A lighting panel protected by 150-ampere non-timed delay fuses requires what minimum size for the aluminum equipment grounding conductor?

For a lighting panel that is protected by 150-ampere non-timed delay fuses, determining the minimum size of the aluminum equipment grounding conductor is based on the National Electrical Code (NEC) guidelines.

The NEC specifies that the size of the equipment grounding conductor must be based on the size of the overcurrent protection device (fuses or circuit breakers) and the material of the conductor. For aluminum conductors, the table in the NEC provides specific sizing requirements depending on the ampacity of the circuit protection.

In this scenario, a 150-ampere protection level generally calls for a minimum grounding conductor size of 4 AWG aluminum. This takes into account the need for an effective ground-fault current path to ensure safety and reduce the risk of electric shock or fire in the event of a fault condition.

The choice of 4 AWG as the minimum size is based on providing adequate capacity to handle any possible ground fault currents while ensuring the safe operation of the electrical system. Selecting a conductor size smaller than this may not adequately protect against these potential faults, leading to increased risk in the electrical system's integrity.