NEC 2023 702.5 - Listing of Transfer Equipment

[ron]

In case anyone in the forum was part of the code change in 2023, requiring Interconnection or transfer equipment shall be required for all standby systems subject to the requirements of this article. Equipment shall be suitable for the intended use and shall be listed, designed, and installed so as to prevent the inadvertent interconnection of all sources of supply in any operation of the equipment.

For a free standing transfer switch or one incorporated in a switchboard/switchgear lineup, is a UL 891 or 1558 listing compliant for the transfer equipment, or does it need to be UL 1008 listed?

Because it says suitable for the intended use and shall be listed, it would seem to me that it needs to be listed as a transfer switch (1008) and not a switchboard or switchgear.

Any thoughts on the issue?

 

[jim dungar]

Because it says suitable for the intended use and shall be listed, it would seem to me that it needs to be listed as a transfer switch (1008) and not a switchboard or switchgear.

Wouldn't listed transfer schemes be considered transfer equipment. If not what how could you transfer at MV?

 

[ron]

Wouldn't listed transfer schemes be considered transfer equipment. If not what how could you transfer at MV?

MV transfer would be UL 1008A.

MV is special because the code (2026 version) doesn't even require listing of MV switchgear until 2029 or 2032, depending on the voltage.