Service panel for a condo has 6 AWG CU coming down from meter. No main disconnect, just a 60 amp breaker for the apt sub panel, a 25 amp breaker for the heat pump condenser, and a 15 amp breaker for the gas fueled hydronic boiler and tank water heater (in basement). All the conductors attached to the breakers are appropriately sized.
I’m wondering if the 6 awg feeders are enough or if they should be called out. In theory, close to 100 amps could be running through the feeders, no? I realize in practice it is much less, but figured the wire should be rated for the max. I’ve seen this setup before and called it out, but an electrician was needed for so many other things that it was an easy thing to have the electrician check. Same as last time, there are other defects in this panel so I’m adding this to the list again, but I was curious what others thought.
Also, on a different note, how many of you call-out a white, unlabeled grounded conductor being used as a ungrounded conductor when it is for the 240V to the condenser and it’s a straight run there (as seen in this panel)? I do to cover myself, but I don’t really feel like there is much risk since anyone working with that wire at either end would know that white wire is most likely hot. Again, asking out of curiosity.
#6 copper is good for 75amp service. You do not add the amp rating of the breakers to size the service, a load calculation is used to size the service. 100amp is today’s minimum, however, goes in the report as a note. As for identification of wires… since I expect a licensed electrician to perform any work on the panel I’m not too concerned with it as far as safety. I will mention it, however, saying before any work is performed by a licensed electrician all misidentified conductors should be marked per today’s standards.
thanks Simon. I realize you don’t actually add the breakers to size the service, but I see how I insinuated that with my comment about what could run through the wire. Really my concern is that there is no single main disconnect so the amount of flow going through the feeders could exceed what the wire is rated for. Sure, this is a similar situation as a split-bus panel and load calculation should determine the service conductor size, but in this case since the wires are only 6 awg, it raised an eyebrow. I have the comment about today’s 100 amp minimum in my library, so I’ll use that and tweak it slightly in my report for this situation.
You confirmed my feelings on the identification of wires.
I appreciate the quick response.
How big is this condo? I’m not sure what answer you wish to hear Heat and cooling don’t run at the same time. Is there also gas for cooking appliance? what about dryer? is there one in the condo? What it comes down to is this: if I thought the service is underrated due to everything being electric, then yes, I would request an electrician perform a load calc to verify service sizing.
Your comment about 6 awg copper rated for 75 amps brings up another question about #8 & #6 wire, a topic I’ve been a little unclear on - I’m going to post that right now separately to see what everyone says. I’d be curious to see what you say.
Your original answer was more than adequate, my thanks was sincere, not sarcastic. the ac was a mini split, which doubled as a heat pump, so it could run in the heating season. they had an electric dryer in unit and electric oven. gas cooktop. Like I mentioned, there were other issues like corrosion on some of the conductors and open knockouts, so I’ll just call out the SECs and an electrician can decide while he is there.
IMO there is nothing to report regarding the size of the service. A minimum size of 60 amps is permitted for a condo unit service so unless there has been a large load addition to the electrical system the original service calculation should be adequate. I would report the corrosion on several of the conductors on the neutral bus.
Thanks Robert. I see a lot of condos with 60 amp service and never call it out. This is the first time I can remember in a long time where there was no main disconnect, only the 60 amp breaker for the sub, so that is what made me reach out - to see how much concern there should be that the 6 awg wire didn’t have overcurrent protection right in front of it. Sounds like not something to be too concerned about. I mentioned it, but absolutely my primary callout was the corrosion on the neutral bus & wires.
I appreciate your response.
Heat and cooling don’t run at the same time. Is there also gas for cooking appliance? what about dryer? is there one in the condo? What it comes down to is this: if I thought the service is underrated due to everything being electric, then yes, I would request an electrician perform a load calc to verify service sizing.