Panel Change out Question

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Gary Dagley

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Cedar Hill Texas
One of our electricians changed out a panel for a customer .
Here is where the problem started, he did not number the wires he just removed and installed new panel and put the wires where ever they would reach.
That is where the problem started.
In the hallway the lights were blinking then went out so they called us back out, unfortunately the original electrician was out of town so we sent someone else.
He found the customer had 200 plus volts at the three way hall switch. He didn't know what to do so he traced the circuits back to the panel,
and then proceed to move a breaker up one spot to put on same phase, and all is working fine now.
The problem is now you have two breakers controlling one circuit.( or not )

so how would we test for this before we remove old panel?
 
When we change a panel we label all the wires that come off a 240v breaker and mark what amp breaker was used.

If the 120v breakers were gauged for their ampacity then we don't mark them. It is important to get the 240V back the way they were. The 120v circuits will fall in place easily after that
 
Gary Dagley said:
He found the customer had 200 plus volts at the three way hall switch. He didn't know what to do so he traced the circuits back to the panel,
and then proceed to move a breaker up one spot to put on same phase, and all is working fine now.
The problem is now you have two breakers controlling one circuit.( or not )

so how would we test for this before we remove old panel?
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I'm thinking that you had a multiwire branch circuit on two different phases with a common neutral that was open.

The only way to get things straigth is to troubleshoot the problem and get things wired back correctly.
 
Dennis Alwon said:
If the 120v breakers were gauged for their ampacity then we don't mark them. It is important to get the 240V back the way they were. The 120v circuits will fall in place easily after that
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It's really not a bad idea to mark the wires. We don't have a lot of multiwire branch circuits here for residential. But since some panel change out will be commercial it's a good habit to get into.

Like you I make sure to mark the 240V circuits first and re-identify any white wires used as hot conductors.
 
It sounds like you have a Carter or Chicago three-way controlling those lights. Under normal conditions the lights are off if both conductors have zero or 120 volts on them (both grounded and ungrounded wires are hot, or not with 0V potential between them), 120 volts if they are on. The neutral wire switches, ie can either hot or not, between them. That method of wiring 3 ways has been against code for 90 some years, but you still see him from time to time.

Due to the nature in which Chicago or Carter 3-way switches are wired, you may not be able to convert it to a code correct installation without pulling new wire
 
It doesn't matter what was going on before if you install the circuits back as they were previously you should not have an issue.
 
When I turn the breakers on after a panel change out on an older house I turn them on one at a time and check the lugs at the other breakers to see if there is a wire coming back to the panel hot. Found it a couple times.
 
Dennis Alwon said:
It doesn't matter what was going on before if you install the circuits back as they were previously you should not have an issue.
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The original poster mentioned the electrician landed the wires wherever they could go. If there were two circuits in the switch box and both were previously on different Breakers but on the same leg, and they are now on different breakers on different legs, that could explain the 200 volt plus reading.

also the original poster maybe making the assumption that everything in the house worked or was wired correctly before he changed the panel out, an assumption that's probably in error.

PS Welcome to The Forum Gary
 
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JFletcher said:
also the original poster maybe making the assumption that everything in the house worked or was wired correctly before he changed the panel out, an assumption that's probably in error.
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The OP never said why the panel was being changed in the first place.

I changed out a little 100 Amp FPE panel for a friend in one of his rental properties that he was selling. I just assumed the panel change was part of the sales agreement. After changing out the panel and starting to correctly mark the circuits I discovered there were about three seperate problems on the branch circuits and this was the reason they thought the panel needed to be changed.

Not a bad idea to get rid of an FPE panel if you are trying to sell a house but it won't solve branch circuit problems. I think all the problems were bad back stab receptacles and were easy to find.
 
growler said:
The OP never said why the panel was being changed in the first place.

I changed out a little 100 Amp FPE panel for a friend in one of his rental properties that he was selling. I just assumed the panel change was part of the sales agreement. After changing out the panel and starting to correctly mark the circuits I discovered there were about three seperate problems on the branch circuits and this was the reason they thought the panel needed to be changed.

