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Joined: Dec 2002
Posts: 308
E
Edward Offline OP
Member
I am installing a Buck&Boost transformer. Do i need to have a secondary OCPD.I tried to find it in the 1999 handbook(nec) no luck.

When does an installation require secondary protection?

Merci
Edward.


Thanks
Edward
2017 / 2014 NEC & Related Books and Study Guides
Joined: Aug 2003
Posts: 1,374
R
Moderator
You will probably only have to supply overcurrent protection on the primary side. 450.6(A) and (B) discuss a couple of instances in which secondary OCPD's are required. [Linked Image]


Ryan Jackson,
Salt Lake City
Joined: Jan 2003
Posts: 4,391
I
Moderator
Buck Boosts are autotransformer's and are only required to have primary protection.

450-4(a) 1999 or 2002


Bob Badger
Construction & Maintenance Electrician
Massachusetts
Joined: Apr 2002
Posts: 2,527
B
Moderator
They're covered in 99NEC 450-4(a) Autotransformers… Secondary overcurrent protection is generally not required, but also note when “secondary” [shunt] OCP is prohibited.




[This message has been edited by Bjarney (edited 02-09-2004).]


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