-
Turbo Air JRF-19
I have a Turbo Air JRF-19 dual chamber unit. Building took an electrical hit. Burn out main board on unit. Visually it was burnt. Ordered direct replacement. Installed wire per wire, not to mix any up. But I don’t think you can. Unit fired up, pulled temp to set points. Thought I was done. Get a photo few days later of the outlet melted down. Returned to find, after having to contact Turbo Air support… The neutral to the compressor and fan drop out, but not the 115v. So the compressor and condenser fan begin to overheat. Turbo Air tech support said the board should not do this, but have no answers on fixing. I’ve been through two NEW boards, same result. I can’t just throw on some standard controls due to the dual chamber setup. Any help is much appreciated.
-
21 Replies
-
Sounds like you have a compressor problem. Test the winding’s and the start capacitor. Also test the defrost heater circuit for a short. If it was from a lightening strike, You may want to obtain a Megger and check all the curcuits for a leak to ground. Especially the defrost. Chased my tail before on one like this.
-
Amp draw meets nameplate.
I remove plug from main board to compressor, I tested the output on board, still reading 120v on compressor output on board.
-
You should only have power to the compressor during a call for cooling. How are you measuring it, Not to ground, only to the black common like in the wiring diagram.
-
-
-
You can find the wiring diagram in this manual.
-
I printed that out. Doesn’t say much, and there is more that can be done via interface that they don’t have in manual.
-
Turbo Air had me “change board programs” via interface, they as had me force a defrost, and thats where we found 120v on the compressor output during defrost and once unit satisfied.
-
-
I forgot all about the stepping motor to feed either the freezer or cooler. Check your running amps of the compressor to make sure both are not open at the same time and making a overload condition.
-
During cycle on time, everything looks and measures darn near perfect. It’s during the off cycle, or defrost.
-
-
Ok, can you post a picture of the burned board. It will tell us what shorted. Also if you look at the board, The wire connections are labeled for the compressor and the defrost heat system. You can follow them back on the traces of the board to determine the high current. ie. what’s smoked.
Embarco compressors are not the best for low temp longivity. Especially a 1 hp. So make sure to ohm the windings and replace the starter. I’m not a fan of the PCT’s.
-
Andy, make sure to inspect the spade connectors that connect to the board to be bright and tight. If the wires or connectors have suffered high heat they will ruin a new board from resistance heating.
-
There should not be power to the compressor during defrost.
You can only check the compressor at the compressor. You have to pull off the protection cover and the PTC starter to test the compressor winding’s. You ohm the common to start, common to run, and common to ground/chassis. And the sum of start-common and run common should equal start-run. Any terminal to the chassis should be infinity. I don’t off the top of my head know the proper values of the winding’s for that model Embarco, but it shouldn’t be hard to find on line.
-
Compressor power should be between the yellow and black wires of the main board comm 1. Defrost is the gray and black. But that also supplys the drain heaters.
But be careful, sometimes Turbo Air does not document all there changes and additions.
-
-
I looked up the motor spec’s. Start winding is 30.4 ohm. Run winding is 4.2 ohm.
-
You’re missed some info…. condenser fan does the same exact thing. So a failed compressor AND condenser fan motor?? …. maybe… But if windings are failing, it wouldn’t manifest during off cycle. No?
When measuring at the board, connector unplugged, 120v to ground, measured per Turbo Air….
No spade connections, pin… if was lose, Id see a hot spot there, not the case. All clean.
Old board is long gone. This issue has been over a month.
-
I’ll have to go and check that today if I get time.
-
-
One should never test to Ground except for leakage. To test for power to a motor or other load you would test to nuetral. Not Ground. There are circuits out there that sometimes are in series and can lose neutral.
And if a building supply system loses nuetral. Your 115V can become 230V
-
I think this is the answer. Bet they are trying to cycle off neutral, compressor is compromised. “leaking” to ground. That’s actually the best direction here.
-
-
If you had a nuetral lost, It would cook the low voltage transformer for the board.
-
power supply board is separate. the circuit off the main board to compressor is dropping neutral. And then taking your theory, which I think is right, the compressor is shorting to ground.
-
The compressor has a isolated electrical system to prevent a short to ground. If it ohms out to ground there is no choice but to replace it.
-
-
-
Wow. Going through fixbear’s posts I learned quite a bit in regards to testing compressors. Thanks for the data.
Good luck Andy with the “hunt”
Log in to reply.