What electrical connection should be made to a battery charger case/chassis?

The correct approach involves connecting the battery charger case or chassis to a grounding bus using a conductor that has the same ampacity as the DC positive conductor. This is critical for safety reasons. By utilizing a grounding connection that is appropriately sized, one ensures that any potential fault currents—whether due to a short circuit or equipment failure—are effectively channeled to ground. This helps prevent electrical shock hazards and the risk of fire from electrical faults.

In marine environments, where battery chargers are commonly used, proper grounding is even more crucial due to the additional risks posed by water, which can facilitate electrical pathways that increase the likelihood of short circuits. Ensuring that the grounding system can handle fault currents minimizes the chance of equipment malfunction and enhances overall safety onboard.

The other options do not provide the same level of safety or compliance with standards. For instance, only connecting to a negative battery terminal may not ensure that fault currents are managed effectively. A small gauge wire to ground indefinitely lacks the capacity to safeguard against higher current loads, and not making any connection at all could leave the system vulnerable to faults, thereby increasing the risk of serious incidents. Thus, the proper connection to a grounding bus with an appropriate conductor is paramount for ensuring electrical safety and compliance with ABYC standards