Starting Motor Voltage Drop

[Nurah]

is there any code where recomend allowable percentage voltage drop for sizing the motor conductor for different controller or starter when starting?

for example :
DOL allow 20% VD at 6 x Full load current.
What is allow for Reduce Voltage (soft starter) and VSD ?

 

[iwire]

Code wise only fire pumps have voltage drop limits during start up, they are limited to 15% voltage drop at locked rotor current.

Good design wise I do not know the answer.

 

[farmaped]

That is good design (15% max). More than that will create much trouble will other equipment falling off-line, and your neighbors may notice.
Should not be an issue with VSDs, just adjust your start accordingly.