Authority specifying use of interlocking keys1

[wyreman]

We have new 12kv buildings added to our distribution and the install is signed off. Now we go to the AB xfmr loop selector and find there is kirk key there but no "mates" to the interlock. I would think the interlock would be:

==> distribution should open before a/b can be switched
==> primary could/should be open before a/b can be switched altho it is suppose to be rated to be switched under load, I don't want to do it.
==> finally a/b pentagon bolt can be accessed.

Aside from kirk, and the EE, who is the actually code reference/authority showing the rules.

thanks

 

[rbalex]

...
Aside from kirk, and the EE, who is the actually code reference/authority showing the rules...

Absent knowing the details of your "campus," the closest NEC reference would be 225.30(E). Key interlocks are not generally an NEC requirement for this particular application type; they may be for certain "lock-out" applications. If your AHJ is requesting it, ask for a reference.

 

[weressl]

We have new 12kv buildings added to our distribution and the install is signed off. Now we go to the AB xfmr loop selector and find there is kirk key there but no "mates" to the interlock. I would think the interlock would be:

==> distribution should open before a/b can be switched
==> primary could/should be open before a/b can be switched altho it is suppose to be rated to be switched under load, I don't want to do it.
==> finally a/b pentagon bolt can be accessed.

Aside from kirk, and the EE, who is the actually code reference/authority showing the rules.

thanks

The selector switch is most likely to be a no-load-break switch and a corresponding interlock cylinder should be installed on the main secondary, captive in the ON position of the breaker.

It may be automatically provided by the manufacturer if it is sold as the close coupled primary selector on the transformer. Either you are missing some information on how and what was ordered, and/or there are some other components shipped loose with the transformer.

 

[wyreman]

Schematic?

Schematic?

How can I draw a schematic. I can draw switch itself. But how would I represent 4 position sectionalizing $ on a map?