How should the size of a system bonding jumper be determined when it is a wire type?

The correct method for determining the size of a system bonding jumper when it is a wire type involves using Table 250.102(C)(1). This table provides the appropriate wire sizes for bonding jumpers based on the size of the grounding electrode conductor or the service conductors. The specifications in this table take into account the need for proper current-carrying capacity to ensure effective grounding of the electrical system.

Using Table 250.102(C)(1) is critical to maintain safety and compliance with the National Electrical Code (NEC), since the selected size must be capable of handling the fault currents that may occur in the system. An inadequate size could lead to failures or safety hazards, making it essential to follow the established guidelines.

In contrast, other options like determining size based on total voltage or employing a generalized 10% rule do not provide the specificity required for ensuring proper system function and safety as outlined by regulatory standards. Also, stating that any size can be used if grounded neglects the importance of proper sizing for electrical safety and performance.