Arcing when removing meter.

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Greg1707

Senior Member
Location
Alexandria, VA
Occupation
Business owner Electrical contractor
Today I pulled a meter and noticed a small amount of arcing when inserting the meter into the base. I had turned off the main breaker before removing the meter. Why would there be arcing?
 

growler

Senior Member
Location
Atlanta,GA
Today I pulled a meter and noticed a small amount of arcing when inserting the meter into the base. I had turned off the main breaker before removing the meter. Why would there be arcing?


Other than what infinity says about circuitry within the meter I can't think of anything. I have pulled and replaced many of the older meters and a few of the new smart meters and I have never noticed any arcing with the main open.

They changed out the meter at my house the other day but it already had a smart meter so maybe there is something wrong with the older version ( the service tech didn't know why they were being changed).
 

kwired

Electron manager
Location
NE Nebraska
Electronic meter still has a power supply for some of what is inside. What it draws should be very minimal, but if there is any transformer involved may be enough inrush current that will make more noticeable arcing when connected.

Mechanical meter shouldn't draw any current if there is no outgoing load
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Electronic meter still has a power supply for some of what is inside. What it draws should be very minimal, but if there is any transformer involved may be enough inrush current that will make more noticeable arcing when connected.

Mechanical meter shouldn't draw any current if there is no outgoing load
A mechanical meter still has voltage coils which will draw some current even when there is no connected load.
The PF will be very low. :)

Sent from my XT1585 using Tapatalk
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Today I pulled a meter and noticed a small amount of arcing when inserting the meter into the base. I had turned off the main breaker before removing the meter. Why would there be arcing?
Greg,

Was it a cloudy day when you saw this, or did you see it in full day light, or is the location a dark interior space? Or is the arc making a snapping noise that you can actually hear?

If you can hear a snap (crackle), I'd start trying to find the grow room, or the hidden lab.
 

kwired

Electron manager
Location
NE Nebraska
Greg,

Was it a cloudy day when you saw this, or did you see it in full day light, or is the location a dark interior space? Or is the arc making a snapping noise that you can actually hear?

If you can hear a snap (crackle), I'd start trying to find the grow room, or the hidden lab.

If you hear snap, crackle and pop, there just may be some Rice Krispies in there:D
 

Greg1707

Senior Member
Location
Alexandria, VA
Occupation
Business owner Electrical contractor
split bus panel

split bus panel

I am the OP. After thinking about this I feel foolish to report that I overlooked the fact that the service panel was a split bus. It had a breaker with "main breaker" stamped on the handle. I just turned that off without giving it a thought that it only disconnecting the general lighting load.
 

Coppersmith

Senior Member
Location
Tampa, FL, USA
Occupation
Electrical Contractor
I am the OP. After thinking about this I feel foolish to report that I overlooked the fact that the service panel was a split bus. It had a breaker with "main breaker" stamped on the handle. I just turned that off without giving it a thought that it only disconnecting the general lighting load.

I'm actually glad to hear this. Pulling the meter is one of the scarier parts of doing this job for me since there is no OCPD protection if I mess up.* Glad to hear there wasn't a hidden load.


*please save all the don't pull the meter comments for another thread. I'll be starting that never.
 

JFletcher

Senior Member
Location
Williamsburg, VA
I am the OP. After thinking about this I feel foolish to report that I overlooked the fact that the service panel was a split bus. It had a breaker with "main breaker" stamped on the handle. I just turned that off without giving it a thought that it only disconnecting the general lighting load.

Ah yeah old FPE and others have separate mains breakers, one for each leg. Glad you found the cause of the arcing and reported back here! :cool:
 

Greg1707

Senior Member
Location
Alexandria, VA
Occupation
Business owner Electrical contractor
assessing risk

assessing risk

I'm actually glad to hear this. Pulling the meter is one of the scarier parts of doing this job for me since there is no OCPD protection if I mess up.*

There is certainly an element of risk in removing and replacing meters. However, something I observed several years ago made me wonder about this task.

Dominion Power swapped out all of the meters in our area with new "smart" meters. In my neighborhood alone there are 1,800 condos with individual meters. It took one guy days to swap out all of these meters. This was a young man who looked like a college student type. He would show up in the morning in a mini van with new meters in boxes piled up on the back. He was wearing a t shirt and jeans and no gloves.
I asked him if he was a POCO employee. He was not. He had been hired as a temp by a energy company. He said the only training he and the other temps had was about 2 hours.

I suppose my conclusion is that his employer was either negligent or deemed there was little chance of a mishap in carrying out this task?
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I'm actually glad to hear this. Pulling the meter is one of the scarier parts of doing this job for me since there is no OCPD protection if I mess up.*

There is certainly an element of risk in removing and replacing meters. However, something I observed several years ago made me wonder about this task.

Dominion Power swapped out all of the meters in our area with new "smart" meters. In my neighborhood alone there are 1,800 condos with individual meters. It took one guy days to swap out all of these meters. This was a young man who looked like a college student type. He would show up in the morning in a mini van with new meters in boxes piled up on the back. He was wearing a t shirt and jeans and no gloves.
I asked him if he was a POCO employee. He was not. He had been hired as a temp by a energy company. He said the only training he and the other temps had was about 2 hours.

I suppose my conclusion is that his employer was either negligent or deemed there was little chance of a mishap in carrying out this task?


Wait till he pulls one that the "jaws" come out with the meter and he's standing there with live conductors still attached to the meter!:eek:hmy:
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Gee, thanks Bill. Now I have another thing to worry about :eek:.
It is sobering, isn't it?

Long time ago, now, I worked for a PoCo as a newly graduated electrical engineer. One of the things I was introduced to, in my couple years there, was a meter department training video (movie, then) about what could go wrong with a meter insert, or unplugging. The movie included a lot of high speed photography of the few seconds of a meter being hit with sustained fault currents of various values. Almost all of the examples showed the meter movement enclosure rupturing and exploding outward, in slow motion, as the solid metal conductors inside boiled into gas, expanding in volume by 1200 to 1600 times.

Ever since then, I have never stood in front of a meter that I'm handling at the instant of energizing.
 
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