Can anyone tell me if its safe to use a standard mechanical timer to turn on and off a set of 2x250W Metal Halide lamps ? ive heard some people say they need a contactor ?
Metal halide on a timer
- Thread starter steven0161
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Most time clocks are designed for resistive loads - standard Immersion ones certainly are.
Look for the rating on the timer, it may give you an indication of it's maximum inductive rating. Other than that, yes, a contactor (switched by the timer) would be the way forward. Check you get a contactor suitable for the inductive load
Look for the AC rating (AC1, AC3). AC1 is light inductive loads (a few flourescents), AC3 is fairly high inductive loads (motors etc).
Look for the rating on the timer, it may give you an indication of it's maximum inductive rating. Other than that, yes, a contactor (switched by the timer) would be the way forward. Check you get a contactor suitable for the inductive load
Look for the AC rating (AC1, AC3). AC1 is light inductive loads (a few flourescents), AC3 is fairly high inductive loads (motors etc).
IMHO, when ever we have to time switch these, we Always get the timeclock to switch a relay or contactor, easier to replace an octal relay than the timeswitch!
Only time switch that I know that would switch this is the old Samgamo round mechanical ones, even then, be prepared for a blue fireworks display when it changes over!
Only time switch that I know that would switch this is the old Samgamo round mechanical ones, even then, be prepared for a blue fireworks display when it changes over!
some timers available can handle 10a resistive/inductive loads,pricey though
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yes you will need a contactor
If it was 150w metal halides you wouldnt need one and could get a way with a timer.
the load from a 250w when switched on will cause the timer to arc (? i think thats the correct terminology)
This is something i have read alot on (use 2 * 150w for fish tank)
If your looking for a contactor check out [url]http://www.marine-lighting.co.uk/ [/url] click on the bottom right hand side
If it was 150w metal halides you wouldnt need one and could get a way with a timer.
the load from a 250w when switched on will cause the timer to arc (? i think thats the correct terminology)
This is something i have read alot on (use 2 * 150w for fish tank)
If your looking for a contactor check out [url]http://www.marine-lighting.co.uk/ [/url] click on the bottom right hand side
I dont think you will find a true contactor in that enclosure either - more like a relay
crafty1289 said:
Funeral palour?
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Are you using a timer on its own or in combination with a photocell, certainly a contactor would be the best method, or as gingervit suggests a sangamo timer with the solardial feature which compensates for changing sunrise/sunset time
B
breezer
fattony said:
as was said , us regulars know, you dont want to go there, trust me
Now I cringe when anyone says "I built it myself"
Also see:
//www.diynot.com/forums/viewtopic.php?t=37455&highlight=
Also see:
//www.diynot.com/forums/viewtopic.php?t=37455&highlight=
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