Electrical Question/Calculation Related to Amps

[jj ocean]

I have (2) 400W metal halide lamps running on magnetic ballasts. How many amps are they going to pull? Anybody know if they draw more amps on startup and if so, how much more?

I'm running into issues tripping my house breaker or Apex EB8 breaker. They are running through the 10A mechanical outlet. I thought I had everything balanced right.

I don't think it matters, but the ballasts are Hamilton Technology Magnetic Ballasts for 400W & the bulbs are 400W Radiums. Thanks.

 

[rdnelson]

A 400 watt ballast will have some ballast laid in addition to the lamp. Therefore it should be calculated at 420 watts (or volt amps). Therefore each one would be 420/120=3.5 amps. Combined would be 7 amps for the two. Now if you have more items on those circuits you have to make sure you do not exceed the rating of the breaker.

At continuous duty (3 hours or more) a breaker will only hold 80% of its rating. So a 20 amp breaker will only hold 16 amps continuously.

Please don't make the mistake of increasing the breaker size without making sure the wire is sized properly.


ARC....so nerdy our President breaks bones while bowling.

 

[jj ocean]

rdnelson99;923846 wrote: Therefore each one would be 420/120=3.5 amps.

Thanks. My issue is that I have 15A circuits down in that area and just too much stuff on them. Between my chiller, MH and heaters, I'm tripping the circuits.

I have 3 dedicated outlets in my fish room for each of my EB8's. I got talked into putting them onto my existing breakers instead of just putting them on their own breakers in a separate subpanel (main panel is full). Obviously regretting it now. Running without MH right now.

Any electricians in the house? I just need to go ahead and put a sub panel in with 3 20A breakers for each of the 3 outlets. My main panel is in the fish room with each of the 3 outlets 2', 8' and 12' away respectively. Should be as simple as it gets. I'll pay with $, frags and/or beer. Just need to be licensed. I'm very handy, so I can pitch in - just not down with tapping into the main power myself. Let me know. Thanks

 

[rdnelson]

PM sent.


ARC....so nerdy our President breaks bones while bowling.