ECN Forum Forums General Topics of the Trade General Discussion Area 150 Amp to 200 Amp Panel

Hi! Would love your input.

We recently renovated a condo. The condo building main breaker panel is 150 amps, the panel in the condo unit is 200 amps. The electrician who installed it didn't think that was an issue, but there was a 2 stage HVAC system installed. He only hooked up one stage because he was worried that if the 200 amp panel tripped it would trip the system for the whole building. The heat hasn't been keeping up in the winter because the other stage isn't hooked up. The new electrician thinks he can hook up the second stage without the breaker being tripped.

I can't find the code section that would relate to connecting a 200 amp panel to a 150 amp panel. Are there any code issues here or things we need to worry about?

Thanks

The real issue is the load calculation. The 150a will be the one that trips and the 200 in your sub panel is just going to be a disconnect.. I am guessing the conductors in the feeder are sized to the 150a breaker in the up stream panel. The 200 should be swapped for a 150 to avoid confusion
BTW I doubt the whole condo is on 150a, that is probably just the feeder to your unit unless this is a fairly small building.
I think it is time that you had a more in depth conversation with your electrician to see what is really going on. The second stage (the toaster wire heater) is probably 10kw or 15kw if this is a large unit. What size is the breaker going to the air handler? If it is 60a, a 10kw heater is likely. (assuming the condenser is another breaker)
Your electrician should be able to sort all of this out. It is probably beyond what you can trust an HVAC contractor to know. (Not really their field).