While the shock hazard created by a reverse polarity bootleg ground (RPBG) outlet is bad enough, if multiple appliances or gear are plugged into separate electrical outlets — one of which is wired incorrectly as a RPBG — then any signal or control cable between the appliances will be subject to short circuit fault currents between the correctly wired outlet’s ground and the RPBG outlet’s ground, which is actually connected to the incoming hot wire. Because these signal cables are typically small diameter (22 gauge), they don’t offer a low enough impedance to created sufficient fault current that will trip a 15A or 20A circuit breaker. The interconnecting gear often becomes the “fuse” heating up red hot before a wire or circuit board trace melts and opens the ground fault path (Photo).

It’s important to note that this equipment failure does not remove the electrocution hazard, given the fact that a technician handling the gear will be still be touching a chassis that is directly connected to the incoming 120V line.