# can i plug a heat mat & ceramic heater to one pulse stat



## reptile1 (Jan 25, 2008)

just what it says cheers


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## Ssthisto (Aug 31, 2006)

Unless they're *exactly* the same wattage I wouldn't.

Either the heat mat will be supplied with too much power to keep IT a steady temperature or the ceramic may be supplied with too low an amount of power to keep it running, depending on where you site your probe.


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## fixitsan (Apr 15, 2008)

reptile1 said:


> just what it says cheers


Yes, if you add the wattage of each device together to make sure it does not exceed the rating of the pulse stat.

The question is where to put the temperature probe ?
If you put the probe in the air away from the mat and at the coolest end of the tank then not only will the ceramic lamp be forced into emmitting a lot of power to raise the temperature, so will the mat too. If the mat is in the tank to act as a basking spot then it will get pretty hot. If the mat is on the back wall then it is not so important how hot it gets there.

In short, yes yoiu can run several heaters from one stat, but make sure that gaurd against hotspots by putting the probe aomewhere where it will control the heat of the heater which is potentially the most dangerous to the pet should it get too.

Chris


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## fixitsan (Apr 15, 2008)

Ssthisto said:


> Unless they're *exactly* the same wattage I wouldn't.
> 
> .


I don't want to be pedantic but what difference is there if you run a 25W mat with a 100W ceramic, to running a 50W mat and a 50W ceramic ? Neither of them are going to be damaged in either case.

The only thing to be wary of is that the basking spot should get the probe because that is the primary concern, just as it probably always was


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## HadesDragons (Jun 30, 2007)

fixitsan said:


> I don't want to be pedantic but what difference is there if you run a 25W mat with a 100W ceramic, to running a 50W mat and a 50W ceramic ? Neither of them are going to be damaged in either case.
> 
> The only thing to be wary of is that the basking spot should get the probe because that is the primary concern, just as it probably always was


Out of interest, does that only apply to mat (on / off) and pulse stats (again, basically an on / off, just with faster switching). If you were going to use two bulbs on a single dimmer stat would they have to be the same wattage?


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## fixitsan (Apr 15, 2008)

HadesDragons said:


> Out of interest, does that only apply to mat (on / off) and pulse stats (again, basically an on / off, just with faster switching). If you were going to use two bulbs on a single dimmer stat would they have to be the same wattage?



Yes it is the same.
Two dissimilar bulbs on one dimmer isn't a problem as far as the controller is concerned.

Controllers switch the 240Vac supply on and off, so as long as your heating devices are all rated for 240V so even at 100% power output the will just be connected to the mains the same as before.

I just have to stress that you need to consider the position of the probe as being the most important thing here.

Here's an exagerated example of why probe position is important.

Say you have a mat and a ceramic lamp and you have placed the probe on the mat, and youv'e cut a few corners to squeeze the ceramic lamp into a tight space with the promise that you will never turn it up to full power or it will overheat.
If you connect that ceramic heater to the same controller as a mat and switch everything on from a cold start, the mat and the heater will receive full power until the mat tells the probe it is getting close to operating temperature.
In such a situation as a cold start situation all heaters will get full power
and so it's much more important to have the lamps and heaters outside of the tank or very well guarded.
I suppose that nobody would put their animal into a completely cold viv but if you open the door and let the heat out and the temperature keeps dropping a similar thing can occur as happened with the cold start.
As long as each device can be powered up to full power for a few minutes at least then you are completely safe.
The controller adds the power requirement of the loads together and considers it all as just one single load.


The probe should be placed in the hottest part of the viv, which you would find with a thermometer and a bit of patience. Then you will know that the controller is controlling the maximum temperature in the viv at all times.


Chris


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## tina b (Oct 3, 2007)

i run 4 x 100 watt and 1 x 60w bulbs on a 600w stat with no probs at all the viv with the 60 bulb has to be quite a bit lower temps than the vivs with the 100s in so this works great for me...


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## fixitsan (Apr 15, 2008)

tina b said:


> i run 4 x 100 watt and 1 x 60w bulbs on a 600w stat with no probs at all the viv with the 60 bulb has to be quite a bit lower temps than the vivs with the 100s in so this works great for me...



I don't think it will always be safe to do as you're doing here.

My cheif concern is that you have a probe in one viv which is run off a controller which is providing power to another viv. What I'm thinking about is what if the heater in the viv which has the probe in it fails ? 

Normally the controller will immediately attempt to increase the power output once it senses the temperature drop caused by the failed heater. In turn it will also increase the power output to the other vivs, and where those other vivs and all of a sudden they see a large increase in temperature as the probe and controller try to raise the temperature in the first viv.

Unless the probed viv comes up to temperature, and it could only do that if it had multiple heat sources in that tank, then the controller will eventually set itself for maximum power output as it tries to compensate and all the other tanks get maximum power too.

I would normally only consider one probe in each viv unless the probed viv had redundant backup heating, so I think if this is something which more people are going to try then unless you have two heat lamps instead of one, you could find one day that the main heater has failed and all the other heaters attached to it (which don't have a probe near them) are running at 100% power.

This is differnt to driving more than one heater from a single controller, in the same tank, which generally speaking is very safe

Chris


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