allowable Voltage drop

[asaeidi]

Is it acceptable according to NEC that during motor starting, which
the voltage of motor terminals may be decreased about 15%, the voltage
of other consumers which are connected to the same busbar decreases
more than 5%?
My case is raised in design of water fire fighting system electrical
network. The question is specifically regarding starting water reservoir
filling pump and its effects on operating voltage of other equipment
(pressure maintenance pump -jockey pump, lighting system, diesel pump
controller,...) which are connected to the same busbar. Is it allowable that
the above equipment having upto 15% voltage drop during filling pump
starting?
Look forward for your valuable answer.

 

[Dennis Alwon]

Is it acceptable according to NEC that during motor starting, which
the voltage of motor terminals may be decreased about 15%, the voltage
of other consumers which are connected to the same busbar decreases
more than 5%?
My case is raised in design of water fire fighting system electrical
network. The question is specifically regarding starting water reservoir
filling pump and its effects on operating voltage of other equipment
(pressure maintenance pump -jockey pump, lighting system, diesel pump
controller,...) which are connected to the same busbar. Is it allowable that
the above equipment having upto 15% voltage drop during filling pump
starting?
Look forward for your valuable answer.

I am guessing that art. 695.3 -- first sentence may be helpful but also read art. 695.7 Voltage Drop-- I think that is what you want.

The 5% decrease for other loads is not an NEC issue.-- art 210.19(A)(1) FPN #4 is not enforceable by the nec. It is a recommendation.