Over amperage on cook return fan
Ive got a 1.5 hp 1750 rpm 460 volt return fan motor that has been giving me issues overamping for the last 2 months. The freq drive is tripping on calculated motor temp. Basically it monitors the motors amperage and bases that on motor temperature. The nameplate states that at 460 volt the motor should pull 2.2 amps. The motor is pulling 3 to 3.5 amps. I replaced it with a weg motor with the same nameplate data. New motor is doing the same thing. Ive checked all my connections, looked at the contacts on the contactor. Everything looks good. I even bypassed the drive itself by running temporary wires directly from the disconnect to the motor. Same problem. The fan spins freely, as free as the identical one located in the same mech room which is running normal at 1.8 amps. The belt is snug like it should be. Remove the belt and the motor pulls .8 amps. My voltage looks good at 492 across all three legs. Something has changed in the last 2 months that is now causing this problem. Any ideas?