s been a long time, but some things stay with you. In addition to touching one wire at a time, you want to avoid an open neutral while the hot wire is still connected. Disconnect the hot wire first, the neutral second, the ground last, never first.

[johnpost]

@boytyperanma

The largest topic of the electrical code book is ‘grounding and bonding’ it is simple in theory but put to print it gets very complex even very experienced pros get the terms mixed up, then there is the ever popular mistranslation of customers or electricians attempts to translate the language into something they can follow.

@Crafter_Man

IANAE, but I think it can be summed up this way:

The ground connections of *all *receptacles, appliances, devices, etc. must be connected (via copper wires) to the neutral/ground bar inside the breaker box.

Once this is all done, the neutral/ground bar inside the breaker box must be connected to the earth (using a copper rod) in one or more places.

The grounded connections of receptacles, appliances, devices, etc. must be connected to the ground bar inside the breaker box, they are not connected to the neutral bar.

There is a difference in a service entrance and subpanels and other structures for the above issues as well.

Grounding and bonding is a complex issue and that is why it occupies so much of the electrical code.

[Crafter_Man]

[quote=“johnpost, post:67, topic:548545”]

@boytyperanma

The grounded connections of receptacles, appliances, devices, etc. must be connected to the ground bar inside the breaker box, they are not connected to the neutral bar.

Correct me if I’m wrong, but inside a home’s primary electrical panel, aren’t the neutrals and grounds connected together via a common bus bar?

[Rick]

Well in my panel at least the neutral and ground are two different bus bars in the box, but they are connected electrically.

[Joey_P]

[quote=“UncleFred, post:61, topic:548545”]

@Leaffan

Given how extremely careful they were just in touching (supposedly not hot) switch handles, I would not have expected anyone to touch an actual hot wire.

Now maybe they would do that on the 240V wiring running down the street, but that’s very different from the 4KV and up ‘high voltage’ referred to.

Watch as they get near the wire. They use the stick to bring themselves, the helicopter and the wire all to the same potential. They get on to the wire and you can see as the helicopter potential drops.

Also, on an episode of This Old House, they had to cut the main wires running into the house to move the service entrance. Their electrician climbed up the ladder, cut the wires, did what he needed to do (touching bare copper the whole time) and reconnected them. When Kevin asked who you call to have the power to the house shut off, he replied that it was live the entire time, but he was very careful to only have one exposed wire at a time and he was on a fiberglass ladder so getting a shock really wasn’t an issue…of course he was still very careful.

[johnpost]

@Joey_P

Also, on an episode of This Old House, they had to cut the main wires running into the house to move the service entrance. Their electrician climbed up the ladder, cut the wires, did what he needed to do (touching bare copper the whole time) and reconnected them. When Kevin asked who you call to have the power to the house shut off, he replied that it was live the entire time, but he was very careful to only have one exposed wire at a time and he was on a fiberglass ladder so getting a shock really wasn’t an issue…of course he was still very careful.

on electrical forums i saw many people saying what he did was poor. he was leaning the ladder against the structure and he was leaning over structure. so it wouldn’t take much movement of him or his clothes for him to be grounded. he was careful and lucky.

[johnpost]

@boytyperanma

The largest topic of the electrical code book is ‘grounding and bonding’ it is simple in theory but put to print it gets very complex even very experienced pros get the terms mixed up, then there is the ever popular mistranslation of customers or electricians attempts to translate the language into something they can follow.

@Crafter_Man

IANAE, but I think it can be summed up this way:

The ground connections of *all *receptacles, appliances, devices, etc. must be connected (via copper wires) to the neutral/ground bar inside the breaker box.

Once this is all done, the neutral/ground bar inside the breaker box must be connected to the earth (using a copper rod) in one or more places.

@johnpost

The grounded connections of receptacles, appliances, devices, etc. must be connected to the ground bar inside the breaker box, they are not connected to the neutral bar.

There is a difference in a service entrance and subpanels and other structures for the above issues as well.

Grounding and bonding is a complex issue and that is why it occupies so much of the electrical code.

