We are in the process of trying to find out why 1/0 AL wire over 400' of length to supply a 2HP motor for a Bifold Door is being pushed so hard by door manufacturer.
We have a door on order with a 2HP motor, rated at 230-208 volts with approximately 10 FLA @ 230 volts. The spec'd OCPD is 30 amp.
To supply this motor, we have a long run of 400' from the meter with 240 volts supply (242 measured).
In an extreme situation of minimum wire size (10 AWG) with triple the inrush current of FLA (30 amps) we would get a voltage drop of approximately 10% down to 216 volts which is apparently within the nameplate rating of the motor.
Why is large voltage drop a problem if the operating voltage is within nameplate rating on motor?
If the name plate says "230-208 volts", why would 216 volts be a problem?
We are aware of many solutions all involving a varying amount of cost and effort (larger wire, buck-boost transformer, etc) but we do not understand the root of the issue.
We have been warned of damaging the motor in short order if we deviate from the recommendation of 1/0 AL wire in any way but the recommended wire size would only have a 1.5% voltage drop @ 30 amps. We are trying to understand why the recommendation. Is it more than a voltage issue?