Johnson A419 Controller Manual & Question

[Pete]

I found this yesterday on Johnson's site: Johnson A419 Manual

I think I'll set my controller up in the following way once it comes:
-Cooling (no JUMP1 Jumper)
-At Cut-Out (JUMP2 Jumper Installed)
-Setpoint: 64*F
-Differential: 2*F

With these controls, the fridge should kick on at 66*F and off at 64*F.
Does that sound about right?

[jerseynewbie]

Originally Posted by Pete

I found this yesterday on Johnson's site: Johnson A419 Manual

I think I'll set my controller up in the following way once it comes:
-Cooling (no JUMP1 Jumper)
-At Cut-Out (JUMP2 Jumper Installed)
-Setpoint: 64*F
-Differential: 2*F

With these controls, the fridge should kick on at 66*F and off at 64*F.
Does that sound about right?

Just be careful with sensor placement. I installed mine yesterday, and it wouldn't fit through the condensation drain area on the Edgestar (plus I don't want to block that hole just in case I get any condensation). Don't worry about putting the sensor in through the door seal, I tried it. The wire is thick enough that it allows way too much air to escape through the seal, so it's not an option. I ended up drilling through the back of the case (below the cooling assembly that that I wouldn't damage andything), the insulation, and the interior lining. You'll need a bit the same size as the sensor, and at least 3 inches long.

Sidebar: You can mount the A419 on the back of the wine cooler, in the recess below the cooling unit, and then hide all the extra wires up in the shroud around the cooling unit. This enables you to slide the cooler all the way back to the wall (sill allow a couple inches for air circulation), and keeps the wires from ever getting caught on something and being pulled out of the A419 or the wine cooler. Plus it looks much more professional.

I then mounted the sensor on the back wall, about halfway up, and sealed the minimal airspace around the wire. Unfortunately, this is pretty close to the cooling unit, therefore it can read that it's already chilled to 64 when the air just hasn't had enough time to circulate. Then, the cooling unit cuts out, as it's designed to do, the air circulates with the oust fans, and a few minutes later when the temp has equalized, the sensor reads that it's too warm and cycles again.

One way to get around this is to set the minimum time between cycles. I believe it can be anwhere from 1-30 minutes, but don't quote me on that. Right now I have the differential down to one degree, and the cycle set for 5 minute minimum. But if you're going to take this route, with the sensor near the cooling unit and a minimum cycle time set, you'll need to bump the A419 setpoint down a couple of degrees.

Another option is just to run the sensor around to the top, bottom, or sides, and tape the excess wire against the lining so it doesn't get snagged on your shelves. Just be aware that if the sensor is on the top or the bottom, the temp might be significantly different than elsewhere in the cooler. In theory, the air circulation should be good enough to make this a non-issue, but it really depends on how packed your cooler is.

Don't look at the temp on the unit itself, monitor the temp with a digital thermo/hygro that you know is calibrated. Wireless is best, unless your door is transparent enough to see the reading. That way you don't have to open the door so much while you're tweaking the initial setup. Plus if you have two wireless sensors, one on the top and one on the bottom, you can monitor the efficiency of your air circulation system.

After a few more days of playing around with it I'll be able to tell you more.