chimera Posted September 19, 2004 Report Share Posted September 19, 2004 What brand/type of timer does everyone use to turn their lights on/off? Since i've got the M/H's, I've blown up 2 x timers. They were both HPM digital timers from Dick Smith. The digital display and everything still works, it's just now that the lights never turn off. Even if I manually push the "mode" button to change from Auto to Off, the lights still stay on. These worked fine with my fluoro's so can only assume the MHs have shagged them. Are these timers not rated for massive wattage or something? Quote Link to comment Share on other sites More sharing options...
jetskisteve Posted September 19, 2004 Report Share Posted September 19, 2004 I use the HPM ones but my M/H's are only 150w & they work great. On the Taka tank I run HPM but 250w M/H & same prob as you when halides start up they draw huge current, jump in here Layton Quote Link to comment Share on other sites More sharing options...
lduncan Posted September 19, 2004 Report Share Posted September 19, 2004 yeah If your using magnetic ballasts, the inrush current when you first turn on the switch can be up over 10 times the running current. In my case it's up around 60 amps! This is what would be screwing your timers. The relay contacts are arcing over when switching and melting the copper contacts closed. I've never had this happened to me. I use cheap digital timers from place makers (don't know the brand). If it's a continual problem try separating each bulb onto it's own timer. Layton Quote Link to comment Share on other sites More sharing options...
chimera Posted September 19, 2004 Author Report Share Posted September 19, 2004 good plan re: seperate timer for each, will try that. cheers. Quote Link to comment Share on other sites More sharing options...
lduncan Posted September 19, 2004 Report Share Posted September 19, 2004 Are you running 250's or 400's? I got two 400's on a single timer, so maybe try a different brand timer. Layton Quote Link to comment Share on other sites More sharing options...
reef Posted September 19, 2004 Report Share Posted September 19, 2004 his running 250w. Quote Link to comment Share on other sites More sharing options...
reef Posted September 19, 2004 Report Share Posted September 19, 2004 You need to have thermal cut-out in the ballasts. This are thermal resetting switches in the windings. The problem is that High Intensity lamps (includes MH) suffers from rectification towards the end of life. Theoretically this can also happen prematurely in lamp but very rare. This process will draw more and more DC component of the current which the ballast is not able to stop. But this will still have the effect of increasing ballast winding temperatures. Ultimately the insulation in the winding breaks down and shortcircuits causing arcing and possible fire as the worst case scenario. In some cases the incresed current is enough to create increased pressure in arc tube in a lamp causing it to explode. Quote Link to comment Share on other sites More sharing options...
RnB Posted September 19, 2004 Report Share Posted September 19, 2004 you can buy a contacter that will take the input from the timer, and use that to switch the MH on/off... about $70-80 from ideal electrical, you still need a timer tho to trigger them. Quote Link to comment Share on other sites More sharing options...
lduncan Posted September 19, 2004 Report Share Posted September 19, 2004 My timer is an "Altona" rated for 2400W, I got it at Placemakers about 3 years ago. See if you can track one down from there maybe. Layton Quote Link to comment Share on other sites More sharing options...
reef Posted September 19, 2004 Report Share Posted September 19, 2004 Sounds like a job for DIY rescue Quote Link to comment Share on other sites More sharing options...
chimera Posted September 19, 2004 Author Report Share Posted September 19, 2004 yes, as reef said 2 x 250W. my timer is an HPM, rated for 2400W... still blows up... pos. Quote Link to comment Share on other sites More sharing options...
