Mechanical Interlocks

Class 9999 / Refer to Catalog 9999CT9701

Mechanical Interlock

Type SM1

Type SM12

General: Type S contactors or starters can be mechanically interlocked so that only one device is energized at a time. The mechanical interlock is an interference (non-jamming) type, locking at the beginning of the stroke of any starter or contactor.

Type S Sizes 00, 0, 1, and 2—The mechanical interlock is mounted on the underside of the reversing baseplate. Two pins extend from the mechanical interlock through openings in the baseplate and engage the contact carrier of each contactor. Two styles of mechanical interlocks are used: one version for three pole contactors, a different version for four or five pole contactors. When adding a power pole to the left side of an existing Size 0, 1, or 2 three-pole reversing contactor, a new mechanical interlock must also be installed. When added to the right side only, the power pole is not mechanically interlocked with the left-hand contactor.

Type S Sizes 3 and 4—The mechanical interlock is separate from the mounting pan on Sizes 3 and 4. Cams on the mechanical interlocks are operated by the contact carrier of each contactor. The mechanical interlock is attached to the underside of the two contactor baseplates on Sizes 3 and 4.

note

The mechanical interlock kits in Mechanical Interlock for Two Contactors can be used to interlock 2–5 pole contactors. Mechanical interlocks for horizontal and vertical arrangement are listed in various pole arrangements.
Mechanical interlock Types SM1 through SM10 for Sizes 00-2 devices use overload relay mounting brackets to support the overload relay portion of the starter. See Overload Relay Mounting Bracket.

Mechanical Interlock for Two Contactors

  

Contactor
NEMA Size

Class 9999
Type

Horizontal
Type SM1 for Size 00–1
Type SM12 for Sizes 3 & 4

Horizontal
Type SM12 for Sizes 3 & 4

Vertical
Type SM10 for Size 2

00, 0, 1


0, 1


0, 1


0, 1


0, 1

SM1

Horizontal
Type SM8 for Size 2
Type SM12 for Sizes 3 & 4

Vertical

Vertical

2


2


2


2


2


3


3, 4


4


SM8


SM10


SM12

Overload Relay Mounting Bracket

Overload Relay Mounting Bracket

Kit Description

Class 9999
Type

Bracket for one overload relay used with horizontal mechanical
  interlocks, Types SM1 through SM10

Bracket for two overload relays used with vertical mechanical interlocks,
  Type SM10

SO12

How to Order

To Order Specify:

Catalog Number

  • Class Number

  • Type Number

Class

Type

9999

SM1

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