Thermostat to control relay needed

[Tom Reed]

What I'm looking for and don't know where to start, except here, is a way to turn on a 120vac hydronic circ pump after the listeroid has warmed up. Ideally the controller would allow me to set a temp, say 80f and then turn on a relay when this set point was reached. The unit could run on 120vac from the generator and have a remote probe or thermocouple to sense the temp of the coolant line.

I'm trying to eliminate the 15-20 min run of cold water that now circulates through the hydronic system before the engine warms up.

So anyone know what this would called or where to start looking?

[potter]

A temperature snap switch may be the simplest .

[squarebob]

Part # 3F05-1

adjustable temp setting from 90 to 130. switch closes on temp rise.

http://s3.pexsupply.com/manuals/1249544603208/White-Rodgers-3F05.pdf

Bob

[BruceM]

I agree, the adjustable bimetal (snap) switch seems a good choice and is cheap.  McMaster.com carries them too.  They typically have a 15 degree F hysteresis (won't go off until at least 15F below the on temp). I use one on my cylinder head for an engine overheat sensor. Epoxy steel is a good thermal conductor, if you have an exposed fitting that's suitable for mounting the snap switch sensor. Silicone  caulk is a decent thermal conductor too.

[Tom Reed]

I bought this one http://www.senasys.com/shop/products-page/500-inch-radius-pipe-mount/2570f211/


It will clamp directly to the pipe and turns on at 80f and off at 65f.

[veggie]

Tom,

Nice find !
I did not know they existed.
I had been using the adjustable snap switch as squarebob suggested above, but they need a flat surface to mount on.


veggie

[BruceM]

Thanks for the tip, Tom.  That's a nice simple solution for coolant hose temperature sensing.

[rcavictim]

Over the years I have tossed a number of thermal disc snap switches and also the adjustable ones from electric hot water heaters in a parts bin.  I really must get some low oil pressure and overheat auto shutdown implemented on my gensets.

[bobansen]

I bought this one http://www.senasys.com/shop/products-page/500-inch-radius-pipe-mount/2570f211/


It will clamp directly to the pipe and turns on at 80f and off at 65f.

Hi Tom, is there any chance of you sending two of these units over here for me. we can not get such things in the Philippines. I can send cash bank to bank or money transfer which ever is best for you.
tks Bobbie
bobbietowers@yahoo.co.uk

[potter]

If you have no luck getting them try looking in old cloths driers or old electric hot water heaters, they are flat but  I have found that they work fine if strapped on tight.


   Potter

[Tom Reed]

Got mine yesterday and installed it right away. It is now wired in series with the circ pump and works just fine. The clip is size just right for a 3/4" pipe, but was a bit small for the 1" pipe used in the coolant loop. I just bent the clip to fit.

Bob, did you try to purchase from their sight? I think they take PayPal, so that should resolve the currency issues. If that does not work let me know and maybe we can put together an order.

These devices would also be handy to control a cooling fan on a radiator too.