Ranco 2 stage temp controller?

[timr62]

I was looking at a Ranco 2 stage temp controller. This device is supposed to have the ability to handle two separate devices, heating and cooling. According to the description it is programable for separate temps and ranges. My question is how? It has only one temp. probe yet 2 separate outlets to plug into. Wouldn't both devices be kept at the same temp with only one probe? Wouldn't you need two probes as well? The salesman at the brew store couldn't explain it. I was hoping to use it to control a frige and a fermwrap on a carboy. The carboy would sit on the 58 degree basement floor. Anybody have experience with a 2 stage controller? Thanks in advance Tim

[Travisty]

Wouldn't both devices be kept at the same temp with only one probe?

Yup. The two stage controllers aren't meant to keep two seperate vessels at specified temps. They're designed to keep one vessel within a specified range whereas one stage controllers can only keep a vessel above or below a set temp. The way most of us use the two stage controllers is to put our fermentation vessels inside a fridge and plug the fridge into the cooling side of the controller and plug a heating device into the heating side. Then you can set how hot the fermentation can get and how cold it can get.

In order to keep a fridge at one temp and an outside carboy at another temp you will need a controller for each.

[timr62]

Ok, thanks. That makes sense. Is there a way to set up one of the with 2 probes? So that it would handle 2 fermwrap heaters? My basement is always too cool for most ales, even in summer. Trying to avoid buying a separate controller for each carboy.
Thanks, Tim

[bigdan]

It's not for two vessels it's for two stages one cool/ one heat, two cooling, or two heating. You could control two freezers I guess, but you would have to wire the sensors in series and they would only take an average, so you would be off a little on both. I think you can technically wire up to four sensors. I think this feature is still for controlling one vessel or area that's a bit bigger and you need to take more readings to get a better feel for the total ambient temp of that space.

[NMWildAles]

Yeah, one probe sends temp to controller. Controller determines whether you need cooling or heating. You set the temp band you want to maintain, if it is too hot your cooling device comes on, liklewise if it is too cold your heating device comes on. In my case it is a chest freezer for cooling and a portable heater for raising the temp.

[timr62]

Thanks for the help
Tim