Dimmer switches - has anybody had success?

[peter120886]

I know this topic has had a fair amount of coverage already, but I reckon most of the threads were based on "I've heard you can do this" or "I saw somebody use this"... not really first-hand information. So my questions are as follows;
1. Has anybody succesfully used a dimmer to control a heat-pad?
2. Is there a specific type of dimmer that needs to be used, with regards to load etc... my heat-pads are only 14w.
3. If the switch were to fail, would it fail "on" or "off"?

[kfc223]

Well I've never risked it.

But everything that I've herd says when the switch fails it fails similar to the old heat rocks that used to be used for snakes and lizards.

I would rather suggest to get a analog thermostat.

You can order one online for R250 from reptile city.

[terra-nova]

I agree with kfc223,I wouldn't risk it...rather pay that bit extra now than be sorry later!

[ClintonT]

Hi Peter,

Like the previous comments, the dimmers can be used but I would look at building in an additional fail safe option to prevent disaster should you wish to use it as opposed to standard on/off heat control.

I use the dimmer option in this setup:



The dimmer provides what I refer to as a poorman's proportional control to the heat pad. The digital controller monitors temperature shuts off supply once high point is reached. This also prevents overheating in the event the dimmer fails.

Regards
Clinton

[peter120886]

Thanks Clinton. Going on the responses thus far I am probably going to "bite the bullet" and go for an ATC 300, does anybody know if this controller can be used to run more than one heat pad? reason for asking is that my enclosures are all the same, 800x390x400 melamine, so although the controller only has one probe input, with the same wattage heat pads in each enclosure I would imagine that temps would stay pretty similar?

[Athlordian]

Hi peter120886,

I had a quick look at the specs on the ATC 300 controller and it looks like it can safely handle a controlling load of 1200W. That equates to roughly 85 14w heatpads. However, with that said, I wouldn't push it to its limit. Rather safe than sorry and all that other precautionary stuff...you know.


Here's a link to the specs: http://www.reefdreams.co.uk/acatalog/ATC-300-2-CHANNEL-HEATER-TEMPERATURE-CONTROLLER-WITH-TIMER.html

I hope this helps.

[peter120886]

Thanks Athlordian, that is a very helpful link! I didn't realize it was that powerful! Only in my wildest dreams would I need to control 85 heat pads. This thing could theoretically control an entire snake room! And it has a timer output... I am definately goin to get one, at the price it seems like an investment rather than an expense. Thanks for the input all. This is a link to the controller at ReptileCity http://www.reptilecity.co.za/catalog/pr ... cts_id=846