[rickywb]

I had an up grade to my panel (100amp from 60amp) and the Electrician pulled meter and hooked aligator clips to the hot side of meter and ran a temporary light so he could see what he was doing. I thought hot side was 440 (220 each side). And is that dangerous?
Rickywb

 

[micromind]

I've done the same thing many times. The voltage at the meter is the same as at the panel. The only hazard here is the wires clipped to the meter socket are not fused, but if a short were to occur it would simply blow the clips off. Not a very big spark at all.

Rob

 

[300zx]

I have done the same thing ,but if the power co. shows up they will not be to happy about it. They have caught me couple of times said they would fine me next time but never do so far.They say you are stealing power.(120 each side)

 

[Scuba_Dave]

It's dangerous if he hits both sides while connecting/disconnecting
Or if it were to slip off
But really not that dangerous

 

[jimmy21]

Dangerous if it were left alone but supervised for a few hours, I see no problem

 

[Speedy Petey]

I've done the same thing many times. The voltage at the meter is the same as at the panel. The only hazard here is the wires clipped to the meter socket are not fused, but if a short were to occur it would simply blow the clips off. Not a very big spark at all.

Rob, you forgot the smiley or laughing face after this.


I too have a temp power setup with big alligator clips. I don't use them much with all the battery tools I have. If the job is more than a service change that's what they make generators for.

Sure, clipping on to the meter or service drop is using un-metered power, but only a prick from the power company would actually call it stealing.
I'll gladly give him the $.37 it cost to cut those 2x4's. :laughing:

 

[nap]

I've done the same thing many times. The voltage at the meter is the same as at the panel. The only hazard here is the wires clipped to the meter socket are not fused, but if a short were to occur it would simply blow the clips off. Not a very big spark at all.

Rob

who says they aren't fused? You most assuredly can fuse your taps. Obviously there will be some portion of the wire and the clips that will not be fused but you can place an inline fuse for protection.

actually, an inventive person could fabricate a device that would fit into the cutout for the meter with integral fuses and taps and maybe even a disco. I would make it so installing it would allow the base of it to fit in the cutout before clip contact so as to allow a safe install while hot:whistling2:

as to not a very big spark; a friend told me of a time he was working on a 120/208 panel ; hot. He made a mistake and he said the fireball that singed off his eyebrows was a site to behold, especially since he was arms length away from the initiating contact. You have to realize the amount of current available at the meter is simply put; A LOT. More than enough to vaporize whatever wire you have hooked to it.

I see you present a lot of near brilliant info MM but it sounds like you might want to go back and review the basics.

work safe or risk death. It happens real fast.

 

[Scuba_Dave]

I had not considered how much power is available at the meter
I was thinking it was stepped down at the transformer to house current?
But is that the 100a, 200a, or 400a that matches the panel?

Or the fact meters are usually located with easy reach of a child

 

[nap]

I had not considered how much power is available at the meter
I was thinking it was stepped down at the transformer to house current?
But is that the 100a, 200a, or 400a that matches the panel?

Or the fact meters are usually located with easy reach of a child

the current would be controlled by any fusing the POCO has in place and simply, what they can supply. If you will look at a breaker, it will have an AIR number. That is the rating (in amps) that device is designed to be able to interrupt without extreme desctructive forces being released (blowing up). Most household devices have a 10,000 amp interrupting rating. Commercial services can go quite a bit higher than that.

most pocos will feed multiple houses with one transformer. That transformer has to be able to provide enough current for all of those houses at once. On top of that, there is the instantaneous current that a fault causes before any circuit interrupter has the time to react. As an example, a typical household breaker is designed to allow around 5 times name rating before it trips instaneously. That means it will take around 100- 120 amps current for a 20 amp breaker to trip instantly. Now extrapolate that to a POCO that is serving 5 200 amp services on one transformer. Sometimes there are many more services on a transformer. It all depends on what the poco installed.

Just as bad though is since the POCO system is fused so high compared to what it takes to kill a person, should a person become energized, there is a chance he will not flow enough current to blow a POCO fuse and will simply continue to be cooked until he somehow breaks the circuit.(insert really ugly pictures here)

as to a meter within reach of a child: they are quite safe unless disturbed and they are generally tough enough to withstand general abuse. Obviously, if a person were determined, they could get into a meter and there is more than enough power to kill within easy reach.

