Mercury Vapour Bulbs - why no thermostat?

[Grunter023]

Hey, I heard that you should not put a Mercury Vapour Bulb on a thermostat at all. Just wondering why? I am guessing it has something to do with the filament in the bulb not liking thermostats turning on/off or dimming etc, thus blowing the bulbs maybe. I currently have a MVB set up to a IMIT thermostat as a temp housing for the next day or so (probe is in a position that it should never get to be turned off by the thermostat). Also wondering if you can mess about with a IMIT thermostat to never turn off without me having to muck about with electrical wires, or should I just be done with the IMIT and remove it completely? Trouble is it already wired up into the enclosure I bought. Cheers.

 

[mike72]

That's right, the globes are not designed to be turned on and off too frequently. If I was you, i would leave the thermostat in but add an additional, sperate light fitting for the MVB that is not run through the thermostat. That way you can still use the thermostat for IR or ceramic globes for night time heat or for an extra boost an really cold days and still use the MVB for your UV and primary day time heat. You will just have to keep an eye on the maximum temperature inside the unit during the hot days of summer to make sure the MVB does not get the unit too hot, it may be that on really hot summer days (35+) you are better off not turning on the MVB at all.

 

[cridon96]

I have run one of these on a thermostat over a long period i know they are not designed for it but was in a large tank so was on most of the time I did however keep the thermostat conected to avoid over heating if you set it to the top end temp it acts as a fail safe if the enclosure over heats.

I do however think it is good to have a ceramic in there for night and have the mercury vapour on a timer to be on only during the day

 

[Grunter023]

Great thanks for sharing your experiences/views. I have two MVB's right now and they are for a pair of Ackies (which should be fine without a thermostat you would think as they like it hot) and the second is for a pair of Beardies which will hopefully be housed outside in summer when it could normally get to hot for them without a thermostat inside and a MVB.

 

[Sigman21]

u could use a dimming thermostat and that would never switch your globe off? just an idea

cheers, dean

 

[Bushfire]

A dimming thermostat is also no good as the globes are designed to operate at the full voltage. By lowing the voltage the globes wont operate properly. When I had MVBs I would control the temp by the distance it is positioned from the basking spot. Generally speaking with my monitors I was getting 70oC when the globe was about 12cm from the basking site. The thing that stopped me using MVBs was that this distance the UV levels were dangerously high. They recommend a min distance of 30 cm which at that distance I was getting temps of only 32oC.

 

[Grunter023]

Buy Mercury Vapour Lamp, CFL Lamps, Halogen Globes, and All Other Lighting Supplies Online from Esidirect. We have a Massive Range of Lighting Supplies Available for Fast Delivery Anywhere in Australia would these bulbs be ok to use for a MVB? They seem a bit cheaper and nasty to me

 

[lloydy]

You need to make sure the MVB's that you use producr both UVA and UVB.

The bulb in the link above is a household bulb, i think?