Transformer secondary protection

[Jeff@BTE]

When protecting the secondary output for a 120/208v 3 phase Y transformer, is there a maximum length of unprotected wire before going from the output of the transformer to the main breaker of the electrical panel or fused disconnect?

 

[augie47]

The maximum length is unlimited IF you meet the requirements of 240.21(C)(4) {2017} but the length can be limited depending on which of the 240.21(C) tap rules is applicable + other rules in 240 Part VIII for supervised industrial applications.,

 

[Johnhall30]

10 feet

240.21 (C) (2)

 

[infinity]

25' may also apply.