Thanks All
The panel is 12" wide, 21" tall and 6" deep.
It's not the size of your knob it's how you use it
The panel is in a class 1 div 1 area for explosion resistance so it has a positive pressure system attached(Purge). There is a internal pressure switch so that when pressure is lost inside the panel a light and audible alarm go off. The audible is irritating so it can be silenced but only temporarily so you don't forget there is a faulty condition.
The make-up current limit is set so that when you screw the drill pipe into the top drive the motor only draws enough current equivalent to a torque value.