Connections, Connectors, and Couplings

DOE-HDBK-1092-98

Plugs and sockets for connecting any AC power source shall be NRTL approved for the application.

(Ref. ISA-S82.01-1992, Section 6.10.3.a)

AC power plugs and sockets shall not be used for purposes other than the connection of AC power.

Connectors operating at 50 V or greater shall be rated or recommended for their intended use.

Any connector used to provide power at 50 V or greater shall not allow personnel to make inadvertent

contact with the power source.

If plug pins of cord-connected equipment receive a charge from an internal capacitor, the pins shall

not be capable of rendering an electric shock or electric burn in the normal or the single fault condition

5 seconds after disconnection of the supply. (Ref. ISA-S82.01-1992, Section 6.10.3.c)

Plug-in type connectors intended to be connected and disconnected by hand shall be designed so that

the grounding conductor connection makes first and breaks last with respect to the other connections.

[See ISA-S82.01-1992, Section 6.11.2.g and NEC Section 250-99(a)]

The following applies for all AC power connectors within or external to electrical/electronic

enclosures:

1. There should be no exposed current-carrying parts except the prongs, blades, or pins.

2. The connector shall prohibit mating of different voltage or current rating than that for the device

intended.

3. All connectors must be protected against overcurrent in accordance with their rated ampacity.

(NEC Section 240-4)

4. Connectors must be NRTL approved for the application.

5. Use of MS, PT, or other non-approved connectors is not permitted except when justified to and

approved by the AHJ.

If conditions require the use of a non-NRTL listed or labeled connector, such as a "MS"(military

standard pin and socket type) or "PT" (similiar to "MS" but smaller) type, for input/output ac power,

a warning label should be affixed next to the connector stating: "WARNING - POWER MUST BE

REMOVED BEFORE CONNECTING/DISCONNECTING."

9.5.1.3 TERMINALS/LIVE PARTS

All terminals/live parts with a potential of 50 volts or greater shall be guarded to protect from

accidental contact or bringing conductive objects in contact with them (NEC Section 110-17).

Consult ANSI/ISA-S82.01-1988, Table 9-1 for spacing information regarding live parts.

All energized switching and control parts shall be enclosed in effectively grounded metal enclosures

and shall be secured so that only authorized and qualified persons can have access.

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