[VIganjafarmer]

Hello fellow growers

I was wondering if i could put 2 120v 1000watt ballast on a single 20amp breaker? the lights are the only power I'll be pulling from that breaker.

Thanks

[bobcat1963]

Short answer is no.You never want to load a breaker more than say,80% capacity.

IMHO the answer is YES as you are saying its a dedicated breaker serving only those 2 ballasts. then start up would hit 18 amps and go down with mag ballasts and even lower with digitals. and im talking HPS with MH start up lower.

[Snagglepuss]

just the ballasts with no fans or aything else?Probably not..Check and see hw many amps each one draws...The most i can run is a 600 or 400 on each 20 amp plus fans or a/c.And im most certain ,im pushing it...1000 plus the fans or a/c pops the breaker..

[rives]

Nope. With ballast losses, you are going to be pulling in the neighborhood of 2120 watts total. On 120v, that is going to result in a loading of 17.7 amps. Code stipulates that for a continuous load (anything exceeding 3 hours duration), you should not exceed 80% of the breaker rating, so in this case you shouldn't be going over 16 amps.

i've done it but in canada and 10 gauge wiring from the fusebox to the lightboard; and thus 2 - 1000w HPS hortilux. had too when my 220/240 power blew. 15 amp will not do but a 20 amp will.

i ran 4 - 1000w's on a 40 amp breaker too

[VIganjafarmer]

thanks for your replies very helpful....I wont run both lights off one, Im going to split the lights onto two breakers with 20amps each.

[rives]

Good choice, VIganjafarmer

Originally Posted by astra007

i've done it but in canada and 10 gauge wiring from the fusebox to the lightboard; and thus 2 - 1000w HPS hortilux. had too when my 220/240 power blew. 15 amp will not do but a 20 amp will.

i ran 4 - 1000w's on a 40 amp breaker too

Astra, this obviously falls under the decision tree on the side of "can I get away with it" vs. "is it a good idea". As your experience shows, it is something that will usually work and I wouldn't hesitate to do it to get around some catastrophe. On the other hand, if you are planning a new installation and considering doing it this way, it is a very poor idea. As I stated above, it doesn't comply with the NEC and can lead to both nuisance-tripping of the breaker and overheated wiring. You had over-sized wire installed, which I can guarantee you is not the case in 99% of residential installations. If the breaker is in an area where there is high ambient heat, or if the breaker is marginal, then you may find your lights off when you really don't want them to be. Complying with the code assures you that your installation is both safe and trouble-free.

i beg to differ as your initial start up will spike 9 amps and then drop to a lower pull. check the power ratings on the hortilux 1000w, i also have a pulse start up so that NOT all the lights fire up at the same time or you can install a dimmer switch to power up and then raise it to full power. never had a problem and never had an inspection of any kind. oh, and i grow in a trailor park on 100 amp service 120v and "hot legs" 240v power.


just to be on the safe side i had the 2 rooms on separate 220v power and ran 1 on a 30 amp and the other on 40 amps to power 6 - 1000w. 4 HPS and 2 MH. havent posted much lately, just lurked as i usually get these kind of replies that im running unsafe, not up to code, ect....... sorry but im an outlaw grower inside and out with over 40 years growing experience.

[rives]

Well, I'm an electrician with over 30 years experience and it's fine for you to do whatever your "outlaw" inclinations tell you, but it is piss poor advice to be handing out. As I stated above, the running amperage of the lights will typically be around 17.7 amps, which exceeds the 16 amps allowable for a continuous load on a 20 amp breaker. Good luck.