I have less problem with the meter than I do with the open service drops. They are supposed to be safe due to the consctruction of the feeder cable (neutral is wrapped around the hots so any cut should cause a neutral to hot short and cause a fuse to blow) but I have seen entrance cables where the neutral wrap has nearly fallen off and would not afford the same protection as a new cable.

I it is obvious that do be granted the miracles of electricity, we do place ourselves in a less safe condition but we, as a society, have accepted the dangers so as to enjoy the benefits.

 

[micromind]

I really didn't think the clip leads would make a very big bang, so I tried it.

I connected an old 125 amp meter base to a 100 amp breaker, made up a 14/3 cord with some 5 amp alligator clips, and connected the other end of the cord to a switch. The meter base was tie-wired to a pole about 5' high, to simulate actual conditions. This is important, as explained later.

Once energized, I flipped the switch on, thus causing a direct short. One of the clips blew off, sort of a nice POP, and not as big of spark as you'd expect. The end of the clip was missing, and there was some evidence of arcing on the jaw.

The reason is because the weight of the cord caused the clip to be pulled away from the meter base jaw, thus extinguishing the arc quickly.

The size of the arc, and subsequent explosion is directly related to 3 things. Voltage and current (obviously), impedance across the arc, and duration of the arc. Impedance sort of cancels current, so the main factor here is time. Think milliseconds. When the short is caused after the clip is installed, the heat from the plasma ball (rapidly expanding gasses) plus the weight of the cord blows the clip away from the jaw quickly, thus preventing the arc from growing very much.

Had the clip lead been shorted when it was installed, that'd result in a MUCH larger arc. And very likely a trip to the ER. The reason being that the clip is being moved toward the meter base jaw, and your hand is much heavier than a clip. Thus the arc would have enough time to grow. Quickly. (Remember...milliseconds). This is the reason why a circuit breaker with a higher interrupting rating has a stronger spring. To pull the contacts open quicker. It's also the reason they snap on and snap off.

I'm somewhat hesitant to post this on a DIY forum, I certainly don't want to encourage anyone to try such a thing. If you don't have a LOT of knowledge and experience, blowing stuff up with electricity is extremely dangerous. My intention here is education as to characteristics of electrical arcs. Some are easily controlled and result in little damage. Most are completely out of control, and cause considerable damage and worse, hurt and kill people.

Rob

 

[frenchelectrican]

I'm somewhat hesitant to post this on a DIY forum, I certainly don't want to encourage anyone to try such a thing. If you don't have a LOT of knowledge and experience, blowing stuff up with electricity is extremely dangerous. My intention here is education as to characteristics of electrical arcs. Some are easily controlled and result in little damage. Most are completely out of control, and cause considerable damage and worse, hurt and kill people.

Rob

I can understand your feeling and I feel the same way I am not too crazy to give out the answer in case some of the DIY don't understand how strong the arc blast espcally with " bolted fault " aka short circuit I have see the meter socket blow apart { once with bad meter BTW it was 480 volts } ( Rob ., this is a 400 amp direct bolted meter socket }

There one advice to all DIY the best thing is keep your hand off from the meter socket "gut " {inside meter socket }

I just have a service call not too long ago { got back in few minutes ago } one guy working on the sliding and he " pry " the meter socket off the wall so he can get the new vinal siding behind.,
Guess what it did nice damage inside the meter socket and yeah it destoryed the SE cable along the way.
The cuprit was a screw fell inside and hit the line post and the screw shorted out between the line and netural lugs.

{ a side note here the POCO's in my area will be more than happy to tempory take the meter off and get the mounting screws out of the meter socket and put the meter back in the place some will not charge for doing that and some will charge depending on the condition of service riser/latheral and it only take couple minutes to do that }

Merci,Marc

 

[Speedy Petey]

I'm somewhat hesitant to post this on a DIY forum,

As well you should be!

I am surprised at these posts from you as well.

 

[DangerMouse]

huh??? then does that mean sticking the wires on your tongue while standing in a puddle ISN'T the right way to test for voltage????
wow! ya learn something new every day, huh?

DM

 

[Scuba_Dave]

I had my new meter installed on a piece of plywood flush with the base. That way I only have to side up to the meter & not under