Exposed noncurrent-carrying metal parts of fixed equipment which may become energized shall be grounded under any of the following conditions:
If within 8 feet (2.44 m) vertically or 5 feet (1.52 m) horizontally of ground or grounded metal objects and subject to employee contact.
If located in a wet or damp location and subject to employee contact.
If in electrical contact with metal.
If in a hazardous (classified) location.
If supplied by a metal-clad, metal-sheathed, or grounded metal raceway wiring method.
If equipment operates with any terminal at over 150 volts to ground; however, the following need not be grounded:
Enclosures for switches or circuit breakers used for other than service equipment and accessible to qualified persons only;
Metal frames of electrically heated appliances which are permanently and effectively insulated from ground; and
The cases of distribution apparatus such as transformers and capacitors mounted on wooden poles at a height exceeding 8 feet (2.44 m) above ground or grade level.