Code Change Summary: Revised code language on equipment grounding HVAC equipment.

During the 2017 code cycle, a public input (code change proposal) was accepted to require a wire type equipment grounding conductor for rooftop HVAC equipment supplied by metal raceways that use non-threaded fittings.

The idea was to address a common occurrence where a non-threaded raceway such as EMT was installed and the fittings either come loose or were never made up wrench-tight to begin with. In this case, the equipment grounding path is compromised, and the metal raceway may not provide a reliable return path during a ground-fault condition.

One problem with the 2017 code language was that it only applied to rooftop “multimotor and combination-load equipment”. The original intent was that it applies to all outdoor rooftop HVAC equipment. In the 2020 NEC^®, this was cleared up by replacing the words “multimotor and combination-load equipment” with the word “equipment”.

Another problem was the 2017 language only applied to raceway systems that use non-threaded “fittings”. A literal application of the text would exempt EMT with compression connectors since they have threads. This was not the original intent. The intent of the 2017 language was to allow threaded raceway systems such as Intermediate Metal Conduit (IMC) or Rigid Metal Conduit (RMC) to be exempt from requiring a wire type equipment grounding conductor since both IMC and RMC are threaded metal raceways and less likely to come apart when jarred or tripped on.

In the 2020 NEC^®, this was cleared up by requiring a wire type equipment grounding conductor to be installed in outdoor portions of metallic raceway systems that use “compression-type” fittings. This will apply to all EMT, and any IMC or RMC that has been cut and is coupled or connected with a compression fitting.

Below is a preview of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC^® edition of NFPA 70.