Article 645 Information Technology Equipment

Informational Note No. 1: For further information, see NFPA 75-2017, Standard for the Fire Protection of Information Technology Equipment, which covers the requirements for the protection of information technology equipment and information technology equipment areas.

Informational Note No. 2: Text that is followed by a reference in brackets has been extracted from NFPA 75-2017, Standard for the Fire Protection of Information Technology Equipment. Only editorial changes were made to the extracted text to make it consistent with this Code.

Abandoned Supply Circuits and Interconnecting Cables. Installed supply circuits and interconnecting cables that are not terminated at equipment and not identified for future use with a tag.

Critical Operations Data System. An information technology equipment system that requires continuous operation for reasons of public safety, emergency management, national security, or business continuity.

Remote Disconnect Control. An electric device and circuit that controls a disconnecting means through a relay or equivalent device.

Zone. A physically identifiable area (such as barriers or separation by distance) within an information technology equipment room, with dedicated power and cooling systems for the information technology equipment or systems.

1. Wiring methods: 300.22(C)(1)
2. Class 2, Class 3, and PLTC cables: 725.135(C) and Table 725.154
3. Fire alarm systems: 760.53(B)(2), 760.135(C), and Table 760.154
4. Optical fiber cables: 770.113(C) and Table 770.154(a)
5. Communications circuits: 800.113 and Table 800.154(a)
6. CATV and radio distribution systems: 800.113 and Table 800.154(a)

Informational Note: See Part I of Article 100, Definitions, for a definition of communications equipment.

1. Disconnecting means complying with 645.10 are provided.
2. A heating/ventilating/air-conditioning (HVAC) system is provided in one of the methods identified in 645.4(2) a or b.
   1. A separate HVAC system that is dedicated for information technology equipment use and is separated from other areas of occupancy; or
   2. An HVAC system that serves other occupancies and meets all of the following:
      1. Also serves the information technology equipment room
      2. Provides fire/smoke dampers at the point of penetration of the room boundary
      3. Activates the damper operation upon initiation by smoke detector alarms, by operation of the disconnecting means required by 645.10, or by both

      Informational Note: For further information, see NFPA 75-2017, Standard for the Fire Protection of Information Technology Equipment, Chapter 10, 10.1, 10.1.1, 10.1.2, and 10.1.3.

3. All information technology and communications equipment installed in the room is listed.
4. The room is occupied by, and accessible to, only those personnel needed for the maintenance and functional operation of the installed information technology equipment.
5. The room is separated from other occupancies by fire-resistant-rated walls, floors, and ceilings with protected openings.

   Informational Note: For further information on room construction requirements, see NFPA 75-2017, Standard for the Fire Protection of Information Technology Equipment, Chapter 5.

6. Only electrical equipment and wiring associated with the operation of the information technology room is installed in the room.

Informational Note: HVAC systems, communications systems, and monitoring systems such as telephone, fire alarm systems, security systems, water detection systems, and other related protective equipment are examples of equipment associated with the operation of the information technology room.

1. Power-supply cords shall not exceed 4.5 m (15 ft).
2. Power cords shall be listed and a type permitted for use on listed information technology equipment or shall be constructed of listed flexible cord and listed attachment plugs and cord connectors of a type permitted for information technology equipment.

Informational Note: One method of determining if cords are of a type permitted for the purpose is found in UL 60950-1-2007, Safety of Information Technology Equipment — Safety — Part 1: General Requirements; or UL 62368-1-2012, Audio/Video, Information and Communication Technology Equipment — Part 1: Safety Requirements.

(a) The supply conductors shall be installed in accordance with the requirements of 300.11.

(b) In addition to the wiring methods of 300.22(C), the following wiring methods shall also be permitted:

1. Rigid metal conduit
2. Rigid nonmetallic conduit
3. Intermediate metal conduit
4. Electrical metallic tubing
5. Electrical nonmetallic tubing
6. Metal wireway
7. Nonmetallic wireway
8. Surface metal raceway with metal cover
9. Surface nonmetallic raceway
10. Flexible metal conduit
11. Liquidtight flexible metal conduit
12. Liquidtight flexible nonmetallic conduit
13. Type MI cable
14. Type MC cable
15. Type AC cable
16. Associated metallic and nonmetallic boxes or enclosures
17. Type TC power and control tray cable

1. Supply cords of listed information technology equipment in accordance with 645.5(B).
2. Interconnecting cables enclosed in a raceway.
3. Equipment grounding conductors.
4. Where the air space under a raised floor is protected by an automatic lire suppression system, in addition to wiring installed in compliance with 725.135(C), Types CL2R, CL3R, CL2, and CL3 and substitute cables including CMP, CMR, CM, and CMG installed in accordance with 725.154(A) shall be permitted under raised floors.

   Informational Note: Figure 725.154(A) illustrates the cable substitution hierarchy for Class 2 and Class 3 cables.

5. Where the air space under a raised floor is not protected by an automatic fire suppression system, in addition to wiring installed in compliance with 725.135(C), substitute cable Type CMP installed in accordance with 725.154(A) shall be permitted under raised floors.
6. Listed Type DP cable having adequate fire-resistant characteristics suitable for use under raised floors of an information technology equipment room.

Informational Note: One method of defining fire resistance is by establishing that the cables do not spread fire to the top of the tray in the "UL Flame Exposure, Vertical Tray Flame Test" in UL 1685-2015, Standard for Safety for Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables. The smoke measurements in the test method are not applicable.

Another method of defining fire resistance is for the damage (char length) not to exceed 1.5 m (4 ft 11 in.) when performing the CSA "Vertical Flame Test — Cables in Cable Trays," as described in CSA C22.2 No. 0.3-2014, Test Methods for Electrical Wires and Cables.

1. Where the air space under a raised floor is protected by an automatic fire suppression system, optical fiber cables installed in accordance with 770.113(C), Types OFNR, OFCR, OFN, and OFC shall be permitted under raised floors.
2. Where the air space under a raised floor is not protected by an automatic fire suppression system, only optical fiber cables installed in accordance with 770.113(C) shall be permitted under raised floors.

Informational Note: Securement requirements for raceways and cables not listed as part of, or for, information technology equipment are found in 300.11.

1. Date identified for future use
2. Date of intended use
3. Information relating to the intended future use

Exception: Installations complying with Article 685.

Informational Note: For further information, see NFPA 75-2017, Standard for the Fire Protection of Information Technology Equipment.