Metal Halides And Timmers

[adambrum]

Bit of a tecky question but i need to switch 150w halides by a timer but i know a normal timer will work but its not safe and it can damage my lights so the way i see it i have three choices,

1. use a contactor a bit over kill ( 16A n/o 240v coil using 2 plugs, 1 for timer 1 for power)

2. power relay 10A ( same set up as above)

3. use a timer for immersion heaters ( 13A resistive 6a passive used on its own)

I think the lights need to rated for passive load but im not sure can anyone help me out here and everyone else who is switching halides

P.S. I know i can buy the first option but why buy what will cost less than half to build

 

[bobf]

I went through this same dilemma some time ago - posted on here about it.

Upshot seemed to be that most folks took the view that a regular mechanical (moving wheel and pins) type timer would be okay. Evidently the initial current draw isn't as overwhelming as some light manufacturers would have you believe - one or two of the kind folks on here quoted numbers if I recall? (Ski/Lynden?)

I went with a timer of that type running twin 150w halides and another for twin actinics about 6 months ago and it hasn't missed a beat. Obviously not saying perfect solution for every circumstance but seems okay for me.

 

[drag]

id check the amps the halides pull if its less than 8 amps ( it more than likely is) i would use an ice cube relay (power relay).

 

[SkiFletch]

A 150watt metal halide ballast will GENERALLY have an operating current of 1.5A continuous and not much more than 2A for a millisecond at startup in the US. If in the UK, halve those values. 150s really dont require special equipmet. I run a mechanical timer on my 175watter, no problems. Its really not till you get into the 400 or 1000watt ranges that you have to worry.

Do make SURE you get a mechanical that is grounded though for safety purposes

 

[andywg]

I have no problems with my 150W halides on mechanical or digital starters.

All my T5 and other flourescants, however, do seem to destroy timers, either resetting digital ones, or causing problems with the mechanics of the mechanical ones (such as not turning off or progressing at 1/4 time).

 

[Miss Wiggle]

our 250w mh destroyed a mechanical timer, we do it by hand now cos we're lazy and haven't got round to getting a new timer for it yet

 

[adambrum]

I think just to be on the safe side im going with the power relay and a timmer, going to use a octal base relay same as used in machines as i have never had one fail even in machines 20 years old ! and there cheap as chips.

will post pic when done