Those with Johnson temp controllers... help?

Hey guys,

Starting a Keezer build - I have a freezer & my johnson temp controller but I am greatly confused on the instructions for the Johnson A419 (digital temp controller)

I'm really confused with the set point & differential instructions... jumpers etc etc...

Do I set the jumpers to cooling mode, Cut-in at setpoint or cooling mode, cut-out at set point? Or do I mess with the differential settings too?

I'd like to keep the freezer around 36, so I set it on SP (cooling mode cut-in at set point).... at 37 degrees freezer turned on and cooled past 36... kept going down to 32 before I just unplugged it.

How do you guys have the A419 set to keep the freezer from freezing and to kick on at 36?

Do I need to leave the set point at 36... & modify the DIF point also?

I'm trying to remember exactly how I did mine, let's see I would say you'd want to be wired in on the NO relay contacts, you want cut OUT at setpoint in cooling mode. Dif is how low it goes before cutting out. So I think if you set it for 37F setpoint, with 1 deg differential, it would then come on at 37F and cut off at 36F. Now that's what it is sensing at the probe at the time, so you might see an extra degree or two of drop even after it cuts off from the freezer.

Anti short cycle delay I like set to 10 minutes, but it should be at least 3 minutes to protect your compressor.

maybe that's where I am BUZZED in the head... is cut-in powered on and cut-out power off?

Or the other way... cut-in power off, cut-in power on...

o-0

I would say just try it both ways, just plug a lamp into it, then set it for a couple degrees above ambient (or whatever temp it is reading), set the short cycle to 0 for testing, then play around with it until you get it to come on above the setpoint, and turn off below the setpoint. Maybe use a small dish of warm and cool water so you can dip the tip of the probe into it to get it to change temperature fairly quickly for testing.

I didn't even think about testing it on a lamp with warm/cold water in glasses.

told you my mind was BUZZED today.... long week.

Awesome & thanks!