I was a member of HVAC Talk for several years. About 10 years ago. I used to post on here regularly. I'm a Fridgie, that SHOULD have retired by now, but still manage to bust knuckles, and frostbite fingers.

I was doing an Air Balance on Senior's lodge, Rather small, might I add. And during the testing of air flows, and such, I discovered that I was shy on Exhaust air. So the S&P fan houses a simple 1/2 hp motor that has a 7.9 amp rating FLA on the name plate. In order to 'tweek' a few extra CFM to bring the system into balance, I got the CFM I wanted simply by closing up the drive pulley one turn. However, I'm not drawing 8.4 amps... and the service factor on the name plate is 1.25.

What I've learned over the years, that an electric motor 1 phase, has a 'buffer' built into it (SF), that allows for the odd power spike, an unexpected load, or other situations that cause it to draw a little more than rated amperage. It's not really meant (at all) for constant service well into the SF of the motor's normal rating.

I'm only FAIR at math, and .5amps above my rated 7.9 amps... does this mean I'm searching for a higher HP motor to maintain the now perfect airflow I've achieved?

If I were to leave this motor chugging along at a 1/2 amp higher than rated, but still with in SF... Am I likely to see myself administering a service call in the near future?

Ric