How should two pieces of equipment be properly bonded?

The proper bonding of two pieces of equipment is achieved by connecting them with a bonding jumper of appropriate size to ensure electrical continuity. This method ensures that both pieces of equipment are at the same electrical potential, which significantly reduces the risk of electric shock and minimizes the possibility of arcing in the event of a fault.

A bonding jumper is a conductor specifically selected to carry fault current; its size is determined based on the equipment types and the potential fault conditions they may encounter. The use of a properly sized bonding jumper is crucial as it allows for the effective transfer of fault current, which can activate protective devices like circuit breakers or fuses, thereby enhancing overall safety in electrical systems.

Utilizing an insulator (as mentioned in another choice) would negate electrical continuity, which is essential for effective bonding. Welding would not provide the required electrical continuity needed for bonding and could cause structural and operational issues. Lastly, sharing an electrical source does not establish a direct electrical connection required for proper bonding between the two pieces of equipment.