Panelboard supplied through transformer- OCPD.

[housemoney]

Would appreciate a quick simple sanity check here: I have a 3 phase MLO 208/120 30 circuit panelboard fed from a 3 phase transformer as shown below.

Per NEC 408.36 (B) this panelboard requires secondary side overcurrent protection-MCB, fusible disconnect etc.. (not MLO straight off the transformer)?

The exception: 240.21 C/1 would not apply

 

[d0nut]

Correct. See also 240.21(C).

 

[jim dungar]

Many decades ago this was a common installation method. Changes to the NEC made it non-compliant for new installations.

But, many designers continue to do what they have always done.

 

[augie47]

You are correct.. 408.36

 

[jim dungar]

You are correct.. 408.36

As well as the 'tap rules' for transformer secondary conductors in 240.21(C).

 

[infinity]

I agree, the installation that is depicted is not code compliant.