@Crafter_Man

Correct me if I’m wrong, but inside a home’s primary electrical panel, aren’t the neutrals and grounds connected together via a common bus bar?

the neutral bar and the grounding bar are different entities. at a service entrance, and no where else (including breaker panels) in your electrical system, they are bonded together with a bonding conductor.

your first statement above is incorrect as you wrote it.

[Snnipe_70E]

In a pinch I have done it. It is not something someone with out experience should do at all. And with experience it should not be done.

[boytyperanma]

@johnpost

@Joey_P

Also, on an episode of This Old House, they had to cut the main wires running into the house to move the service entrance. Their electrician climbed up the ladder, cut the wires, did what he needed to do (touching bare copper the whole time) and reconnected them. When Kevin asked who you call to have the power to the house shut off, he replied that it was live the entire time, but he was very careful to only have one exposed wire at a time and he was on a fiberglass ladder so getting a shock really wasn’t an issue…of course he was still very careful.

on electrical forums i saw many people saying what he did was poor. he was leaning the ladder against the structure and he was leaning over structure. so it wouldn’t take much movement of him or his clothes for him to be grounded. he was careful and lucky.

His safety practices were lacking but that is how it is done. When upgrading or changing a service those wires are live. You use a fiberglass ladder cut the old wires and connect them to the new wires. You are supposed to use rated gloves for the procedure. Many old timers don’t use the gloves as they are a pain in the ass to work with. They are thick and limit your dexterity. The gloves have a listed expiration date before you need to get a new set.

I usually opt to use the gloves but I’ve done changeovers without them a couple times. I don’t own a set,. I borrow one if needed. Electrical is not my primary gig. I avoid this type of work.

Doing the change over reminds you how heavy wire is. The aerial wire is much thinner then the service drop but is still a heavy gauge. When you are up on a ladder holding a hundred feet of wire taught trying to clip the neutral into the tension clip it demands some strength. That wire hitting you will kill you almost without a doubt. The thing that’s going to stop that current is the transformer exploding. Same goes for dropping the wire. It hitting the ground is going to leave you with some explaining to do.

New construction is much easier. You run the drop up the side of the house and from there it is the power companies problem. They run the wire across dead then connect it on the house side. After the wires secured on both sides they can connect the power at the pole. The last connection being live.

[Gary_Robson]

I have worked on hot wiring, but never on purpose. In one case, I had turned off the wrong breaker, and found out when I melted the tip of my inadequately-insulated screwdriver. In another, we were removing a wall. I called out to the fellow I was working with to turn off the breaker. He yelled, “Okay, it’s off.” I cut the wires, made a spectacular show of sparks, and left a hole in my cutters. I felt it, even through the insulated handles, and fell over backwards–mostly out of surprise.

There was a pause, and then I heard his voice say, “Oh. That breaker.”

He got me a nice new pair of diagonal cutters for Christmas.

[GusNSpot]

Every transformer around here has a fuse and an disconnect. Only one customer to each transformer. They will come disconnect for you. In the cities that is not necessarily true…

[Sam_Stone]

I think some of you need to treat electrical energy with a little more respect. Electrocution kills quite a lot of DIYers every year. Don’t screw around with it.

When I studied power engineering years ago, I was taught that if you were unsure whether wiring was hot, work with one hand behind your back to make sure you weren’t providing a path to ground that went through your chest.

That may have saved me this year - I bought a new dishwasher and range, along with a new over-the-range microwave to replace the old range hood, and installed them myself. When i removed the old appliances, i went to the breaker box and flipped off the breakers marked ‘dishwasher’ and ‘appliances.’. Then I tested the wiring for the range hood and dishwasher, and both were off.

I installed the new microwave, but was missing some plumbing bits for the dishwasher, and couldn’t get them until the next day. So, I capped the wiring for the dishwasher and flipped the breaker on for the range hood.

