MH bulb does not ignite.

[kebnekajse]

Newly purchased. Use it with a GIB- ballast, 250w. It works perfectly most of the time, but it has to be cold to ignite. I have to shut it off everytime i open my cab for various reasons, and when i want to put it back on the ballast just makes these small noises (tk-tk-tk-tk, sort of). If i wait a minute or two it ignites as usuall.

I know heat makes the resistance go up, could this be the problem? Does anyone recognise this? It's a bit annoying.

Another strange thing that differs from when i use a hps: I switch on/off with a knob on my powerstrip. But, when this strange thing happens, it draws power for a few seconds before it's out (the knob is lit for a few seconds after it's turned off and after the strange sound stops). My guess it's a condensor, normal behaviour. But when i switch off the lamp when it's functioning well it does not behave like this. Anyone know hat this is?

 

[Budders Keeper]

You must leave Mh ballasts off till cool before re-igniting(usually 15 min.). This is normal.

 

[kebnekajse]

Thanks, good to hear it's normal. 15 min might be for more powerfull ballasts, 1-2 min is enough for me.

I'm reliefed.

k

 

[DonJones]

Actually it isn't the ballast that needs to cool down, it is the bulb. If you have a second bulb available that is cool, you can shut the light down, unscrew the hot bulb very carefully, screw the cool one in and immediately restart the ballast and it will start and run normally.

I believe it is the same for all HID type lights and mercury vapor too. I'm not sure about the halogens.

 

[leafminer]

Yeah that's right. The arc won't re-strike until the vapour pressure inside the bulb has dropped sufficiently.

 

[balorevileye]

Another strange thing that differs from when i use a hps: I switch on/off with a knob on my powerstrip. But, when this strange thing happens, it draws power for a few seconds before it's out (the knob is lit for a few seconds after it's turned off and after the strange sound stops). My guess it's a condensor, normal behaviour. But when i switch off the lamp when it's functioning well it does not behave like this. Anyone know hat this is?

If i get what your saying then its the capacitor discharging itself which provides enough energy for a few seconds of light from the led indicator, the smaller wattage the bulb the longer they stay on due to having a smaller need for current which is available from the discharging capacitor. if it doesnt happen when the lamp is switched off and the strip is then switched off by you then thats because by turning the lamp off its discharging internally and the circuit is broken going back to the strip so the led indicator isnt lit then because theres no current available. hope that helps

 

[RiskyPack]

I'll tell you KK I was so disappointed with my MH bulb when I plugged it in.. My HPS is normally at full strength after 30 seconds, but the MH bulb took nearly 2 minutes, and I just got blinded.. I think everything is just a bit slower with MH, but the results for vegging is staggering