Re: Temp. controlled DIY heat cables
To: aquatic-plants at actwin_com
Subject: Re: Temp. controlled DIY heat cables
From: "shaji (s.) bhaskar" <bhaskar at bnr_ca>
Date: Wed, 26 Apr 1995 18:17:00 -0400
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>I am working on building a set of DIY cables for my 55 and was looking for a
>way to improve the recommended low wattage design that is so common. I
>figured that the ideal is to have the cables provide all the heating in the
>tank, thus maximizing the convective flow and warmth of the substrate. My
>plan is to take a 300 Watt Otto compu-therm heater and hook the supply for
>the transformer up to the control box instead of the otto heater. Voila,
>instant probe and controller. The cost of it is $30.00, which is less than
>I would have paid for another heater to make up the difference in the
>required wattage and a timer to control the intervals on the cables (if it
>would have ended up being necessary).
>Has anyone tried this? Is there any reason why this wouldn't work?
I don't know if the controller is capable of handling the inductance
of the transformer. It is possible that the controller will be damaged.
A high-power tansformer that delivers 200+ watts at 24 volts will be
expensive. The cost will be above $100, even if you order through the
mail. You may be able to pick one up for a reasonable cost at an
Also, a high-wattage substrate heater will remain off during the
summer, depending on where you live. A low-wattage system could be
left in operation year-round.
>It seems like I am not the only one looking for suitable cables to use. I
>was looking at the cables designed to melt ice off of the eves of houses and
>out of the gutters. They are waterproof obviously, but I didn't know much
>else about them and didn't want to spend $26.00 to learn that they wouldn't
>be usable (my insulation sucks, so the heat from my house melts my snow and
>ice- no use for them their.)
What is the wattage, and how long is the cable? For instance, if you
want a 25 watt 24 volt system, you need a cable that is rated at
approximately 500 watts at 110 volts. Ideally, it should be about 20
feet long if it is to work in your 55 gallon tank.