I would like to remove an existing cable from the breaker panel, that feeds a single home run outlet, and wire it to a consumer UPS that I will locate near the panel, through a junction box.
Questions:
- To join the power cord from the UPS to the junction box can I put a NEMA 5-15 inlet on the box and use a consumer power cord?
- Instead of a NEMA inlet (a) could I do it with an IEC C14 inlet? (b) could I just insert a consumer power cord into the box with strain relief and splice wires inside the box? This would all be on the surface near the breaker panel, nothing inside walls but also no conduits.
- As a further optional step, if the junction box additionally is fed raw power and I add a switch to bypass the UPS, can I just switch the hot or must the neutrals be switched too? The grounds? I assume the UPS input and output grounds are bonded but I don't know about the neutrals. The inlet hot would never be connected to the raw power hot, but is there still any unacceptable danger in this arrangement?
This question is instructive but the answers focus on the practicality of running new cable from room to room. My situation is to use existing, to-code, wiring from the basement to the room, and adds the idea of switching to raw power.
Best Answer
Yes.
You can run an isolated electrical line, using normal in-wall wiring methods, from a single inlet to outlets.
The inlet will need to be in the NEMA family. A C13 inlet won't cut it for at least 2 reasons off the top of my head: first it lacks the necessary ampacity, and second it is voltage-agnostic, and the inlet needs to be keyed to reject a power source of the wrong voltage.
As far as having a built-in switch, same rules apply as for a generator. You must have exactly one neutral-ground bond in the entire system. Not zero, not two. ("two" is its own special kind of 'bad'). If the power source bonds neutral and ground, then you must switch neutral. If it does not, then you must not.
The best bet is to switch neutral, but not bond neutral around the switch - have the isolated circuit draw neutral only from the switch. These types of switches are expensive, so I'd just do cord-and-plug myself.
You would never have a reason to switch safety ground.