setting-up a Johnson A419 controller

[CButterworth]

My Johnson A419 digital controller will be arriving in a couple of days. I have my freezer ready and will use the controller to keep my kegs at around 54F.

So what are the best settings on the controller:

obviously 54F will be one of them, but set to shut-off?

What about the differential?

It also seems that opinions differ with regard to how to place the probe. Given the buffering of a large thermal mass (5 gallons of beer in a keg), I'd initially have gone with trying to keep air-temp at an average of 54F, but with a large differential (due to the slow changes in temp of the kegs).

However, many forum users report that attaching the probe to the side of the keg, covering it with a little insulation and tape (or even plumber's putty) works very well. I would expect the differential to be set to a much lower tolerance using this method.

Thirdly, using a thermo-well.

So, my options would be:

A. 54F set-point, 4F differential either side of the set-point, probe in the air.

B. 54F set-point, 1F differential either side of the set-point, probe taped and insulated to the keg.

C. 54F set-point, ? differential, probe in thermo-well (1 g water)? But are the Johnson probes really waterproof?

I know this may open a can-of-worms, but I'd appreciate any comments, from folk of have experienced these different methods.

Thanks,
Charlie

 

[whoaru99]

Unless you're changing kegs often I think the air temp would be fine as equilibrium is achieved. Not like your're trying to actively cool down, for lack of better terms, a rising fermentation temperature where immersion would be ideal.

 

[CButterworth]

I'll get a little more careful about the temps, when I use the keeper for fermenting. Luckily, during the winter months, I needn't worry as our basement utility room sits around 62F!

Charlie (does not surf)

 

[whoaru99]

Oh...hehehe...the signature line, "Charlie don't surf.", is a line from the movie Apocalypse Now.