18.) Emergency, Legally Required and Optional Standby Signs
700.8, 701.9 and 702.8; Signs
There are two types of signs required when there is an on-site emergency, legally required standby or optional standby source. The first sign is a requirement of "(A)" in all three sections. It must be placed at the location of the service entrance equipment and identify the location and type of the onsite power source.
Both 700.8(A) and 701.9(A) include an exception for the sign where individual unit equipment (battery packs) are the onsite power source.
The second sign is a requirement of "(B)" in all three sections and it applies where the grounded circuit conductor connected to the power source is connected to a grounding electrode conductor at a location that is remote from the power source. One common installation where the grounding connection to a grounding electrode conductor that is remote from the power source is where the power source is not installed as a "separately derived system" (see Article 100 definition). In this application the onsite power source grounded conductor has a solid connection to the normal system grounded conductor (not switched by the transfer switch) and the grounding connection to the grounding electrode conductor is typically being made to the normal supply grounded conductor at the service or other normal supply location.
Where the requirement of "(B)" applies, the sign must be placed at the grounding location which is where the grounding electrode conductor connects to the grounded conductor. The sign must identify any emergency, legally required standby or optional standby sources as well as any normal sources that are connected at that location.