Circuit Capacity - Fire Hazard?

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Oakmanthruthefloor

Member
Hi, I'm hoping some more experienced folks can tell me if my proposed basement setup is safe or needs refinement. I ran a new 20 amp circuit to the room (12ga wire) and have three 20 amp outlets in the grow room. I also have an exhaust fan hardwired to the new circuit.

1 outlet is mounted on a wall, just below my floor joists, and will be for oscillating fans, maybe a dehumidifier. Not really concerned about that one.

The other 2 outlets are in a dual gang box, pigtailed, and is mounted on a floor joist, middle of the room, facing down. This will be where I plan to hook up my two led lights, each pulling about 450 actual watts @ 4 amps. I was also planning on using smart outlets as timers although I could also use an old fashioned timer as well. This one gives me a little pause as something about having 900 watts and 8 amps in one box running 18 hours a day makes me nervous. Especially if it's facing down.

I am not going over any limits here on my circuit as far as I can tell. But can you tell me if I need to do anything differently here? I love this forum and really appreciate the info and opinions you all share.
 
Chip Green

Chip Green

Well-Known Member
The only thing I can see there, is it's pretty easy to get close to the threshold of a 20A circuit, when the dehumidifier kicks on.
The one I run sucks up 6A on it's own. 8A of lamp, a box fan, a scrubber, and exhaust, and suddenly 18A are coming in....(I like 15 or less)
Without a dehuey, I'd say your plenty clear.

Paging @Renfro .....
 
Renfro

Renfro

Well-Known Member
Oakmanthruthefloor said:
This one gives me a little pause as something about having 900 watts and 8 amps in one box running 18 hours a day makes me nervous. Especially if it's facing down.
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This alone shouldn't be an issue unless you have loose connections in the box and an arc occurs, in this case a cover better be on the box. The whole idea of the box is to contain an arc.

You can only use 16 amps (80%) of a 20 amp feed before the breaker starts tripping. Thats 1920 watts. Minus the lighting that leaves you 8.5 amps for everything else.
 
PadawanWarrior

PadawanWarrior

Well-Known Member
Renfro said:
This alone shouldn't be an issue unless you have loose connections in the box and an arc occurs, in this case a cover better be on the box. The whole idea of the box is to contain an arc.

You can only use 16 amps (80%) of a 20 amp feed before the breaker starts tripping. Thats 1920 watts. Minus the lighting that leaves you 8.5 amps for everything else.
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I was waiting for you to answer this one. I almost mentioned you in the thread, since it sounds right up your alley, but thought you might see it anyways. I definitely know who to go to if I need any electrical advice.
 
Renfro

Renfro

Well-Known Member
If there is another existing circuit handy that could handle the load of the dehumidifier then it's probably ok. A dehu is gonna push that over the limit. I personally like to run dedicated circuits for loads like dehumidifiers / AC's. You did good running a 20 amp feed and not just a 15. The cost difference is minimal and the 4 extra amps are worth it IMO.
 
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Oakmanthruthefloor

Member
Solid advice and feedback everyone, this forum continues to be so valuable. I really appreciate each one of you for taking the time to respond. It sounds like I should be fine...I have done a fair amount of electric work in my basement remodel (home studio and home theater) but nothing with this much draw in one outlet so I wanted to float it by some experienced folks as safety is paramount here. I do have another circuit in the basement for the dehumidifier but I may run another 20amp to be dedicated for it, just to be extra safe.
 
Notthecops

Notthecops

Active Member
Renfro said:
This alone shouldn't be an issue unless you have loose connections in the box and an arc occurs, in this case a cover better be on the box. The whole idea of the box is to contain an arc.

You can only use 16 amps (80%) of a 20 amp feed before the breaker starts tripping. Thats 1920 watts. Minus the lighting that leaves you 8.5 amps for everything else.
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Agree 100%. Only issue is if you have loose connections. No fire hazard as long as it’s wired correctly. The breaker will trip if it’s over capacity, eliminating any possibility of fire.

I don’t like using smart plugs as timers. If your internet goes down, lights won’t go on or off. I also find they are not reliable all the time. I made my whole home a ‘smart home’ I have switches, plugs, dimmers etc. I find the timers don’t always work reliably enough To do it in my grow room. I’d hate for the lights to go on, but not the fans, causing heat issues. Or in my case, the pump not coming on causing them all to dry out.

I use these for timers. They have battery back up so if the power goes out, everything is still timed. I run 1000 watt hps/mh lights off these, no issues.

VIVOSUN 7-Day Dual Outlet Digital Program Timer UL Listed: Amazon.ca: Patio, Lawn & Garden

VIVOSUN 7-Day Dual Outlet Digital Program Timer UL Listed: Amazon.ca: Patio, Lawn & Garden
www.amazon.ca
 
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Oakmanthruthefloor

Member
My connections are tight, I take my time and make sure everything is 100% correct before I put the covers. Each outlet gets tested as well once the breaker is installed and turned on.

Yeah, I think I'm going to ditch smart plugs as a timer option...just another failure point I don't need in my system. Yay, now I get to do more research :)...I have zero experience with digital vs. mechanical timers.
 
GBAUTO

GBAUTO

Well-Known Member
Renfro said:
This alone shouldn't be an issue unless you have loose connections in the box and an arc occurs, in this case a cover better be on the box. The whole idea of the box is to contain an arc.

You can only use 16 amps (80%) of a 20 amp feed before the breaker starts tripping. Thats 1920 watts. Minus the lighting that leaves you 8.5 amps for everything else.
Click to expand...
Is the 80% rating for continuous use or intermittent?
 
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