840w LED lights 15 amp or 20 amp breaker?

Drop That Sound

Drop That Sound

Well-Known Member
Yeah AFCI. GFCI senses ground faults.

The thing is, you have to be careful using it as a breaker, because it could "ghost trip", and shut down the whole grow when your not around. Nuisance tripping is a thing, and some equipment doesn't like to run on it.

Probably better to isolate just a few of the circuits, only for some of the things you plug in.

I'm not exactly sure whether or not it's a good thing in this situation, but at least you won't get shocked.
 
Drop That Sound

Drop That Sound

Well-Known Member
You can get gfci surge protectors later. Good for plugging in multiple pumps and hydroponic stuff. Growing on racks with multiple flood trays and lights under them, etc.

Or you can get the outlets. All my lower outlets are protected in my grow area's. One outlet in a circuit can protect all the rest of the non gfci outlets down the line too.

I don't know much about AFCI breakers, or if they are safe for grow lighting, or how reliable they are...
 
B

Bud man 43

Well-Known Member
Drop That Sound said:
Yeah AFCI. GFCI senses ground faults.

The thing is, you have to be careful using it as a breaker, because it could "ghost trip", and shut down the whole grow when your not around. Nuisance tripping is a thing, and some equipment doesn't like to run on it.

Probably better to isolate just a few of the circuits, only for some of the things you plug in.

I'm not exactly sure whether or not it's a good thing in this situation, but at least you won't get shocked.
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I agree- and a gfci outlet or gfci breaker needs to be changed out as they do have a service life.
 
CWF

CWF

Well-Known Member
Recently tested outlets in a house my son rented (using a simple 3-light Ideal tester with GFCI test button). House is about 30 years old.

EVERY SINGLE GFCI in it was wired wrong: line to load and vice versa. The downstream outlets all failed test. Had to rewire every dang one of them.
 
CWF

CWF

Well-Known Member
Exactly above is correct - I only wish half of the electricians out there knew this:

If the GFCI is cross-wired line-to-load, the GFCI receptacle itself will still trip upon a ground fault test, but the downstream receptacles won't, which is UNSAFE. This is easy to detect in YOUR place with one of these cheap testers. What matters is your place. Is it wired right?
 
HydroDawg421

HydroDawg421

Well-Known Member
I have 30A breakers (and the upgraded wiring in the walls) for my 240v grow lights. They use half the amps that 120v uses.
 
UpstateRecGrower

UpstateRecGrower

Well-Known Member
Lilmink said:
I am running four 840w grow lights , will need to install new breakers. Should I put each on a separate breaker? Should I use 15a or 20a?
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Looks like you got a lot of responses, some wrong info as can be expected lol, but you'll want 2x 20 amp 120v circuits for those lights (I assume you're using 120v plugs and not 240v?) 20 amp 120v circuits are good for 1920 watts after the constant use derating. 15 amp will be just a little too small at 1440 watts (after derating).
 
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Bud man 43

Well-Known Member
UpstateRecGrower said:
Its a common fallacy to mistake power draw and amps, even though you're using half the amps you're using twice the voltage so the draw (watts) are the same.
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Amps equal watts divided by volts
If you double the volts - you halve the amps
The math doesn’t change because of whatever you are calling power draw.
Electricity is measured in amps- volts and watts. No such thing as “ power draw”
Most fitness clubs use 240v equipment because it used half the power of a home 120v unit- i have one and it states this clearly in the manual.
M4BC73F20-D5CA-4178-A9EC-73C14B0505A2.png
 
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UpstateRecGrower

UpstateRecGrower

Well-Known Member
Bud man 43 said:
Amps equal watts divided by volts
If you double the volts - you halve the amps
The math doesn’t change because of whatever you are calling power draw.
Electricity is measured in amps- volts and watts. No such thing as “ power draw”
Most fitness clubs use 240v equipment because it used half the power of a home 120v unit- i have one and it states this clearly in the manual.
MView attachment 5166111
Click to expand...
It uses the same amount of power, there is no power savings. Amps does not equal the power used, watts does.
 
HydroDawg421

HydroDawg421

Well-Known Member
Bud man 43 said:
Amps equal watts divided by volts
If you double the volts - you halve the amps
The math doesn’t change because of whatever you are calling power draw.
Electricity is measured in amps- volts and watts. No such thing as “ power draw”
Most fitness clubs use 240v equipment because it used half the power of a home 120v unit- i have one and it states this clearly in the manual.
MView attachment 5166111
Click to expand...
Cool. I was speaking about cutting the amps in half by using 240v versus 120v.
 
L

Lilmink

Well-Known Member
UpstateRecGrower said:
Looks like you got a lot of responses, some wrong info as can be expected lol, but you'll want 2x 20 amp 120v circuits for those lights (I assume you're using 120v plugs and not 240v?) 20 amp 120v circuits are good for 1920 watts after the constant use derating. 15 amp will be just a little too small at 1440 watts (after derating).
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They added a 60 amp double breaker in the main breaker box , subpanel has a 20 amp double breaker. Not sure what these double breakers are actually called haha Four 20 amp outlets and two 20 amp GFCI outlets. Can't wait to plug everything up and test it out.

Everything I am running is 120v
 
Charles U Farley

Charles U Farley

Well-Known Member
Arc fault protects against fire- gfci protects against shock
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That's why I use AFCI outlets for all grow lights, fans, etc. AFGI protected circuits are more likely to trip during surges/sags but it's worth it to me for the peace of mind.
 
UpstateRecGrower

UpstateRecGrower

Well-Known Member
Lilmink said:
They added a 60 amp double breaker in the main breaker box , subpanel has a 20 amp double breaker. Not sure what these double breakers are actually called haha Four 20 amp outlets and two 20 amp GFCI outlets. Can't wait to plug everything up and test it out.

Everything I am running is 120v
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Awesome, sounds like you've got plenty of headroom for other equipment now as well!
 
Cvntcrusher

Cvntcrusher

Well-Known Member
Lilmink said:
I am running four 840w grow lights , will need to install new breakers. Should I put each on a separate breaker? Should I use 15a or 20a?
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so an 840 shouldn’t even use 9amps when it starts up i would assume a 15 would be fine but why not run the 20?
PJ Diaz said:
I'd like to see a source cited for that theory.
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this guy always says the same thing in every power discussion
 
farmerfischer

farmerfischer

Well-Known Member
Depends on the gage of wiring. 14 gage wire for 15amps 12 - 10 gage for 20amp.. its possible to over heat the wiring running to high of a breaker through to small of wiring.. you can, but some times the breaker wont fail/break properly
 
farmerfischer

farmerfischer

Well-Known Member
Lilmink said:
I am running four 840w grow lights , will need to install new breakers. Should I put each on a separate breaker? Should I use 15a or 20a?
Click to expand...
15- 20 amp Breakers pop at 1750- 1800watts .. you could get away with two breakers but is alittle risky and only could run just the lights
 
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