Good morning,
I am doing my Safe Practices for the Home Inspector Course inspection assignment. I inspected the blower and coil boxes for my own electric furnace with heat pump and electric coils. The question is about the CBs pictured.The unit is within sight of the main CB panel.
Specificly:
What exactly do the CBs protect? Are they for a specific component of the system (coils maybe?) Or do they function as a disconnect for the entire system?
When I think disconnect, I think switch, but if these CBs are not acting as a disconnect, then am I correct in that this installation would not require a separate disconnect as it is in line of site of the panel?
I read the installation manual and spec sheet for the unit and it only refers to the knockout as being for the “circuit breaker or disconnect” location, I’m not sure if that means CB=dissconnect, or relates to options for 2 separate items. (Honestly, there’s probably more info in the wiring diagrams that is a bit beyond my understanding)
I also peeked at the Inspecting HVAC systems course that I haven’t yet taken and I’m not finding much at all on electric furnaces, same for InterNACHI YouTube channel for inspection videos.
Likely the labels tell a story that’s obvious to anyone with more HVAC and electrical knowledge than I currently posses.
Any insight or direction to further resources to answer my own question is appreciated.
It’s possible that both of these statements are true. One way to tell would be to turn the system fan to “on” instead of “auto.” Then go and throw these two breakers and see if the fan also turns off. Another hint would be if there are any other electrical cables entering the unit, although that would not necessarily be conclusive.
Either way, since the panel feeding the unit is in line-of-sight, the panel can serve as the disconnect.
Well, I probably shouldn’t be throwing breakers I don’t understand…but one of them definitely kills the blower. Don’t ask me how I know.
I’m still not confident it means everything is shut down inside tho, but it should, correct? Does this mean that If this unit was NOT in line of sight of the panel, then these breakers DO constitute a disconnect?
Yes, the two circuit breakers should disconnect all of the power to the unit. If you had a photo of the wiring diagram it would likely indicate this. Integral breakers that disconnect all of the power can serve as the unit disconnecting means. Also if the panel is within sight from the equipment that can also servce as the disconnecting means. That is defined by the NEC as within 50’ and within sight from the equipment.
Thanks all, this has been very helpful. I also eventually found this helpful video where the creator explains the CB wiring in detail as he opens the panel and disconnects them in a similar unit.
