Start circuit types for 110V AC fridge compressor

[phorvati]

I have a PTC thermistor type starting circuit with start capacitor on my newly purchased and installed 1/2HP 110V fridge compressor.
Prior to this i had a relay type starting circuit on a 1/3HP 110V AC compressor.

Things are working great but I am still trying to fully understand implications of PTC thermistor vs. relay type starting circuits.
The other day for instance I went to replace the raw water strainer as it was getting clogged, and I shut the fridge on the main AC breaker. After trying to restart the fridge, it did not start. I suppose PTC did not cool off enough in few minutes it took me to cleaner the strainer.

Thermostat was still calling for cooling but fridge compressor could not start.

After a while it started working. My circuit, or at least the way i wired it is shown below. My compressor did not come with installation instructions and I cannot find anything on it. It is QE QCF12-A.

So with PTC start, high current flows through start cap and PTC to get the compressor going, then PTC goes into high resistance. and run circuit remains. My question is, does PTC remain open for the remainder of compressor runtime? or is it supposed to go back to low resistance some time after compressor is running.
If i want to toss the PTC, can i use the relay type start circuit and its cap from my copeland compressor?

[transmitterdan]

Most control circuits have a time delay so they don’t try to start immediately when power is applied. This feature is not done by the PTC motor inrush limiter. But they work together. The timer makes sure that after a brief power loss the compressor does not attempt restart yet. By waiting the PTC has time to cool (and the back pressure bleeds off) thus the motor startup is much easier. Without this feature the motor might never start after a momentary power failure.