what are the requirements for grounding bonding jumber for the enclosure door of a controlgear. i have 2 cases one with instruments mounted on the door and the other with no instruments mounted on the door except for indicating lamps.
It depends a lot on the enclosure environment, and how much hinge/grounding continuity is needed over panel life. Moisture or corrosives may dictate a flexible-jumper shunt across the door hinge(s). In some cases, regardless of panel location, a jumper {kit} is a default specification—with or without door-mounted components.
Irrespective of statutory requirements, if the equipment mounted on the cubicle door is powered by or used to switch AC voltage (eg push-buttons, selector switches, volts/amps meters, indicator lamps etc, etc) then from a 'safety' point of view it is good practice to earth any door.
In the US, hinges alone are generally permissible from a code/safety standpoint, but that should be considered the bare minimum. I believe some other contries may have additional requirements -- there was a relatively recent thread (within about the last 6 months) that discussed some of those requirements in other countries, let me know if you have trouble locating it.
Obviously, in any country, specific project requirements might dictate an installation which surpasses minimum code requirements. More substantial grounding (than relying on hinges alone) might be desireable where high-fault currents, EM radiation, or sensitive electronics are involved.
I was taught not to rely on the continuity of the door hinges because they may eventually corrode. So I always put a ground wire on a weldstud on the lower left inside corner if the door has any AC powered door-mounted items.