620.65 Signage.
Code Change Summary: New code section requires signage on selectively coordinated overcurrent devices for elevator equipment.
In the 2020 NEC®, new field marking requirements will alert those who are authorized to maintain, inspect, or work on an elevator system that the overcurrent devices for the system are selectively coordinated.
Selective coordination is required where more than one elevator driving machine disconnecting means is supplied by the same source. The idea behind selective coordination is to ensure that the overcurrent device closest to the fault opens before other upstream overcurrent devices open to clear the downstream fault.
A fault downstream of one elevator disconnecting means should not cause overcurrent devices supplying other elevators to open and disrupt all elevator service to the building.
This new field marking requirement will clearly identify when overcurrent devices are selectively coordinated which will aid those maintaining and servicing the system.
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.
2017 Code Language:
This code section did not exist.
2020 Code Language:
N 620.65 Signage. Equipment enclosures containing selectively coordinated overcurrent devices shall be legibly marked in the field to indicate that the overcurrent devices are selectively coordinated. The marking shall meet the requirements of 110.21(B), shall be readily visible, and shall state the following:
CAUTION: OVERCURRENT DEVICES IN THIS ENCLOSURE ARE SELECTIVELY COORDINATED. EQUIVALENT REPLACEMENTS AND TRIP SETTINGS ARE REQUIRED.