Both my new mill and lathe take 100 amp main fuses. I got 100 amp safety switches and need to wire from the switch to the machine. I'll be putting all the wire in 2" metal conduit. Four conductors per machine - 8 total.
Ugly's Electrical Reference has the ampacity of more than 3 conductors on page 67. It show #3 THHN has an ampacity of 110 amps. Is this the correct wire size to get?
Does the nuetral have to be as large by the electrical code?
Karl
Karl
100 amp to a mill or lathe sounds like 25HP or bigger. But before you get a straight answer you need to let us know how many HP and what voltage. Three phase is assumed but verify this. And is you power panel capable of 2 each 3 phase 100 amp circuits? And a neutral. Not usually wwith a setup like this unless there is a 115 volt lighting or receptavle included. More information please. Bob AZ
I think that would be OK. #2 THHN => 130A x .70 = 91A
If you meet all the required conditions, you're allowed to use the next higher standard rating overcurrent device to protect the conductors. I assume that would be 100A.
Ned Simmons
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