Uninterruptible Power to Receptacles

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Grouch1980

Grouch1980

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New York, NY
I'm working on a project where the client wants to back up 8 receptacles in a room, all on one 20 amp, 120 volt circuit, so that if normal power goes out, those 8 receptacles are still on with enough time to shut everything down. It's a room in a 4 story townhouse. I'm thinking of using a small UPS, but what UPS can I use where the output would hardwire to the 8 receptacles located around the room? Usually a small UPS has built in receptacles on its output. 20 amps x 120 volts, a 2.4 KVA UPS would be enough.

Thanks!
 
I dont know for sure if what I am suggesting is totally NEC compliant, but I have seen it in the wild.....

Home run from service panel to a 20 Amp single receptacle. The 8 receptacles that need to be backed up feed from a second box (which is nippled to the home run box). The second box, has a cover on it with a piece of "SO" cord having a 20Amp plug on it. The UPS would plug into the receptacle, and the protected receptacles into the UPS. If the UPS is removed permanently, the empty nipple would allow a compliant installation without it. IF the UPS need to be serviced or replaced, the cord can plug into the single receptacle.

Like I said dont know if this is absolutely NEC compliant, but it eliminates a special hardwire UPS, or modifying one....


Howard
 
g-and-h_electric said:
I dont know for sure if what I am suggesting is totally NEC compliant, but I have seen it in the wild.....

Home run from service panel to a 20 Amp single receptacle. The 8 receptacles that need to be backed up feed from a second box (which is nippled to the home run box). The second box, has a cover on it with a piece of "SO" cord having a 20Amp plug on it. The UPS would plug into the receptacle, and the protected receptacles into the UPS. If the UPS is removed permanently, the empty nipple would allow a compliant installation without it. IF the UPS need to be serviced or replaced, the cord can plug into the single receptacle.

Like I said dont know if this is absolutely NEC compliant, but it eliminates a special hardwire UPS, or modifying one....


Howard
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I was going to suggest something similar. This is how I've done it at Assisted Living homes.

You would think that you could purchase something that would allow for this type of install.
 
I think I follow... so the UPS input plugs into the single receptacle, and the SO cord 20 amp plug connects to the UPS output. I don't follow the purpose of the empty nipple between the boxes though.
 
If the UPS were to be permanently removed, it would be a simple matter to make the room wiring "conventional" NEC wiring without having to redo anything.... couple pieces of #12, and 2 blanks and the receptacles are "normal"


howard
 
g-and-h_electric said:
If the UPS were to be permanently removed, it would be a simple matter to make the room wiring "conventional" NEC wiring without having to redo anything.... couple pieces of #12, and 2 blanks and the receptacles are "normal"


howard
Click to expand...
Ah, I follow now. Thanks for the tip! With that I can select a UPS with a built-in output receptacle.
 
You could also have the second box and nipple as mentioned above, but put an inlet in that box instead of having an SO cord wired directly to it. Then you you could have a short "extension" cord where a female connector attaches to the inlet, and the other end of the cord plugs into the UPS output.

You could use either a straight blade 5-20P or a twist lock L5-20P inlet such as the ones at the links below:

https://www.gordonelectricsupply.co...ht-Blade-Flanged-Inlet-3-Way-20A-125V/5585911

https://www.gordonelectricsupply.com/p/P-S-L520-Fi-Fl-In-3W20A125V-T-L/2621998?text=P&S+L5-20P
 
Not sure if I'm following but is the suggesting here to go from a perminant wiring method add a receptical going to a temporary wireing method to a single UPS, then return into the perminant wiring method to the additional receptacles that is desired to be covered by the backup?
If so you maybe getting into a code glitch in that SO cord cannot be used as an alternative to the perminant wiring installation 400.12(1) (2017 NEC)
 
Fred B said:
Not sure if I'm following but is the suggesting here to go from a perminant wiring method add a receptical going to a temporary wireing method to a single UPS, then return into the perminant wiring method to the additional receptacles that is desired to be covered by the backup?
If so you maybe getting into a code glitch in that SO cord cannot be used as an alternative to the perminant wiring installation 400.12(1) (2017 NEC)
Click to expand...
Well, the whole thing is really a permanent installation. The problem is i'm not aware of a method or a UPS that can hardwire to output receptacles. Usually a small UPS comes with built-in output receptacles. That's not what I need... the output needs to go to receptacles located throughout a room... it's only a single 20 amp, 120 volt circuit.
 
Grouch1980 said:
Well, the whole thing is really a permanent installation. The problem is i'm not aware of a method or a UPS that can hardwire to output receptacles. Usually a small UPS comes with built-in output receptacles. That's not what I need... the output needs to go to receptacles located throughout a room... it's only a single 20 amp, 120 volt circuit.
Click to expand...
Google is your friend. There are a number of vendors who offer kits to convert their larger (>3kW) units to permanent wiring.
 
The installation instructions for the hardwire kit mentioned above says to disconnect a battery module before doing the wiring. This is in addition to turning off a switch on the unit. I don't think that method to disable power to downstream receptacles is going to be adequate for a permanent installation. And so I think you would need to place a disconnect after the UPS if you hardwire it.
 
synchro said:
The installation instructions for the hardwire kit mentioned above says to disconnect a battery module before doing the wiring. This is in addition to turning off a switch on the unit. I don't think that method to disable power to downstream receptacles is going to be adequate for a permanent installation. And so I think you would need to place a disconnect after the UPS if you hardwire it.
Click to expand...
Would a regular on / off light switch suffice? it's just a 20 amp 120 volt circuit.
 
synchro said:
The installation instructions for the hardwire kit mentioned above says to disconnect a battery module before doing the wiring. This is in addition to turning off a switch on the unit. I don't think that method to disable power to downstream receptacles is going to be adequate for a permanent installation. And so I think you would need to place a disconnect after the UPS if you hardwire it.
Click to expand...
So you go from breaker to the receptacle to the UPS, out of the UPS via hardwire kit, into the receptacles. If you want to kill the receptacles, turn OFF the UPS. Forget the light switch.
 
Of course, another solution would be to use multiple smaller UPS units rather than one larger one. They aren't all that expensive.
 
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