I want to add some outlets and/or lights in the crawlspace because I'll be
working in it for a long time, and it would also help future inspection (I
check it once in a while).
I have read past posting about wiring crawlspace and still have some
(1) Since the crawlspace may be wet, I'd like to use waterproof junction
boxes. Do I also need to put the cables in conduit? Metal or plastic?
(2) Can I tap the power from any convenient junctions I can find, or do I
need to run a separate circuit from the panel? Is there a limit on how many
receptacles one circuit can feed? If I want to install a sump pump, I
remember reading that each motor load of a certain current requires its own
dedicated circuit, is this true? If so, what is the max current pump I can
use that does not require a dedicated circuit?
It shouldn't be that wet but you should put everything on a GFCI for
your own safety. You are sitting in the dirt.
Any general lighting circuit should do for this since it is a minimal
load and infrequently used.
You should be looking at a new circuit when you get up around 1/2HP
but if you did, you could also put the rest of your lights in the
crawlspace on that fairly safely. I would GFCI everything after the
If your thinking of just some work lights so you can see well enough to
crawl around why not some 12 volt outdoor lights, easy to install no
Then put a proper outside outlet with GFCI and weatherproof cover just
outside the crawl space access.
if you put a sump pump in a crawl space it must be GFCI protected....
Receptacles don't use current, things plugged into receptacles use current.
If there is only one receptacle, people will plug everything into that.
Counting receptacles will not give you any meaningful indication of current
usage. Some people use 1 1/2 amp per receptacle and the code does too in
certain instances, but it is nonsense. Only that which is being used or
likely to be used matters. Count that!
Multiply the motor running current by 1.25, then deduct that figure from
the current rating of the circuit in question. What you have left is how
much additional lighting you can put on the same circuit. If you expect
that lighting to be on for 3 or more hours, along with the motor running,
then you would have to multiply that additional load by 1.25. That is for
It's not a bad idea to have the lighting on a different circuit in case you
mess with the pump and cause it to suck something into the impeller that
hangs up and locks the motor rotor....tripping the breaker. You don't want
the lights to go out on you while your down there. Always have a backup
penlight. Dark trips back are not fun when all you can see are little eyes
looking back at you and spiders crawling down your back.
Be sure you can disconnect the pump within sight of your sump hole. You want
to be able to work on it in situ without someone turning it on. I'd put
everything down there on GFI. As for the lights, I've got keyless
receptacles in my crawl space with incandescent lamps. They always burn out
and I don't want to climb around 4 corners of my crawl space to change them.
Consider fluorescent strip lights or those new screwshell fluorescent lamps.
They last many many years. It's nice when the crawl space is fully lit and
the monsters can't sneak up on you in the dark.
Good luck with your project,
Randy R. Cox
Out at my cabin the crawl space is such that I can sit up and work down
there. When built I had one circuit dedicated there and mounted all the
fixtures, switch box, duplex outlet box on the side of floor joists. The
switch is right at the access door. So when I open it I can reach it and
turn the lights on.
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