Desertboy said:

I'm on 230v (Whole of EU is, UK used to be 240v and rest of europe was 220v but they standardised it) we always worked on 5amp per 600w which has worked fine. UK actually still mostly runs at 240v because it falls within the tolerances agreed with the EU.

I don't really know much about US electrics as far as I understand you run 110v at the sockets but the power comes in at 220v into the consumer unit as is stepped down for the sockets. 220v is available for high power items (Cookers, aircons, heaters, etc.)

Is this correct?

In which case the original poster never mentioned if it was a 110v or 220v panel which was the first thing that sprung to my mind and why I wrote the first post.

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3N1GM4 said:

No more than 127 thirteen watt cfls...

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Desertboy said:

I'm on 230v (Whole of EU is, UK used to be 240v and rest of europe was 220v but they standardised it) we always worked on 5amp per 600w which has worked fine. UK actually still mostly runs at 240v because it falls within the tolerances agreed with the EU.

I don't really know much about US electrics as far as I understand you run 110v at the sockets but the power comes in at 220v into the consumer unit as is stepped down for the sockets. 220v is available for high power items (Cookers, aircons, heaters, etc.)

Is this correct?

In which case the original poster never mentioned if it was a 110v or 220v panel which was the first thing that sprung to my mind and why I wrote the first post.

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Natural said:

I don't understand how you are calculating 5 amps for each 600 watt light though?..that would be the amp draw for us running a 600 watt light at 120v. Watts divided by volts equals amps.

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Desertboy said:

No I'm in UK at 230v (Although last time I tested the power it was still actually 240v which is within the specs) so usage is just under 3 amps but add 2 amps for the initial powering up spike and wiggle room. I also sized my contactors the same way.

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bigger buds said:

I'm running 10 1000 hps from 50 amps subpanel. Total current draw 45 amps. Other bells and whistles on different circuits

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Myco said:

Yo OP, for sake of answer your question in technical terms, assuming you're referring to 1k lights dedicated to a 200amp panel with absolutely nothing else on that panel... technically you could run up to 35 1k lights continuously on a 200amp panel if you want to be safe and up to code.

Load should only be 80% of rated capacity. So 200 amps x .8 = 160 amps.

Assuming you're operating 240v ballasts (which you should be running that many lights) at 1000w... 1000 / 240 = 4.16 amps per light. But that's assuming the voltage feeding your panel is exactly 240v, this varies house to house, and can even fluctuate in the same house. So for a bit of fudge factor, assume 4.5 amps per light.

160 amps / 4.5 amps = 35kw continuous load.

But again, this is all assuming you have more than one 200 amp service at your location. If you only have one 200 amp service coming in, then obviously that changes things.

You would also obviously keep in mind what is all going to be providing a continuous load, factor in flip-flopping light cycles with separate flower rooms, etc etc. Also taking into account any other equipment on the same panel.

To be quite honest, coming in here to ask that question you may want to do some heavy research or hire an electrician.


This should technically be on a 60 amp circuit. Rule of thumb is a circuit should only operate at 80% of it's capacity.

Hope your wire is sized properly...

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Natural said:

hey Myco..long time bro! Us sparky nerds huh? I think he's looking more for legal advice. Like "ya bro you can run 10-12 lk's with AC's and as long as you pay your bill your cool" haha..but if ya gotta ask..are ya? :)

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