I have a 100 amp single phase panel fed with a pair of # 2 feeders and a # 2 neutral wire. The internals of the existing panel are broken and the breakers keep falling out of place. I have a spare 150 amp panel that I would like to replace the existing panel with. Since there is very little load on the existing panel, just several 120 volt receptacles, can I install the 150 amp panel using the # 2 feeders ? I have a 100 amp and a 125 amp two pole breaker to feed the new panel with. Thanks for any info.
Replacing 100 amp panel with a 150 amp panel using same wiring.
- Thread starter steve61
- Start date
- Location
- Illinois
- Occupation
- retired electrician
You need 1 AWG conductors to supply a dwelling unit 150 amp service.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Yes you can use the 150 amp panel however the existing #2 conductors cannot be protected with a 150 amp OCPD. Depending on other variables you may be able to use a 125 amp OCPD to protect the existing conductors.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
Yes you can use the 150 amp panel but you need to feed it with a smaller breaker like the 100A if the conductors are aluminum.
Forgot to say. This is not a residential installation, but an industrial plant. The # 2 copper conductors are hooked up to a 100 amp two pole breaker. Since the conductors are protected by the 100 amp breaker, is there a problem with the 150 amp breaker in the new panel ? I wanted to use the 150 amp panel since I have it in stock. Or, do I have to just get another 100 or 125 amp panel ?( I would not normally install a main breaker panel in this instance, but my supplier sent me the 150 amp panel by mistake.)
- Location
- New Jersey
- Occupation
- Journeyman Electrician
You can use the 150 amp panel. The existing conductors are already protected by the 100 amp OCPD.
Is this a main lug only panel? If so, as long as it is rated 100A or higher you are fine. I have a 225A MLO panel in my house fed from a 100A breaker. If the subpanel has a main breaker, it is OK too if it is larger than 100A, but just may be misleading to some who think there is 150A available when the feeder limits it to 100A.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
You can feed a MLO panel with a breaker and conductors with the breaker rated at the panel rating or less. If a panel has a larger breaker than the feed who cares?
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
The 150A breaker would just be a switch in this case since there is correct OCP from the feeder.