Not sure if this the place for this , but I bet I get an answer....I had to do a start up for another contractor on an exhaust fan at a waste water treatment plant...I didn't do the install. Small fan, dont even know the HP, but it doesn't matter here. Here's the problem. Motor starter trips after about five minutes. (overloads they installed were too small)
Motor data as follows:
460v/3ph fla .55 service factor 1.0
The overloads installed were .32 to .35 amps. (Sq D BO.51...I think)
Actual amp draw .6/.7/.6 (each of the three legs).
My question is, if I put in bigger overloads on the starter to handle up to .7 or .8 amps, will I hurt the motor, or am I being too fussy? I know I would be over the service factor, and I'm not too comfortable about it.
Don't want to mess with the adjustable shieve just yet, the cfm here is really important here and the contractor doesn't want me to do that just yet. Everything is explosion proof and I guess the air exchanges are important.
What do you guys think?