[Jim Port]

The determining factor is whether the panel is listed for use with tandems. Can you post the model number?

 

[Jim Port]

Agree with Frank. No tandems allowed.

 

[Jim Port]

Single pole 60s are not made.

 

[Jim Port]

Single pole 50s aren't made either. You could move 2 circuits out of the panel to add a 2 pole to feed a subpanel.

 

[Jim Port]

A 2 pole takes 2 spaces. The OPS panel is good for 40 spaces and is already overfilled.

 

[Jim Port]

. There is no longer a reason to limit the number of breakers which can be installed to what the panel was originally listed for.

The NEC change removing the circuit limit is not retroactive.