208 or120v?

[bohl1076]

I have 9high bay 400w metal halide at a customers place. 5 on ckt 8 and 4 on ckt 10. circuit 8 is on a 25 amp breaker and is pulling 20.1 amps, and Keeps tripping, circuit 10 is drawing almost 13 amps, any ideas? I swaped the breakers (both on 25's) and so far it's holding but both are hot hot to the touch!, I thought of making 1 or more 208v, but thought I'd ask for more advice. The panel has no exta breaker space. HELP, please!

 

[abhishekbt]

Yes, you can make one more 208v and in my opinion it should not hurt. Does anyone else has some better solution for this?

 

[bohl1076]

My only concern was if any of the 2 breakers trip it will leave the 1 light half hot, but on the other and it should help balance the loads

 

[don_resqcapt19]

There is some type of issue with one or more of the fixtures or the wiring on circuit 8. Those fixtures are drawing an average of 5 amps each and the ones on circuit 10 are drawing an average of 3.75 amps each. What is the nameplate load per fixture? I would expect that the 3.75 is very close to the nameplate.

It is my opinion that if you make one or more of the fixtures 208 and leave the others 120, that 240.15 will require the use of a two pole common trip breaker.

 

[santerola]

Retrofit all nine to a pulse start 320w metal halide. This will decrease your load by 20%, as well as, increase your light levels

 

[sparkycoog]

My only concern was if any of the 2 breakers trip it will leave the 1 light half hot, but on the other and it should help balance the loads

I think this is more of an all or nothing situation where you would use a dedicated 2 pole breaker and you'd use much less power.

Right now for all the lights you're drawing 33 amps on a 120 volt system. So that's 3960VA which on a 208volt system would be about 19 amps. A 2 pole 25 amp breaker should handle that if the fuzzy math holds up.

 

[don_resqcapt19]

I think this is more of an all or nothing situation where you would use a dedicated 2 pole breaker and you'd use much less power.
...

There will be little change in the power use if you change the voltage. The current will be less but the voltage will be greater, power is voltage times current.

 

[sparkycoog]

There will be little change in the power use if you change the voltage. The current will be less but the voltage will be greater, power is voltage times current.

You are correct. I meant current.

 

[dhkane]

There is some type of issue with one or more of the fixtures or the wiring on circuit 8. Those fixtures are drawing an average of 5 amps each and the ones on circuit 10 are drawing an average of 3.75 amps each. What is the nameplate load per fixture? I would expect that the 3.75 is very close to the nameplate.

It is my opinion that if you make one or more of the fixtures 208 and leave the others 120, that 240.15 will require the use of a two pole common trip breaker.

I agree, somethings not right with circuit 8. Check your connections. You shouldn't be getting hot-hot with a 25A breaker.