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Old 100A FPE subpanel remained after new 200A panel was installed

Old 100A FPE subpanel remained after new 200A panel was installed

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  #1  
Old 06-29-20, 03:16 PM
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Old 100A FPE subpanel remained after new 200A panel was installed

The previous owner of my house installed a new 200A main panel about 15 years ago. However, the old (circa 1940) 100A FPE panel with Stab Lok breakers is still live and serving mostly the kitchen and garage outlets. When I shut the mains off at the new panel, everything in the house is off but I have yet to determine if each Stab Lok breaker corresponds 1-to-1 to a same amperage breaker in the new panel.

Would the electrician have simply pulled new wire from the FPE panel to the new panel rather than just circumventing the FPE panel or is that not allowed by the code? There were other additions/upgrades done and those new circuits don't go through the FPE panel.

I've read a bit about how the FPE panel breakers may not trip when overloaded, but I've sort of assumed that the breakers in the main panel would if overloaded. How concerned should I be? FWIW, I'd be surprised if I ever exceeded a 50A load in the last 5 years because we rarely run AC and our stove, water heater and rarely used furnace are all nat gas.
 
  #2  
Old 06-29-20, 03:28 PM
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It is possible that old panel is being used as a sub-panel. Does your main panel have any breaker labeled sub-panel?
Probably has breaker size of 60A to 100A.

It is recommended to take out stab-lok as it is obsolete has a bad reputation.
It is possible to leave old wires in old panel and use it has a large junction box. However, breakers shouldn't be live if it is done like that.
If existing cables are long enough, it is best to move everything over to new panel. However, if they are not old panel is often used as a junction box. Normally, guts are removed when old panel is being used as a junction box.
 
  #3  
Old 06-29-20, 04:14 PM
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On a service change or upgrade..... a remote sub panel..... not sitting next to the main panel.... would not get replaced unless specifically requested. Your electrician should have told you about the issues with FPE so that it could be addressed.
 
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Old 06-29-20, 04:31 PM
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Thanks for chiming in. I thought I'd call it a sub-panel but I don't think it is fed by one large breaker from the main panel. So I think it's more of a junction box with stab-lok breakers on it.

Is the primary concern with Stab-Lok breakers in an FPE panel is that they won't trip or get jammed when overloaded? If so, aren't I somewhat protected by the main panel assuming each breaker on the FPE panel leads to the exact same size breaker on the new panel?

If it is still recommended to just get rid of the FPE panel, how difficult of a job is it to just convert it to a junction box? Is it just shut off power to the sub-panel and tie the connections together.
 
  #5  
Old 06-29-20, 04:48 PM
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It's either A or B .

A. The old FPE brand panel is fed by a single cable coming from the new 200 amp panel. The circuits still remaining in the FPE panel are unchanged and protected only by their original breakers respectively. This is a common method of panel upgrading and lets you move circuits to the new panel at your convenience.

B. Each circuit still going into the old panel has been unhooked from its breaker and a new short length of cable splicced on to continue to the new panel and a new breaker and slot. The circuit is protected only by the new breaker in the new panel. The old panel has already been converted to a junction box. Not likely done for you without telling you because there isn't that much space for splicing new wires when the guts of the old panel are still in the box.

No branch circuit will be protected both by its own old breaker in the old panel and its own new breaker in the new panel at the same time. Sometimes the do-it-yourselfer will move circuits to the new panel by using small junction boxes outside the old panel. This is because he wants to keep the guts of the old panel in place and alive during the moving job which usually takes several days for an amateur.

Do not unhook wires without first labeling them in a fashion that you could put them back the way they were if someone asked you to.
 

Last edited by AllanJ; 06-29-20 at 05:06 PM.
  #6  
Old 06-29-20, 05:46 PM
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I would take off the cover on the FPE panel and take a picture. You should be able to figure out quickly what the deal with it is.

If you're uncomfortable taking off the cover - turn off your main panel first.
 
  #7  
Old 06-29-20, 06:50 PM
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Be careful removing the FPE cover. The breakers may fall off the bus.
 
  #8  
Old 06-29-20, 07:05 PM
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I don't think it is fed by one large breaker from the main panel
Does turning breaker off at FPE panel turns off corresponding circuit in the home?

If so, you must have a breaker feeding your FPE panel because you said:

When I shut the mains off at the new panel, everything in the house is off

It is physically not possible to have both new and old breakers on the same circuit because these breakers use busbar.

Here are list of Stab lok hazards.
https://inspectapedia.com/fpe/FPE_Stab_Lok_Hazards.php

 
 

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