neutral bonding jumper

[rootanp]

what is the minimum size for a bonding jumper from the secondary side of a Y transformer to 4-wire 480V switchgear - conductors are rated for 2500A? The loads are all three phase balanced. Also, should the size of the jumper from the transformer secondard neutral to ground be the same size as the jumper to the switchgear?

 

[DanDel]

Where is your location? The NEC 250.28(D) specifies this jumper(if I read your post correctly), but I believe it only applies to the USA.

 

[jbartos]

Suggestion: If conductors are rated and protected by 2500A overcurrent protective device, then the minimum size of equipment grounding conductors for grounding raceways and equipment would be 350kcmil copper; see NFPA 70-1996 Table 250-95, or visit

http://www.nfpa.org

for NFPA 70 National Electrical Code.