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nestork nestork is offline
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Quote:
Originally Posted by Stormin Mormon[_10_] View Post
I remember from some where, refrigerator compressors have a LRA, or
Locked Rotor Amps rating. I think some motors do, also.
All electric motors do.

What is locked rotor current

According to the above web page, the Locked Rotor Amperage is the current draw during the instant the motor is first turned on and the rotor is effectively still stationary. It's essentially what you're thinking from it's name; the current that would flow through the stator if the rotor weren't turning.

That web page says the current through the motor when it's starting is anywhere from 3 to 8 times the current it draws when it's running under full load at normal speed. So, if you have an electric motor that draws 5 amps, it can draw anywhere from 15 to 40 amps when it's first starting.

I guess that's why appliances that draw a lot of amperage, like air conditioners and air compressors will often require "Slo Blo" fuses that allow for that high initial tarting current without blowing.