You've correctly identified a significant change in the 2020 NEC regarding signage for optional standby power sources. Let's break down the implications of this change and analyze whether the generator inlet itself needs a sign.

Key Differences Between 2017 and 2020 NEC 702.7



2017 NEC

Required a sign at the service-entrance equipment indicating the type and location of

each on-site optional standby power source. 2020 NEC



Commercial/Industrial

Still requires a sign at the service-entrance equipment indicating the type and location of

each on-site optional standby power source. This requirement is essentially unchanged from 2017 for these installations. One- and Two-Family Dwelling Units

Requires a sign at the disconnecting means required in 230.85 (this generally refers to the outside disconnect) that indicates the location of

each permanently installed on-site optional standby power source disconnect or means to shut down the prime mover as required in 445.18(D).

Interpreting the 2020 NEC for Generator Inlets

Here's the critical point: The 2020 NEC for one- and two-family dwellings focuses on the disconnect or shutdown means of the standby power source.



Is the Generator Inlet the "Optional Standby Power Source Disconnect"? Generally,

no. The generator inlet is a connection point, not a disconnecting means. A disconnect is a switch or breaker that interrupts the electrical circuit. The inlet allows for the connection of the generator's power.

What IS the "Optional Standby Power Source Disconnect"? This would typically be the breaker or switch that isolates the generator power from the load. It is generally located in the transfer switch, or in line with the generator.

Therefore, based on the wording of the 2020 NEC, a sign at the service equipment indicating the location of the generator inlet itself is generally NOT required.

However, A sign is still needed to indicate the location of the transfer switch, or other means of disconnecting the generator.

Potential Confusion and Best Practices

Even though not strictly required, it's good practice to label the generator inlet clearly as such. This helps prevent confusion, especially for future homeowners or service personnel. A simple label like "Generator Inlet - 240V" (or whatever voltage is applicable) is recommended.

Where is a Sign Required? 230.85 Disconnecting means. Under the 2020 NEC, 230.85 requires an emergency disconnect on all new one- and two-family dwelling units. The required signage for an optional standby system for one- and two-family dwelling units must be placed at this disconnect.

In conclusion: While the 2017 NEC was broader in its signage requirement, the 2020 NEC for one- and two-family dwellings is more specific. It emphasizes the disconnect or shutdown means of the generator, not just its location. Therefore, a sign specifically at the service equipment pointing to the inlet is no longer strictly required for dwelling units under the 2020 NEC*. However, proper labelling of the inlet itself and a sign at the disconnect means is still recommended for safety and clarity. Flag for review