Okay, here is a useful trick for you guys with clamp-on amp meters. If they don't have a low amp range of say 10 amps or so they are pretty much useless for measuring current of fractional hp motors. A lot of these digital clamp-ons have specs like +- 3% FS on a 100 amp range. That 3% of FULL SCALE. So trying to measure a motor that is supposed to draw 10 amps you could read anywhere from 7 amps to 13 amps!
Had this happen at a jobsite a little while ago on a 1 hp 3 phase 480 volt pump that was tripping out. The electrician says he amped it out and it is only pulling 1.2 amps, no problem it's rated 1.3 amps. I didn't believe his meter. I had him wind a ten turn coil of wire with the motor current running through it. Then put the ten turns in the clamp-on. He reads 23 amps now, and divides the reading by 10, to get 2.3 amps. Ahha! the motor is seriously overloaded!
I install these ten turn coils between the contactor and the overload block on all motors that draw less than about 10 amps. I always demonstrate the error to people, and they are always amazed at the magnitude of the error.
In the days of mercury thermostats with 'heat anticipators' I used to carry a 100 turn coild made of bell wire. I'd insert it in the thermostat circuit so my 6 amp clamp-on would read down to 60 milliamps.