Test Terminal Block/Test Switches in MV Switchgear

The preference would be to mount the test switches and terminals on the door external to the inside of the MV cabinet.

This way the cabinet door provides a barrier to the MV internal to the cabinet and reduces arc flash consequences should something internal fail during the access and testing. It also prevents inadvertent contact with live metal contacts within the cabinet.

Remember one flash and you're ash!

On the door of the LV cubicle would be a typical location for MV switchgear in the past.

On the door of the MV cubicle would require additional engineering evaluation of the door strength under various fault conditions, where the door strength would be affected by equipment cutouts and/or flammable components.