Question
Can information technology equipment be cord-and-plug connected if the cord is either hard usage type or portable power cable type? Is such IT equipment required to be marked as being suitable for cord-and-plug connection before such connection be utilized? Is there a maximum length for power-supply cords used to connect IT equipment as well as for cables that interconnect separate IT equipment? JP
Answer
Figure 1. Typical IT equipment, cord-and-plug connected under a raised floor.First, we must assume that the information technology equipment in question does qualify as IT equipment by meeting all of the six conditions listed at 645.4. If the IT equipment in question does not meet all of the special conditions of 645.4, then this equipment would be subject to the provisions of Chapters 1 through 4 of the NEC.
Section 645.5(B)(2) covers the type of cords that are permitted for IT equipment and the terms “hard usage” and “portable power cable” are not used in this section. This subsection does require IT power cords to be listed and of a type permitted for use on listed information technology equipment. Section 645.5(B)(2) also permits power cords constructed of listed flexible cord and listed attachment plugs and cord connectors of a type permitted for information technology equipment. Section 645.4(3) requires all information technology equipment to be listed and the determination of whether the IT equipment can be cord-and plug-connected is better suited for the product standards and the product certifications rather than the NEC. From the UL White Book Category “NWGQ” the following is stated, “When listed equipment intended for use with a detachable power-supply cord is not provided with such a cord, a cord suitable for connection of the equipment to the branch circuit should be separately provided.” The length of the power-supply cord for IT equipment is limited to 4.5 m (15 ft) by Section 645.5(B)(1). Interconnecting cables are not limited to 4.5 m (15 ft) like the power-supply cables as noted at 645.5(C). Interconnecting cables are required to be listed but the length of the interconnecting cable is not restricted by the NEC.