Eaton Cutler-Hammer SJA User Manual

Effective 11/97
I.B. 48006
Cutler-Hammer
Instructions for Mechanical-Latch Attachments for Type
SJA, SJD, SJO and SJS Contactors, 360 or 720 Amperes
DANGER
HAZARDOUS VOLTAGE.
READ AND UNDERSTAND THIS MANUAL AND THAT
PERTAINING TO ITS ELECTRICALLY-HELD
CONTACTOR (SEE TABLE I) IN THEIR ENTIRETY
BEFORE INSTALLING OR OPERATING THE CON-
TROLLER. INSTALLATION, ADJUSTMENT, REPAIR
AND MAINTENANCE OF THIS TYPE OF EQUIPMENT
MUST BE PERFORMED BY QUALIFIED PERSONNEL.
A QUALIFIED PERSON IS ONE WHO IS FAMILIAR
WITH THE CONSTRUCTION AND OPERATION OF
THIS EQUIPMENT AND THE HAZARDS INVOLVED.
APPLICATION
These instructions apply to Type SJA, SJD, SJO and SJS
contactors that are fitted with mechanical-latch attach-
ments.
Fig. 1 Type SJO with Latch Attachment
CAUTION
A LATCHED CONTACTOR SHOULD BE APPLIED
ONLY WHEN NECESSARY, AND WITH DUE RE-
GARD TO THE POSSIBLE FAILURE MODES OF
THE SYSTEM, FOR EXAMPLE, A POWER LOSS
OR SOLENOID COIL FAILURE. ONCE LATCHED,
THE CONTACTOR WILL REMAIN CLOSED, AL-
LOWING A FAILURE. SINCE POWER IS RE-
QUIRED TO TRIP THE UNLATCH SOLENOIDS,
PROVISION SHOULD BE MADE FOR MANUAL
TRIPPING, USING THE MECHANICAL TRIP ARM,
OR A STANDBY POWER SUPPLY, SHOULD THE
MAIN CONTROL POWER BE LOST.
OPERATION
When a Type SJ contactor with latch attachment is open,
the latch mechanism is unlatched and de-energized.
When the coil of a latch contactor is momentaily ener-
gized, its armature closes, closing the main power
TABLE I. REFERENCE MATERIAL
Electrically-Held Ampere Instruction
Contactor Type Rating I.L. or I.B.
Type SJA 360A I.B. 48002
Type SJA 720A I.B. 48005
Type SJD 360A I.B. 48004
Type SJO 360A I.L. 16-200-33
Type SJO 720A I.L. 17047
Type SJS 360A I.B. 48003
contacts. As the armature seals to the magnet, a spring
pushes the latch arm up into position behind the arma-
ture to hold it closed mechanically, at the same time an
auxiliary coil-clearing contact (L63) on the contactor
opens the contactor coil circuit to de-energize the
contactor magnet. Although the magnet is de-energized,
the contactor will remain latched closed until a trip coil is
energized or the latch is tripped mechanically by a push
against its trip arm.

Eaton Cutler-Hammer SJA Specifications

General

Frame Size	SJA
Product Name	SJA
Voltage	600V AC
Poles	2, 3
Standards	UL, CSA, IEC

Summary

Safety Information and Application

Application Scope

Defines the types of contactors these instructions apply to.

Hazardous Voltage Warning

Emphasizes danger of hazardous voltage and need for qualified personnel.

Contactor Latching Caution

Advises caution when applying latched contactors and making provisions for manual tripping.

Operation and Control

Mechanical Latch Operation

Explains how the contactor closes and latches mechanically when the coil is energized.

Trip Solenoid and Control

Describes trip solenoid function, sensitivity, and control power requirements.

Installation and Manual Operation

Manual Unlatch Operator Installation

Details the procedure and parts for adding a manual unlatch operator.

Installation Safety Warning

Warns to open main disconnect and ensure power is off before working on contactor.

Mechanical Check-Out

Mechanical Latch Handling Caution

Compares latch to a mousetrap and advises care to protect fingers during check-out.

Electrical Check-Out

Maintenance and Troubleshooting

Failure To Latch Or Unlatch

Provides troubleshooting steps for when the contactor fails to latch or unlatch.

Failure To Remain Latched

Offers guidance on de-sensitizing the latch if nuisance unlatching occurs.