100 HP motor, RVAT starter rating exceeded

[markac]

We have a pumping application where it was indicated that 460V, 100 HP pump motors would be supplied. NEMA size 4, reduced voltage (autotransformer) starters were installed. The supply voltage will be 480V. Upon arrival, the pump motor nameplate indicates 135 FLA at 460V. The starter manufacturer initially remarked that the starter was rated for only 124A maximum. After reviewing, the manufacturer states that the contactor is rated for 135A, but the highest rated thermal unit will be 134A. At 480V, I believe the motors will operate at 129A.
Any suggestions on performance issues that we can expect if operating with the 134A thermal units? Any other comments, suggestions?

 

[jbartos]

Suggestion: Replace the starter for NEMA Size 5 since there is no design margin. Also, the motor is designed to draw more current than the rated current if the motor rated voltage on the motor nameplate drops 10%, which is within the NEMA design margin.

 

[busbar]

Weigh the consequences and costs of a nuisance trip. In many cases, the disparity might be considered, "close enough for government work."