Understanding what size wire for 100 amps requires examining multiple perspectives and considerations. what size wire for a 100 amp subpanel 200' away.... The sub panel is 100 amp but what is the calculated load. If you are looking for the wire size for 100 amps at 240 then 2/0 alum. For copper you need #1.
For the EGC then look at T. 250.122 "If the doors of perception were cleansed everything would appear to man as it is, Infinite. 100 Amp Sub panel wire size - Electrician Talk.
The wire will be ran using single conductor Aluminum in EMT. Looking into 8-104 it says that if it is continuous the wire selected from table 3 is only good for 70% Meaning i would have to run a 3/0 based on the 75 deg column which seems crazy to me. Am i missing something here or is this the correct size for running this sub panel?
Similarly, 100 amp sub panel with #2 aluminum? The 90 amp Commander is about $250 whereas a 100 amp Commander breaker will run be about $100. I would have to run #1 aluminum to use the 100 amp commander though as opposed to #2 for 90.
I am just having a hard time finding 3/1 aluminum NMD90 at the suppliers and 3/3 copper is going to cost too much due to the length of run, about 80ft. 60 Amp EV Charger - Electrician Talk. With a 60 amp hardwired circuit, you could only use a charger that draws 48 amp. That is the most standard charger size.
As far as wire size, the NEC prohibits installing a 48 amp charger on a 60 amp circuit using #6 romex. #6 romex can handle 55 amp, and normally you could step up to the next available breaker size of 60 amp. 45 kVA transformer - Electrician Talk. A transformer can be oversized for the loads as long as the overload protection and conductor sizes match.
What is the size of the existing secondary main breaker? If two paralleled mains, the breaker amperages must be added together. If the secondary main is only 100 amps, you're only using 36 kVA of the transformer. 300ft, 200amp feeder run. Furthermore, what size wire would you run.
300ft from disconnect to panel. My calculations show 350 mcm Al for 3.46% vd. The client has a buddy that is a master electrician and is telling him to run 250/250/(4/0).
I'm suggesting 350/350/350 as it's a long run and I don't think derating the nuteral is worth the few bucks of cost...
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