How big a temp. swing should there be on my Ideal 55 pepsi machine?

[skbrothers]

Got my Ideal 55 Pepsi machine down to my basement and I'm ready to stock with beer/soda now...yea!!!

but......

When I run it, I notice that the thermostat won't kick the compressor on until the temp gets close to 50 degrees.  Then it runs until the temperature hits 30 degrees (maybe a bit lower even).

Overall that's about a 20 degree swing which seems a bit excessive.

I looked for an adjustment screw on the thermostat control, but find no screws/controls anywhere on it (except the actual temp control with Defrost, 1-2-3-4-5 settings)

I've sealed the sensor back up inside the liner of my machine so I don't believe ambient room air is interfering with the sensor.

It looks to be the original thermostat and not a replacement...could it be simply wearing out?

The unit only cycles every 15-20minutes so I think seal/insulation wise, I'm in decent shape.

What are the dangers of my soda/beer freezing if it's at 30degrees (or a bit less) every 15-20minutes.  Although the median temp seems to be around 40degrees, I doubt that my soda/beer would ever freeze, but certainly don't want to risk it.

Any thoughts/suggestions gang?

Thanks

Steve

[sliderchris]

Steve,
The thermostats that I use on my sliders are what are known as " defrost thermostats".
This means that they have a "cut-in" point (compressor turns on-non adjustable) at a temp. well above freezing ( in my case it's 41 deg.)
This allows the evaporator coils to shed any ice in-between cycles. The cut-out point (when the compressor shuts off)
is adjustable be moving the knob.The temp range is 23.5 to 31 deg.This means there is approx. 14 degrees
swing at a nominal setting (ie #4 on the knob).
If your t-stat is coming on at 50 deg. it may be time for a replacement.( available from some of this sites sponsors).
The small adjusting screws are mainly for altitude adjustment. I've messed with these before and found it's
very easy to lose track of where you started- I leave them alone now.
How are you measuring your temperatures? I have a beer bottle filled with water that I place a thermometer
in (that has a long probe.) This is placed roughly in the middle of the tank. This gives me a true "product"
temp, (we don't care too much about the liner temp.-it's the beer we worry about). I aim for 37-39 degrees.
I've never found any frozen beers even when I run the machine in the 32-36 range.
Chris. 

[skbrothers]

Hey Chris,

Thanks for the detailed reply!

Can't believe I didn't think to take a measurement from a bottle filled with water inside the cooler.  Great idea and absolutely the best measurement, as liquid in a bottle will vary much less than air temperature inside a box.

I made a project out of it yesterday with my 13 year old son.

We built a spread sheet and every half hour measured the cooler temp against the liquid in a bottle temp. All of which looks pretty cool on a chart. 
We took measurements starting at 11am and continuing through 11pm.

The cooler temp varied wildly, as much as a 17 degree swing from read to read.

The liquid in the bottle varied very little, holding an avg temp of 36 degrees.  High of 38 degrees and a low of 35 degrees.

I think I've got the cooler setting right where I want it now, but will continue to monitor it from time to time for the next several days/weeks.

Thanks again for the help Chris!

Steve