Which statement is correct regarding bonding a grounding conductor when using EMT from service to a water pipe?

Which statement is correct regarding bonding a grounding conductor when using EMT from service to a water pipe?

• A. It may be omitted if the pipe is insulated.
• B. The GEC must be connected to the water pipe only at the device.
• C. Bonding is not required if the system is grounded.
• D. The EMT raceway must be electrically bonded to both the service and the water pipe.

Answer: (D)

Bonding a metal raceway like EMT creates a continuous, low-impedance path to ground. When the service feed travels through EMT all the way to a water pipe, the EMT itself can serve as part of the grounding path only if it is bonded to the service equipment grounding conductor and to the water pipe. This ensures fault currents have a reliable path back to the source and keeps the water pipe at the same electrical potential as the rest of the grounding system, which reduces shock risk and helps the overcurrent protective device trip properly. Omitting bonding because the pipe is insulated would leave potential differences and a broken ground path. Connecting the grounding conductor only at the water pipe or assuming bonding isn’t needed if the system is grounded also misses the requirement to maintain continuity along the EMT run. The key is bonding the EMT to both the service and the water pipe so the entire path remains bonded.

Bonding a metal raceway like EMT creates a continuous, low-impedance path to ground. When the service feed travels through EMT all the way to a water pipe, the EMT itself can serve as part of the grounding path only if it is bonded to the service equipment grounding conductor and to the water pipe. This ensures fault currents have a reliable path back to the source and keeps the water pipe at the same electrical potential as the rest of the grounding system, which reduces shock risk and helps the overcurrent protective device trip properly.

Omitting bonding because the pipe is insulated would leave potential differences and a broken ground path. Connecting the grounding conductor only at the water pipe or assuming bonding isn’t needed if the system is grounded also misses the requirement to maintain continuity along the EMT run. The key is bonding the EMT to both the service and the water pipe so the entire path remains bonded.