electrical question

[Bigjoemeat]

Hows it going.alright to the point. Right now I'm running a 1000w hps on a surge protector that's rated for 15amps..1800watts. I just ordered a dual socket light timer that's rated for 15amps also. If I plug in a 1200w mars 2 led in that 2nd socket of the timer would I be okay? Should I dim the ballast on the hps down to 750w? I only have one circuit to run off of. So only have room for 1 power strip.

 

[PeytonManning]

I'm not an electrical expert, but that sounds like a bad idea. Even if it holds the load, it could heat the wiring up and cause a fire

 

[newoldguy]

I agree with Peyton

 

[SolMJ]

Hey Big im not an electrician but I know you should never go over 80% of what your amps can handle. So in your case 1440w is the absolute maximum you should load. Stay safe.

 

[Bigjoemeat]

Ok thanks..so maybe ill dial down the hps to 750w and the 1200w led only uses 595 actual watts so that'll put it at 1345w..right? I should be good?

 

[Enderghast]

Your 1200w led is rated on LED watts. That is not the actual draw from the wall. I have not tested that one, but consider it to be a little over half, maybe 650w - 700w. This is because of varying voltages of different diodes. The reds are considerably lower than other colors for instance, and that brings down the actual current draw. You can buy a current meter very chealy, plug it into the wall and then your device into it and it will show you your actual current draw.

 

[Weaselcracker]

Careful with that timer. I've had one burn out before and it was a horrible sight. I came back home, the timer was a molten ruin and
there was a big black streak running all the way up the wall and smoke stains all over the ceiling. The smell lasted for a week. I was well under the rated power I could run through that thing and had been using it about a year. Apparently the cheaper timers aren't made all that well. (Duh...). Make sure you have some basic fire safety precautions going on and pay attention to how hot the connections are getting in regular use. Good luck

 

[Big Budha]

I also had one of those timmers that went bad. I now have a 20 amp industrial timer

 

[Weaselcracker]

Here's the thread I started after my mishap. Alienpus has some great info here Digital timers for digital ballasts

 

[go4snypr]

The big thing is the breaker on the circuit. If the breaker is good for 15 amps, it should trip before you smoke anything off. It SHOULD protect the circuit. but 1750watts at 120 volt is a 14.5 amp draw. your asking for troubles, at the very least blowing breakers. I would also bet that plug is not the only thing on that circuit. If there are other plugs, or lights on the same circuit you have more than 14.5 amp draw. In my area house hold breakers for 120v circuit are 15 amp, and the wiring in the walls is good for 20amp (the breaker protects the wires), and you can have up to 12 outlets (being light sockets or plugins) on one circuit. I would bet the socket you bought is rated @ 15 amp but is probably good for 20, as the breaker "should" protect it as well, but at 14.5 amps your asking for at the very least, blowing a breaker. and at 1345watts at 120 volt your at 11.2 amp draw, (again, you have to find out what else is on that breaker though)


and on a side note (i am not sure on this), the ballast for you hps may take more amperage on start up than it does once the bulb is up to temp. I know that electric motors can draw over 3x more amps on start up than once it is running.


Electrical Theroy


W=E(I)

W is wattage
E is Voltage
I is amperage

this the calculations for wattage, voltage, amperage. this should give you a start point to calculate what your trying to figure. I also believe the circuits should already be protected at 80% of what they can carry by the breaker, I dont think you should have to figure that kind of thing out when you plug stuff in....

 

[Weaselcracker]

I wish the breaker had caught mine. I suppose it was because I wasn't overloading the circuit to begin with- just a crappy timer that wore out. Lots of info on that thread I mentioned re. getting a better one.

 

[MacEFL]

Not a good idea. And can I assume you have fans on that circuit as well?

 

[towl35]

1750w/120v = 14.58 amps. Rounding up your load is 15 amp you need to size your overcurrent protection at a 125%. = 18.75 amps that said it would be a 20 amp breaker but you can only load up your circuit to 80% of the breakers size and that would be 16 amps on a 20 amp breaker which means you would need to get a 25 amp breaker (not sold in your local Lowe's or Home Depot) which calls for #10 wire (according to small conductor rule #12 cannot be protected at more than a 20 amp breaker). This is how it would be done to code by a professional. However, you can probably get away with the grow in your kitchen which has 2 20 amp circuits on the counter top (not at the wall by the floor) and #12 wire but you will NOT be able to use any other appliances on this same circuit.