RV AC 521 compressor saver
Has anyone installed a 521 compressor saver on an AC unit? I know hard start 'boosters' are popular but, I haven't seen anything about the 5-2-1 compressor saver. They are usually installed on reside...
Forum Discussion
prichardson wrote:
5-2-1 and SUPCO are both hard start kits and consist of a potential relay and capacitor. Ideally the potential relay operating parameters should match the electrical properties of the compressor. Thus the best and safest hard start accessories to use are those available from the manufacturer of the A/C unit involved.
According to the tear-down/installation videos of the Supco, there was no relay - only PTC(s). So, it's operation is dependent upon how fast or slow they heat (and cool) with surge current. A 521 does use a potential relay which is directly dependent on motor back emf. I noticed on an installation video in a 13,500 RV ac, that both the PTC and 521 were shown on the units wiring diagram. So, if the manufacturers wiring diagram includes 521, then I think my question has been answered. That diagram also shows there is no relay in a PTC 2-wire circuit.
