Derating ?? High bay

[johnnyjb]

Hi would you hafta derate a switch if you were switching one high bay 250watt son light or two maybe

 

[RF Lighting]

Yes, as the high inrush current can and does weld swich contacts together, meaning you cant switch them off and the switch will have to be replaced.

I have seen 2no. 400w SONs weld a 10A swich shut.

I would always use 20AX rated switches.

 

[JohnD]

Back in Leeds, Rob?

 

[RF Lighting]

Yeah. I had a nice time in Ireland though

 

[Spark123]

You need to multiply the wattage of the lamps by a factor of 1.8 and divide by volts in order to get the design current, your switchgear also needs to be rated for an inductive load, think it is AC-5a.