What must be done with the grounded conductor of an AC system operating at 1000 volts or less?

For an AC system operating at 1000 volts or less, the grounded conductor must be connected to the service disconnecting means. This connection is essential for ensuring safety by providing a clear and consistent path for fault currents to return to the ground, which helps to mitigate the risk of electric shock or fire.

When the grounded conductor is bonded to the service disconnecting means, it facilitates the operation of overcurrent protection devices, such as circuit breakers or fuses. In the event of a fault that causes the current to stray from its intended path, the grounded conductor ensures that the overcurrent device can detect this anomaly and interrupt the circuit, thereby protecting both equipment and personnel.

Additionally, proper connection of the grounded conductor to the service disconnecting means helps comply with the National Electrical Code (NEC) requirements concerning grounding and bonding practices, further promoting safety and reliability in electrical installations.