Article 647 Sensitive Electronic Equipment
Informational Note No. 2: These requirements limit the impedance of the ground fault return path where only 60 volts apply to a fault condition instead of the usual 120 volts.
- All 15- and 20-ampere receptacles shall be GFCI protected.
- All receptacle outlet strips, adapters, receptacle covers, and faceplates shall be marked with the following words or equivalent:
WARNING — TECHNICAL POWER
Do not connect to lighting equipment.
For electronic equipment use only.
60/120 V. lΦac
The warning sign(s) or label(s) shall comply with 110.21(B).
- A 125-volt, single-phase, 15- or 20-ampererated receptacle having one of its current-carrying poles connected to a grounded circuit conductor shall be located within 1.8 m (6 ft) of all permanently installed 15- or 20-ampererated 60/120-volt technical power-system receptacles.
- All 125-volt receptacles used for 60/120-volt technical power shall have a unique configuration and be identified for use with this class of system.
Exception: Receptacles and attachment plugs rated 125-volt, single-phase, 15- or 20-amperes, and that are identified for use with grounded circuit conductors, shall be permitted in machine rooms, control rooms, equipment rooms, equipment racks, and other similar locations that are restricted to use by qualified personnel.