28 pcs. of metal hallide lamp at 70 watts using 12 awg THHN ..how many circuits i do?

Question

28 pcs. of metal hallide lamp at 70 watts using 12 awg THHN ..how many circuits i do?

Answer 1

If your supply is 120 volts AC at 15 amps per circuit, you would need 2 circuits. What voltage you use, and the amperage rating of the supply will ultimately decide for you how many circuits that you will need. If the circuit is fed by 220 volts AC, then a single 15 amp circuit would do just fine.

A point to remember, multiply the number of devices by the wattage each one uses. From there figure the voltage each device uses, and the number of amps each lamp needs. Add in at least 10% as a safety factor, and add all of the individual amp requirements together. That will tell you very quickly just how many circuits that you need. For my opening response, 14 devices at 70 watts each will draw 980 watts. That is about half of the capacity of a 15 amp, 120 volt AC circuit. That leaves room for surge, component changes, and some expansion if it is needed.

Answer 2

Arithmetically slamma's answer is right but there is another factor. You would want to have lamps in a given room on different circuits so that if the breaker pops on one circuit there is still enough illumination in a room that you can safely leave the room without stumbling over something in the dark.

Answer 3

At 12 Volts, 24 Volts, 110 V, 240 V?

Answer 4

Consult the wiring codes for your area.

Would you really build it from directions you get on this forum? I hope not!

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Answer 5

At 120 V  it's 16.33 amps , but you also have to allow for distance , so i would say 2  - 20 amp circuits. if the distance is not that great.