Ask Experts Questions for FREE Help !
Ask
    guyhood's Avatar
    guyhood Posts: 15, Reputation: 1
    New Member
     
    #1

    Feb 11, 2007, 02:19 PM
    Electrical & lighting
    How many 400 watt Halide Light fixtures should I put on a 20 amp 120 volt circuit. Four?
    Thanks, Guy
    Peter Kwan's Avatar
    Peter Kwan Posts: 26, Reputation: 1
    New Member
     
    #2

    Feb 11, 2007, 06:42 PM
    The 20 AMP breaker usually only rated about 80% of full capacity, therefore, the calculation is:

    20 amp * 120 V * .8 = 1920 Watt

    1920 /400 = 4.8

    You are correct.
    tkrussell's Avatar
    tkrussell Posts: 9,659, Reputation: 725
    Uber Member
     
    #3

    Feb 12, 2007, 03:38 AM
    Need to be aware that a 400 watt Metal Halide fixture draws more than 400 watts, anywhere from 430 to 480 watts, due to the ballast load. So better to use the rated amperage draw of each fixture to calculate how many fixtures on a circuit.

    With the four you have still fits on a circuit, even at 480 watts each, just be aware of the total load if more are needed.

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Electrical lighting [ 1 Answers ]

Hello I put a low wattage light into a porch light which is on a 2 way switch. Every 5 seconds the bulb flickered when the light was switched off Does anyone have any idease why this might be happening Thank you

Lighting/electrical - is separate circuit possible? [ 3 Answers ]

I have lights in my house that have both a regular switch and a dimmer switch. A few days ago I used the regular switch to turn on the lights and it looked like a circuit breaker tripped and the lights went out. I checked the main box and no circuits were tripped... and I looked for a sub-panel...

Electrical & Lighting [ 1 Answers ]

I have a Hampton Bay St. Regis ceiling fan but no directions. Can I get a copy?

Electrical & Lighting [ 1 Answers ]

I have a Hampton Bay St. Regis ceiling fan but no directions. Can I get a copy?


View more questions Search