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  • Source Four HID Current Draw

    Questions:

    What is the current draw for HID fixtures?

    What is the inrush current?

    How many fixtures can I put on a circuit?

    Answers:

    HID inrush can draw upwards of 18-20 amps on a 120V service.  This inrush current only lasts for a very small fraction of a second.  Its duration is too short a time to trip breakers. 

    The normal operating current draw for a 150W fixture is 1.4A at 120V and 1.85A for 277V.  A 70W fixture will draw .7A at 120V and .3A at 277V.

    For a 20A breaker:

    ETC's recommendation is no more than ten (10) 150W HID instruments on a 20A, 120V service and no more than fifteen (15) 150W instruments on a 20A, 277V service.   For 70W HID instruments, ETC recommends no more than fifteen (15) units on a 20A, 120V service, and no more than twenty (20) units on a 20A, 277V service.

    For a 15A breaker:

    ETC's recommendation is no more than seven (7) 150W HID instruments on a 15A, 120V service and no more than ten (10) 150W instruments on a 20A, 277V service.   For 70W HID instruments, ETC recommends no more than ten (10) units on a 20A, 120V service, and no more than fifteen (15) units on a 20A, 277V service.