low bay lights

[Welshsparky]

Hi I have 4 , 400 watt low bay lights , on 2.5 , 16 amp breaker, will I need,a contactor?

 

[Welshsparky]

Metal halide. May I add

 

[Richard Burns]

If they are all switched on simultaneously then the initial current draw may trip the breaker (but I would not have thought so for four lamps) you might be OK, might be worth using a 16A C type if you can meet the Zs, though a contactor would overcome this.

 

[i=p/u]

isit not the multiply 400x4 by 1.8= 2880/230 =12A, less if you knoow the facors from data

 

[Darkwood]

referencing tech data from square D .... 16amp (c) = 2 x 400w metal hallides
(d) = 4 x 400w metal hallides

Again Zs would have to comply and these rating usually apply across the board with different brands, when designing lighting circuits its always best to work backwards in that find out first the max recommended by tech for mcb you wish to use, these figures are taken for a circuit with upto 20m run to first light then 7m between lights.
Doing as you've done even with contactors will probably be prone to nuisance tripping from the accumulative in-rush of 4 lamps.