Neutral Sizing For EV Charger

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
Would someone mind checking me, I don't normally resize the grounded conductor, but I was asked to save some pennies.

I have EV chargers using 480V 3Ph requiring 4-wire plus ground. The largest one is 180kW with an input current of 240A and 300A MOCP. I'm using 350mcm for the phase conductors, and if I use table 250.122 per 215.2(A)(2), I could use a #4 for the grounded (neutral) and EGC. Does that sound correct?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Yes #4 is the smallest the neutral can be however what is the calculated load for the neutral? If it is just for some electronics then 4 copper is fine
 

Rock86

Senior Member
Location
new york
Occupation
Electrical Engineer / Electrician
Yes #4 is the smallest the neutral can be however what is the calculated load for the neutral? If it is just for some electronics then 4 copper is fine
Looking at the cut sheet (no wiring diagrams / schematics) looks like aside from the control panel there are some safety features such as a 20mA GFCI, but no real load major load on the neutral which I can see.
 
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