My unfinished basement has a central vac on its own 20A circuit. The central vac is plugged into a 15A duplex outlet (not hardwired). I want to finish my basement and build a closet around the vac and the water heater.

Can I run additional outlets and lights off this circuit (all in the closet), or is that against the US NEC? I understand certain "fixed" appliances like ovens and dishwashers are required to have dedicated circuits, but this has a plug so I'm hoping it doesn't fall into that category.


  • What's the current draw in watts or amps on the central vacs nameplate?
    – Tyson
    Jan 21, 2017 at 1:56
  • 12A (....filler to get to 15 chars....) Jan 21, 2017 at 3:48

1 Answer 1


Is the vacuum unit fastened in place?

NEC 2011 210.23 Permissible Loads. ... A branch circuit supplying two or more outlets or receptacles shall supply only the loads specified according to its size as specified in 210.23(A) through (D)...

(A) 15- and 20-Ampere Branch Circuits: ...

(1) Cord-and-Plug-Connected Equipment Not Fastened in Place. The rating of anyone cord-and-plug-connected utilization equipment not fastened in place shall not exceed 80 percent of the branch-circuit ampere rating.

(2) Utilization Equipment Fastened in Place. The total rating of utilization equipment fastened in place, other than luminaires, shall not exceed 50 percent of the branch-circuit ampere rating where lighting units, cord-and-plug-connected utilization equipment not fastened in place, or both, are also supplied.

Utilization equipment is anything that connects to AC power.

You can have more than one installed device on a circuit, but if they total >50% of available ampacity, the circuit must be dedicated to them. In this case, a good installer will install a single (not duplex) receptacle.

If the water heater is already sharing a duplex receptacle with your 12A load, then it must be either

  • less than 4 amps, or
  • an MWBC. (multi-wire branch circuit, 2 hots sharing a neutral).

Most likely the manufacturer chose 12A because 125% of that is 15A, which makes it the perfect size for a 15A circuit. 125% because continuous load. Not that I vacuum for >3 hours at a time!

  • Hmm.. it's hung on the wall using a steel bracket, but not screwed to the wall. It's easy to disconnect from the vacuum tube, unplug it and lift it off the wall. Does that mean it's not fastened in place? If it IS considered "fastened in place" then does that mean it's already a code violation, since it's greater than 50% of the circuit rating and it's connected to a duplex outlet (the second outlet of which could be used for another device) ? Jan 21, 2017 at 13:48
  • Hard to say. A Dustbuster micro-vac also clips to the wall. The ruling factor would probably be whether it's sensibly useful as a portable device. Jan 21, 2017 at 17:20
  • Yeah, I think in all fairness, it's a "fastened in place" device, since the infrastructure (2" PVC pipes and all their receptacles etc.) is built around it to exist in that location. I have decided to replace the duplex with a simplex and run the other outlet(s) and light(s) in that closet on another circuit. Thank you very much for your help. Jan 22, 2017 at 18:53

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