Socket Timer For Metal Halide?

[BigIan]

has any one found a socket timer that won`t burn out with a metal halide?

 

[andywg]

I have a £7 digital timer that always reset it self when running 36W T8s, but has run 2 150W MH fine for a long time, and currently runs 1 150W MH. I plan to use it for both 250W lights once I get the internals.

Any timer will run MH if you buy a contactor for them. I don't think it is that expensive either from ebay.

 

[BigIan]

thanks andy, think i`m going 5to invest in a digital one,
and what is a contactor???

 

[andywg]

Now I am not great on this, but my understanding is:

It's a relay which prevents the power necessary to start up the ballast from melting the insides of the timer circuits.

 

[BINKSY]

yes you are on the right lines Andy. A contactor is basically a set of contacts which are open and closed by a coil. IE in your instance Ian you would wire up the timer to the coil, you then need a permanent supply on one side of the contacts, then the lighting connects to the opposite side of the contacts, so when the timer switches on it operates the coil which closes the contacts and makes the circuit, with this method you can switch on and off big loads without the need off massive switches. But please note you still need the required size cable to feed the contacts and the output load.



Cheers Gordon

 

[BigIan]

yes you are on the right lines Andy. A contactor is basically a set of contacts which are open and closed by a coil. IE in your instance Ian you would wire up the timer to the coil, you then need a permanent supply on one side of the contacts, then the lighting connects to the opposite side of the contacts, so when the timer switches on it operates the coil which closes the contacts and makes the circuit, with this method you can switch on and off big loads without the need off massive switches. But please note you still need the required size cable to feed the contacts and the output load.



Cheers Gordon

yeay i understood that....

NOT

 

[SkiFletch]

Lol, a contactor is the electrician's short name for a mechanical magnetic coil relay. Like andy said they protect the timer internals from the high current used by the lights. It essentially has two sides, one for control voltage, and the other for operating voltage. You wire the operating voltage side in-line with the hot or cold of the AC supply to the ballast. Then you wire the control voltage side in-line with the hot or cold of the output of the timer. Complete both circuits back to their source and you're set.

Then when the timer turns "on" it supplys voltage to the control side of the contactor. Immidiately thereafter (within milliseconds) the magnetic coil closes the contactor and allows current to flow to the ballast, thus powering the light. Hard to comprehend if you're not into wiring but it's really quite simple.

TBH, I'm surprised you UK guys have so much trouble with your timers. I run a cheap $10 mechanical dial style timer for the past year with no troubles. Either they make them different on opposite sides of the "pond" or somthing about the 220V control dos something I dont understand...

 

[adambrum]

Its an old post but i have found a great timmer for the UK and there from B&Q of all places, there not stated as to what they are on the box but if you check online there rated for twice as much as normal timmers.

here is the page, timer the bit your looking at is the 13A resistive load/4A inductive load/240V bit, normal timers are rated at 2A inductive which is the bit that kills normal timmers.