Code Change Summary: Additional code language specifies how GFPE testing (ground-fault protection of equipment) must be done.

One of the most important performance tests for newly-installed electrical equipment is the testing of GFPE. Performance testing must be done after the system is installed but before it is energized.

Not all equipment contains a GFPE device. For each service disconnect rated 1000 amperes or more, section 230.95 requires GFPE in solidly grounded wye electric services of more than 150 volts to ground but not exceeding 1000 volts phase-to-phase. Similar language is found in 215.10 for feeder disconnects and 210.13 for branch circuit disconnects.

When GFPE is installed, section 230.95(C) requires specific performance testing to make sure the device is functioning as intended. Until now, the testing was only required to be done in accordance with the manufacturer’s testing instructions and no additional details were provided. It is often thought that the push-to-test feature on the device is the proper way to comply with the test requirements in 230.95(C). Unfortunately, the push-to-test feature does not properly test all aspects of the GFPE device which is required in the initial commissioning of the switchgear.

For example, pressing a “push-to-test” button only initiates a test-current flow on a portion of the components, rather than all of the components that comprise the ground-fault system. It does not sufficiently test the wiring, the polarity, the current sensor primary windings, and several other critical aspects of the ground-fault protection system.

A primary current injection test must be done to test all other features of the GFPE that the push-to-test feature does not address.

Now, the 2017 NEC^® provides specific language requiring primary injection testing for the GFPE device.

Below is a preview of Article 230. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2017 NEC^® edition of NFPA 70.