Dennis wrote:

I picked up a small fridge compressor with the idea of playing around
using it for a vacuum pick up tool for small electronics parts, but it
behaves strangely.

On initial power up it runs fine, very quietly.

It quickly/easily pulls down to 20kpa (-80kPa).


However if I disconnect the power and reconnect there is a quiet hum like
the motor is stalled (motor is not running & there is no airflow).
These things have thermal starting controls that take a couple minutes
to reset properly before re-starting. So, either leave it running as long
as you need it, or get a different starting control such as a "sinpac
switch" which is electronic, or a potential relay type.

Jon