dana1028
Senior Member
- Location
- San Francisco Bay area
Just rec'd Mike's email - June NEC Questions - 2005.
Q3: Is a question about a 480:120/208 3-phase XO...if the primary has 125% protection [450.3(B)]...what is the maximum secondary conductor length?
A. The primary protection of an XO does not provide secondary conductor protection for a 4-wire secondary.....
OK - I'm not an XO geek. I've always protected primary and secondary conductors. I didn't see anything in the NEC about this (secondary conductors not being protected in a 4-wire system). Is there something in the NEC about this? Or is this something you're supposed to have learned during your journeyman training?
Q3: Is a question about a 480:120/208 3-phase XO...if the primary has 125% protection [450.3(B)]...what is the maximum secondary conductor length?
A. The primary protection of an XO does not provide secondary conductor protection for a 4-wire secondary.....
OK - I'm not an XO geek. I've always protected primary and secondary conductors. I didn't see anything in the NEC about this (secondary conductors not being protected in a 4-wire system). Is there something in the NEC about this? Or is this something you're supposed to have learned during your journeyman training?
