PDA

View Full Version : MH timers


Aquattro
06-11-2002, 03:22 AM
Anyone know whether or not I can put timers on the output side of a MH ballast? My wiring makes it easier to do it this way.

smokinreefer
06-11-2002, 04:00 AM
do you mean on the cord between the ballast and the socket? sure you can but why? that would mean the ballast will be powered 24/7 no?

could you explain how you would have this wired, i am at a loss here, trying to imagine how this would be set up.

Aquattro
06-11-2002, 04:48 AM
I have 2 ballasts wired together (1 power in). I then have 2 cords going out, one to each socket. I've used a male/female combo as a cheap quick disconnect on the output side for each lamp. Being lazy (and having extra timers), I thought about putting timers on this side. The main power is still on a timer as well. The alternative is to take apart the housing and add a second power cord in (which non-lazy people would probably do!). Clear like mud?? :D

ruck'n'reefer
06-11-2002, 10:05 AM
Another problem may be running 2 timers in series, I think. Unless the second timer runs on a separate power supply.

StirCrazy
06-11-2002, 10:28 AM
Brad, we could add a second cable no problem, I'll stop by one night and take a look for you if you want.

Steve

Bryan
06-11-2002, 10:49 AM
I wouldn't, the voltage to the bulb is around 300 volts. Unless you have some specailly rated timer, you would surely damage the timer, fire etc.

Aquattro
06-11-2002, 01:06 PM
Originally posted by Bryan:
I wouldn't, the voltage to the bulb is around 300 volts. Unless you have some specailly rated timer, you would surely damage the timer, fire etc.<font size="2" face="Verdana, Helvetica, sans-serif">Ya, that was my concern. Guess I need to stop being lazy tongue.gif . I'll add a second cord. Thanks!

reefburnaby
06-11-2002, 11:52 PM
Hi,

Yah...I wouldn't recommend it. Actually, the problem isn't too bad if you switch it on once and leave running forever. The problem is that MH requires about 200V to 400V to start the arc...after which it drops to around 100V or so. So the initial voltage strike can cause arcing within your timer and cause a fire (like a sparkplug or arc welding...but not quite as dramatic). When the timer is off...the ballast will constantly try to start and hits the timer with 400V zaps because it thinks that the MH lost its arc and needs another zap. Of course, the MH lamp isn't there...so it will zap the timer...over and over and over again. Over time...this can become a problem if it is cheap timer.

- Victor.