Installation Guide

Disconnecting Means Motor Control Solutions

Disconnecting Means

A disconnecting means must be provided for each incoming supply (branch) circuit,

and must open each ungrounded conductor of the supply circuit.

The disconnecting means may be one of the following:

• UL 489 inverse-time or instantaneous-trip circuit breaker

• UL 489 molded-case switch

• UL 98 switch unit, either open type or enclosed

For a motor starter, the disconnecting means could be a UL 508 Type E

self-protected combination motor controller.

The sizing of the disconnecting means must meet UL 508A Section 30.2.

An UL 508 manual motor controller or switch (such as the TeSys™ Vario device) is

certified for use on the load side of a motor's branch circuit protection. This is

commonly called a load break switch.

Industrial Machinery Requirements (NFPA 79 Section 5.3.3.1 and UL 508A Section 65, 66)

These requirements cover industrial control panels for industrial machinery

(NFPA 79-2002, Electrical Standard for Industrial Machinery). The following types

of machines are identified as industrial machinery:

• Metalworking machine tools, including machines that cut or form metal

• Plastics machinery, including injection molding, extrusion, blow molding,

specialized processing, thermoset molding, and size reduction machines

• Wood machinery, including woodworking, laminating, and sawmill machines

• Assembly machines

• Material handling machines, including industrial robots and transfer machines

• Inspection and testing machines, including coordinate measuring and

in-process gauging machines

An operating mechanism for the disconnecting means must have the following

characteristics:

• Readily accessible when the enclosure doors are in the open or closed position

• Installed so that its operation is not restricted by the enclosure door while in the

open position

• Operable independent of the door position without the use of accessory tools or

devices

• Lockable in the Off position independent of the door position; and, when the

mechanism is locked, the disconnect cannot be closed

The UL 98 TeSys GS family of disconnect switches meet these characteristics:

• The TeSys GS1 30 A disconnect switch requires the use of operating

mechanism kit GS1AD010.

• The TeSys GS2 family of disconnect switches provide these features from 60

to 400 A using operating mechanism kits GS2AD030N or GS2AD040N.

The UL 489 PowerPact™ Circuit breakers meet these characteristics when used in

conjunction with a Class 9422 or 9421L operating mechanism and 9421LH79 handle.