Under what condition do tools and appliances need not be bonded to ground?

Tools and appliances are designed with safety standards to minimize the risk of electrical shock or fire hazards. The principle of bonding to ground serves to protect users in case of a fault or malfunction.

In situations where a double insulated portable Ground Fault Circuit Interrupter (GFCI) is used, the device provides an additional layer of protection by continuously monitoring the current balance between the hot and neutral wires. If an imbalance is detected—often due to current leakage from an appliance or tool—the GFCI quickly cuts off power to prevent electrical shock. Because double insulation effectively mitigates the risk of electric shock without the need for grounding, tools and appliances can operate safely without being bonded to ground when using this form of GFCI.

In contrast, other options may not provide the same level of safety. For example, use with a portable generator generally requires a bonding process due to the inherent risks of electromagnetic interference, while battery-powered devices can still pose hazards if not properly managed. Finally, the presence of a grounding rod does not negate the need for bonding, as it merely provides an additional ground point but does not ensure that all appliances are sufficiently grounded to prevent shock hazards.