15HP motor on panel

[la2151]

HI.. am looking for others thoughts on putting that large of a air compressor motor on a existing panel that is all used for general office lights & plugs? I don't like the idea & my electrical engineer recommends I not do it.. The GC keeps asking why not too dsnt totally believe me..
Thanks for input guys.

 

[chris kennedy]

Got more info like 1? or 3, feeder wire size to the existing panel and existing load?

 

[Cow]

Is it on a VFD or soft start?

 

[LarryFine]

What's the panel and feeder rating and the present load?

 

[la2151]

motor on panel.

motor on panel.

sorry wasn't thinking. gave a really broad description. It is a 120/208 3 ph 200 amp panel. the existing load is only 90 amps. the new 15hp motor is 208 3 ph as well. I am more worried about lights dimming every time the air compressor comes on. MY electrical engineer calctd it as ok but he expressed a concern on motor starting.. It is just the GC that is saying are you sure??? GC can be stubborn. what are others thoughts. I think the feeders to panel are at least 3/0.. have to ck on monday
thanks

 

[mcclary's electrical]

Based on what you say,I would install it

 

[kwired]

use a soft start control if there is problems with lights dimming,

may also add to life of motor and compressor.

 

[ElecEngCons]

Well its important to determine what size the breaker is feeding this panel. 3/0 conductors are good for 200 amps so I am assuming that the breaker is sized for 200A. If this is the case then it shouldnt be an issue, 15hp motors at 208V 3ph account for 46.2 FLA. Breakers for motors are typically sized for 1.75 of the FLA to account for initial startup. 90A + 46.2A X 1.75 = 170.85A so you should be ok.