Not a bad idea to get rid of an FPE panel if you are trying to sell a house but it won't solve branch circuit problems. I think all the problems were bad back stab receptacles and were easy to find.
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In that case, I would also offer to replace all the devices in the house. The house would show better anyway, because they would all look new.
 
You never know what you'll find in an old panel. We look at the neutral bar to see if their are any black wires on it. If so will mark it black. Same thing with the breakers all the 240's get taped together.
Every now and again you'll see a single white wire on a breaker. Will tape it black.
Mind you the wire is so old that it's light brown. But you can distinguish if you have the original blacks and whites.
Then we check all the 240s to see what their feeding. Then place them on the appropriate size breaker.
 
What I started doing was marking wire with color tape. Say 30 amp dryer blue on both wires, 30 amp a/c two strips of blue on each wire, hot water tank gets 3 strips on so on.
 
I number every wire that was landed on a breaker with the slot number. Later when I'm reassembling the panel, whites with no numbers go on the neutral bar. Everything else gets landed on a breaker and I refer back to slot on the old panel to determine what kind of breaker I need. I always put everything back the way I found it except I will downsize breakers that are too large for the conductors. I will also reorganize the panel based on wire lengths and aesthetics. When it comes time to fill in the index, the slot numbers on the wires are again used to lookup the purpose of each circuit. This job already takes 6-7 hours to do. I would hate to have to do troubleshooting after I turn it on. The way I do it, I rarely have to.
 
Sounds like a lot more work without figuring out what is going on. The company may want to set up a new guideline to at least photo the panel if not check labels and number before tearing it apart. The mwbcs really need to be marked and kept with their neutral
 
guschash said:
What I started doing was marking wire with color tape. Say 30 amp dryer blue on both wires, 30 amp a/c two strips of blue on each wire, hot water tank gets 3 strips on so on.
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It would be a minor miracle for me to find a panel that had the correct breakers for an AC unit.

I normally check the AC units to see what size breakers they should have.
 
gaelectric said:
When I turn the breakers on after a panel change out on an older house I turn them on one at a time and check the lugs at the other breakers to see if there is a wire coming back to the panel hot. Found it a couple times.
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I do the same test, but do it BEFORE I change the panel out. I want to know if I need to add charge for correcting backfeeds and also don't want to be blamed for causing them in the changeover.

Mark
 
leave breakers in panel

leave breakers in panel

After years of not doing so I started a new practice when replacing panels. I start on the upper left side of the old panel and snip off the wires from the breakers leaving a small amount of wire and insulation protruding from the old breakers. I do not remove the breakers. Once I have completed this with all of the breakers I have the old panel with all original breakers in place with the the small portion of the original wires/insulation showing. In the event of a later question I can refer to the old panel.
 
Greg1707 said:
After years of not doing so I started a new practice when replacing panels. I start on the upper left side of the old panel and snip off the wires from the breakers leaving a small amount of wire and insulation protruding from the old breakers. I do not remove the breakers. Once I have completed this with all of the breakers I have the old panel with all original breakers in place with the the small portion of the original wires/insulation showing. In the event of a later question I can refer to the old panel.
Click to expand...

Sounds ok for a breaker panel, but not much good for a fused panel, which is the majority of my panel changes.
 
JFletcher said:
It sounds like you have a Carter or Chicago three-way controlling those lights. Under normal conditions the lights are off if both conductors have zero or 120 volts on them (both grounded and ungrounded wires are hot, or not with 0V potential between them), 120 volts if they are on. The neutral wire switches, ie can either hot or not, between them. That method of wiring 3 ways has been against code for 90 some years, but you still see him from time to time.

Due to the nature in which Chicago or Carter 3-way switches are wired, you may not be able to convert it to a code correct installation without pulling new wire
Click to expand...

:thumbsup:
I think that's what you might have here. Had a similar experience years ago. I've always known this setup to be called a "California 3-way" in old houses with knob and tube. A hot and neutral were run to each 3-way and wired to the traveler screws on the switch. A single conductor was run from the common screw to one side of the light. The light operates, but the polarity changes - totally illegal today. It sounds like each switch was originally fed from different circuits, but were on the same leg so there was never a problem until the panel change.
 
Every K&T job I've worked on (and there have been plenty over the years) have had the 3-ways wired the "right" way.
 
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