The next day I got the plumbing bits and pushed the dishwasher into place and plumbed it. Then I checked to make sure the dishwasher breaker was still off, removed the caps from the wiring, and hooked up the ground wire. When I started to hook up the hot wire, it touched the grounded box, and sparks flew everywhere. At any time I could have electricuted myself, except that I still treated the wires as ‘hot’, even though I didn’t think they were. I made sure I wasn’t grounding my left hand or body, and used insulated pliers for everything.

So what happened? The electrician who wired the box mislabeled the breaker. The dishwasher was wired into the ‘appliance’ circuit. The day before I had switched both off, and tested both to have no power. It was a fluke that I happened to turn off the other breaker at the same time. If I had replaced only the dishwasher, I would have caught the mislabeled breaker the day before.

But this is how accidents happen. A fluke, a combination of unlikely events that catch people napping. It’s easy to tell yourself that you’re smart enough or experienced enough to take safety shorcuts, and you might get away with it for a long time. But you’re playing Russian Roulette with fate. So don’t cut corners.

[cplif]

Sam Stone has the word, If you play around with live electricity without strict need and training, you will at best get surprised, and at worst get toasted to obituary.
As a plumbing/heating guy, I’ve been restoring houses and flats for about 25 yrs. I have been surpised so many times by electrical defaults(defects) that ONE rule is imperative: NEVER TRUST ANYTHING. Treat every wire as hot, any voltmeter will do, but you need 30 seconds to test hot, neutral, and ground, half a second more to check an independant ground, DO IT
We have seen everything you couldn’t imagine, circuits wired to neighbors, hot grounds running current to appliances, hot grounds running full voltage with welded circuit breakers, etc etc If you put your paltry flesh in there…
Don’t forget that a live circuit also may have … microwave capacitors (blast you crisp) old TV caps, tubes, faulty transformers, (a gas furnace igniter will tickle you with 30 to 50 000V) a ground fault in an oven or heat plate can run quite high without showing if the installation is “rusty”
If you don’t care so much for your own well being (and thos of your loved ones) don’t forget all those appliances with circuit boards (boiler, furnace, fridge, TV etc…) that do not at all appreciate ground faults, or jolts up a neutral wire, (that beautiful spark you made when wirering your outlet)

[JFLuvly]

Also it only takes about three seconds to jam the leads of your meter into a receptacle that is known to be working to get a reading. This way you know your meter is working. I have seen digital meters with bad batteries that give false readings.

[johnpost]

@boytyperanma

@johnpost

@Joey_P

Also, on an episode of This Old House, they had to cut the main wires running into the house to move the service entrance. Their electrician climbed up the ladder, cut the wires, did what he needed to do (touching bare copper the whole time) and reconnected them. When Kevin asked who you call to have the power to the house shut off, he replied that it was live the entire time, but he was very careful to only have one exposed wire at a time and he was on a fiberglass ladder so getting a shock really wasn’t an issue…of course he was still very careful.

on electrical forums i saw many people saying what he did was poor. he was leaning the ladder against the structure and he was leaning over structure. so it wouldn’t take much movement of him or his clothes for him to be grounded. he was careful and lucky.

His safety practices were lacking but that is how it is done. When upgrading or changing a service those wires are live. You use a fiberglass ladder cut the old wires and connect them to the new wires. You are supposed to use rated gloves for the procedure. Many old timers don’t use the gloves as they are a pain in the ass to work with. They are thick and limit your dexterity. The gloves have a listed expiration date before you need to get a new set.

I usually opt to use the gloves but I’ve done changeovers without them a couple times. I don’t own a set,. I borrow one if needed. Electrical is not my primary gig. I avoid this type of work.

Doing the change over reminds you how heavy wire is. The aerial wire is much thinner then the service drop but is still a heavy gauge. When you are up on a ladder holding a hundred feet of wire taught trying to clip the neutral into the tension clip it demands some strength.

sometimes a service entrance change over has to be done hot.

he could have used gloves, put a mat down on the roof, moved the ladder he was working from to the other side to put himself a bunch more inches away from the structure in a safer vertical manner.

i would have done at least one of the three things.

pulling a hundred feet or better of triplex taut is a hard task. good reason to take a break after its done.