Short Cycling Problem

clint
New Member

Posts: 9

Short Cycling Problem Jan 28, 2016 3:29:47 GMT

Quote

Post by clint on Jan 28, 2016 3:29:47 GMT

Thanks for the information. I have replaced the relay with the Supco R081 and the short cycling issue seems to have stopped. When I first started the refrigerator it was still pulling around 250 watts but didn't trip the overload and it slowly backed down to 160 watts. Now it stays between 160 and 190 watts when running.

The new relay seems to be very hot after the refrigerator runs. I can only touch it for a second or two before I have to stop. Is this normal or a problem with the new relay?

When I was installing the new relay I ohmed the compressor and got the following readings
Common to Run 4 Ohms
Common to Start 19.6 Ohms
Run to Start 23.3 Ohms

ChrisJ
Administrator

Posts: 2,502

Short Cycling Problem Jan 28, 2016 4:04:12 GMT

Quote

Post by ChrisJ on Jan 28, 2016 4:04:12 GMT

Sounds normal.
That relay works on heat as it's not a mechanical relay. It also has a built in overload.

Here are the specs I received in an email from Supco.

The overload protector in a URO81 has a steady state RLA [run load amps]
of 4 amps.
This means that the UTC [ultimate trip current] is 4 amps. If the
continuous draw amps exceeds 4 amps the URO81 will trip in about 15
seconds at a 70 degrees.
The LRA [locked rotor amps] protection is 12 amps, this will trip in
about 2 seconds. The URO81 is a PTC device and runs hot to the touch as
all PTC relays do.

I think URO81 has terminals, RO81 has wires.

Last Edit: Jan 28, 2016 4:04:51 GMT by ChrisJ

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coldspaces 27 Cubic Foot Posts: 3,091	Short Cycling Problem Jan 28, 2016 6:07:55 GMT Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by coldspaces on Jan 28, 2016 6:07:55 GMT Great to hear that the relay seems to have solved the problem. Those ohm readings on the windings look pretty good if memory serves me.
	I don't own too much old stuff,I just temporarily take care of it for its next owner. "Hell, there are no rules here--we're trying to accomplish something!" Thomas A. Edison We never really grow up, we just learn how to act in public.

clint New Member Posts: 9	Short Cycling Problem Jan 28, 2016 12:17:46 GMT Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by clint on Jan 28, 2016 12:17:46 GMT Thanks for all the help and suggestions. I appreciate it.

Post by clint on Jan 28, 2016 3:29:47 GMT

Post by ChrisJ on Jan 28, 2016 4:04:12 GMT

Post by coldspaces on Jan 28, 2016 6:07:55 GMT

Post by clint on Jan 28, 2016 12:17:46 GMT