Relay switching compact fluorescent lamp - Electronic Circuits Projects Diagrams Free

chchuah · 19th June 2009, 09:54 AM

I use a 10A/277VAC to control 10 CFL with 40W each and found that the life span of the relay is reduced tremendously. The contact of the relay is welded. There is no problem to use the relay to control halogen eventhough up to 1000W. What is causing this and any method to protect the relay contact from welded?

nike6 · 19th June 2009, 11:54 AM

you could mount a capacitor across the contacts, and also use a smaller relay to disconnect that capacitor after 1/2 second or so.

can't really say what capacity, for 10 tubes, maybe a few uF.

also I am not expert for energy electronics, but that is what I believe would be a helping. So it is just what i would try.

Diver300 · 19th June 2009, 03:53 PM

I think your problem comes from the turn-on surge, as the input capacitors on the CFLs charge up.

(I am surprised that it is worse than the tungsten lamp surges. They are quite bad as well)

If you fit a surge-guard NTC thermistor in series, the turn-on surge will be much less.

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19th June 2009, 09:54 AM	#1
chchuah	Relay switching compact fluorescent lamp I use a 10A/277VAC to control 10 CFL with 40W each and found that the life span of the relay is reduced tremendously. The contact of the relay is welded. There is no problem to use the relay to control halogen eventhough up to 1000W. What is causing this and any method to protect the relay contact from welded?

19th June 2009, 11:54 AM	#2
nike6	you could mount a capacitor across the contacts, and also use a smaller relay to disconnect that capacitor after 1/2 second or so. can't really say what capacity, for 10 tubes, maybe a few uF. also I am not expert for energy electronics, but that is what I believe would be a helping. So it is just what i would try.

19th June 2009, 03:53 PM	#3
Diver300	I think your problem comes from the turn-on surge, as the input capacitors on the CFLs charge up. (I am surprised that it is worse than the tungsten lamp surges. They are quite bad as well) If you fit a surge-guard NTC thermistor in series, the turn-on surge will be much less. __________________ http://nottheboss.wordpress.com/