Pies Posted September 20, 2004 Report Share Posted September 20, 2004 This is a common problem on RC as well, but normally associated with 400watters and the inrush current issue. 1 timer per light seems to work, but serach reef central for models that are known good. The guy from UR (the guy Mark that NickS met in the UK - 7000litre) had major issues as he didn't know his timers had broken and his tank lights where never turning off. His tank was crashing and he couldn't figure it out. But that was the cause. Search on 7000litre on UR to find the thread. I am moving to 400s soon so am keen for anyones reccomendations. Piemania. Quote Link to comment Share on other sites More sharing options...
lduncan Posted September 20, 2004 Report Share Posted September 20, 2004 yes, as reef said 2 x 250W. my timer is an HPM, rated for 2400W... still blows up... pos. It's not really about what they are "rated" for, it comes down to the quality of the relay used. Different brands will use different relays. Layton Quote Link to comment Share on other sites More sharing options...
chimera Posted September 20, 2004 Author Report Share Posted September 20, 2004 and here i was thinking hpm were good... Quote Link to comment Share on other sites More sharing options...
RnB Posted September 20, 2004 Report Share Posted September 20, 2004 pies... go to ideal electrical on wakefield st explain the inrush ammount, the contacter must use relays capable of that current..... the trigger current is negliable..... in fact you can buy contacters that trigger on 12 v dc or ac or 240v ac. you need the 240v ac type if you are going to use standard cheap timers. spent 3 years at uni on this stuff.... it will work, its what it is designed for....... lots of spa motors etc use these to off load the switching from the timer... while you there take a look at the industrial timer units... about $220 tho for a 2 channel unit...... Quote Link to comment Share on other sites More sharing options...
petplanet Posted September 20, 2004 Report Share Posted September 20, 2004 I use the cheap nasty timers with 1 on pin and 1 off pin - no problems and they cost less than $20.00. The HPM digitals that I had lasted less than 6 months. Quote Link to comment Share on other sites More sharing options...
Ira Posted September 20, 2004 Report Share Posted September 20, 2004 I bought 2 of them, I guess HPM ones, from dick smith, digital ones anyway. Neither of them would keep the time and settings! Quote Link to comment Share on other sites More sharing options...
Ira Posted September 21, 2004 Report Share Posted September 21, 2004 Ok, the ones I was thinking of WEREN'T HPM ones. But guess what! The HPM one had decided it didn't want to turn off when I got home from work this morning. It wouldn't even turn off manually. I took it apart, the contacts didn't seem to be welded closed, so I'm not sure what the problem is. It looked like there's a flat metal bar that snaps back and forth to turn it on and off. That bit had shifted a little so that it wouldn't turn off again. I THINK that's it, assuming I didn't do that while disassembling it. Unfortunately, after reassembling it, it doesn't turn like it's supposed to so it's still busted. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 24, 2004 Author Report Share Posted September 24, 2004 I just bought a 240V 4 pot relay to switch my hallides on with. Neutral and earth will be permanantely connected and phase will be switched on and off through the relay via an HPM digital timer. I wanted to continue using the digital timer as it has battery backup to maintain time and settings if the power goes off (rather than the analog/pin style) Hooking up this weekend so will let you know how it goes Quote Link to comment Share on other sites More sharing options...
chimera Posted September 25, 2004 Author Report Share Posted September 25, 2004 Well a mate and I wired up a solution for this today using the relay as above. I wanted 4 outputs (to run 2 x MH's and 2 x actinic blue T5's - yet to get) There are 2 inputs into this unit. One provides the power to the relay and the other switches it on/off via the timer. Here's the pic. Am going to make a box for it tomorrow to seal it. I have tested it and it works very well. A little more expensive than ya average analog timer but at least it has battery backup from the HPM digital and regulates the voltage across 4 outputs all of which are able to be individually powered on/off. Starting to assemble: Complete: The white wire provides power to the lights. The green wire comes from the timer and switches the relay (thus "white wired" lights) on/off. Quote Link to comment Share on other sites More sharing options...
chimera Posted September 26, 2004 Author Report Share Posted September 26, 2004 Box is complete, all powered up and tested. Works a treat. Going to mount this on the wall soon (as soon as I put some new ply up) I also got the moonlight going tonight too. Very effective! Post some pic's of that later. Quote Link to comment Share on other sites More sharing options...
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