Transformer Secondary Protection?

[Bigjabe]

Hello,

I have a situation where it's 13.8kV pole-mount transformers protected at 125% by fuse cutouts, then conductors down to a panelboard mounted to the pole. The inspector is saying we need a main breaker on the panel. The transformers are 3 x 100kVA (289A FLA) protected by 15A fuses (which is 345A secondary current) and the panelboard is 400A.

Do I really need a main breaker on the panel?

 

[texie]

Under the NEC you sure do for a number of reasons. I'm sure the CEC is similar. Is this a service? That adds other issues.

 

[Bigjabe]

Under the NEC you sure do for a number of reasons. I'm sure the CEC is similar. Is this a service? That adds other issues.

No, it's just a tap off a private 13.8kV line at an industrial site. Other than simple convenience of disconnecting without operating the fuse cutouts, what are the reasons/code clauses?

Edit: sorry I didn't mention that the secondary voltage is 600V

 

[bwat]

My question is (probably incorrectly) assuming similarities between NEC and CEC, but how many breakers are in the panelboard and what are their ratings? In NEC I believe there could be some ways where you don't need a main breaker. (supervised and industrial locations..)

 

[mbrooke]

Those 125% fuses just START at 200-240% of their rating. Yes you need secondary protection, no doubt about it.

 

[don_resqcapt19]

My question is (probably incorrectly) assuming similarities between NEC and CEC, but how many breakers are in the panelboard and what are their ratings? In NEC I believe there could be some ways where you don't need a main breaker. (supervised and industrial locations..)

There are no "supervises and industrial locations" exception to the rule in 408.36 that requires a panelboard to be protected by a single main.

 

[bwat]

There are no "supervises and industrial locations" exception to the rule in 408.36 that requires a panelboard to be protected by a single main.

Valid point. The transformer protection and secondary conductor protection may have some exceptions like this that allow the lack of a main on the panelboard, but harder to get there when considering the protection of the panelboard requirement. 408.36 lists 240.21(C)(1) as a possibility for protection via the primary, but I don’t think that applies here. So it might actually be a panelboard protection requirement that drives the actual need here. Could all be moot anyway (NEC vs CEC).