Looking for a niche product. Maybe have to build one

[Hynek]

What I'm looking for is a simple AC contact switch that can open or close within a certain voltage range. Basically a load dump switch to power a heater to keep my lifepo4 batteries and micro hydro from freezing.

I have a Xantrex C40 charge controller that can load dump but I want to switch on and off more than one AC heater and heat trace. The C40 is just to inaccurate for my liking as well. And of course the tendency would be the controller to keep my batteries at the top of the charge continuously throughout the winter. Something I'd like to avoid

Does anyone know where one can find this sort of thing? I don't even know how to phrase it for a google search.

Thanks in advance!

 

[FilterGuy]

I am not aware of such a beast....There are voltage controlled relays and there are power relays/contactors.... but I don't know of any voltage controlled power relays.

Having said that, it should be reasonably straight forward to use a low powered voltage controlled relay to activate a power relay.

Start with a search for Voltage controlled relay or voltage monitoring relay. I think you are wanting to watch the battery voltage so this might do the trick: https://www.amazon.com/Voltage-Monitoring-Over-Voltage-Under-Voltage-Protection/dp/B07QJ8B21R/


However its contacts are probably not sufficient for switching the heater load so you probably want to have it drive a power relay/ Contactor.

 

[Warpspeed]

What is wrong with using an off the shelf normal programmable temperature controller ?
Plenty of variety on flea-bay:
https://www.ebay.com.au/sch/i.html?...=programmable+temperature+controller&_sacat=0

 

[DIYrich]

Something like a 53.5v zener diode controlling a relay that controls an SCR to turn on power to heater.