I.L. 29C507
Effective May 2000
Cutler-Hammer
Installation Instructions for the Digitrip OPTIM 550 3-Pole
Trip Unit Installation and Operation with K-Frame Series C
Circuit Breakers
Table of Contents
Description Page
1.0 General Information . . . . . . . . . . . . . . . . . . . . . .1
2.0 UL Listed Devices . . . . . . . . . . . . . . . . . . . . . . . .2
3.0 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
4.0 Principle of Operation . . . . . . . . . . . . . . . . . . . . .5
4.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
4.2 Overload Trip . . . . . . . . . . . . . . . . . . . . . . . . . . .6
5.0 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
5.1 Functional Field Testing . . . . . . . . . . . . . . . . . . .6
5.2 Performance Testing for Ground
Fault Trip Units . . . . . . . . . . . . . . . . . . . . . . . . . .6
5.2.1 Code Requirements . . . . . . . . . . . . . . . . . . . . . .6
5.2.2 Standards Requirements . . . . . . . . . . . . . . . . . .6
5.2.3 General Test Instructions . . . . . . . . . . . . . . . . . .6
6.0 Rating Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
7.0 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
7.1 Series C K-Frame Molded Case
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . .8
7.2 Internal Accessories . . . . . . . . . . . . . . . . . . . . . .8
DEATH, SEVERE PERSONAL INJURY, OR SUB-
STANTIAL PROPERTY DAMAGE CAN RESULT
FROM CONTACT WITH ENERGIZED EQUIPMENT.
DO NOT ATTEMPT TO INSTALL OR PERFORM
MAINTENANCE ON EQUIPMENT WHILE IT IS ENER-
GIZED. ALWAYS VERIFY THAT NO VOLTAGE IS
PRESENT BEFORE PROCEEDING WITH THE TASK,
ALWAYS FOLLOW GENERALLY ACCEPTED
SAFETY PROCEDURES.
CUTLER-HAMMER IS NOT LIABLE FOR THE
MISAPPLICATION OR MISINSTALLATION OF
ITS PRODUCTS.
The user is cautioned to observe all recommendations,
warnings, and cautions relating to the safety of person-
nel and equipment as well as all general and local
health and safety laws, codes, and procedures.
WARNING
The recommendations and information contained herein
are based on Cutler-Hammer experience and judge-
ment, but should not be considered to be all-inclusive or
covering every application or circumstance which may
arise. If any questions arise, contact Cutler-Hammer for
further information or instructions.
1.0 GENERAL INFORMATION
The Digitrip OPTIM 550, illustrated in Figure 1-1, is an
electronic trip unit that incorporates a microprocessor-
based custom application specific integrated circuit
design for use with the Series C K-Frame Molded Case
Circuit Breakers.
The Digitrip OPTIM 550 provides true RMS current
sensing for proper correlation with thermal characteris-
tics of conductors and equipment. Interchangeable rat-
ing plugs are provided to establish the continuous cur-
rent rating of each circuit breaker.
Figure 1-1 Digitrip OPTIM 550 Trip Unit for 3-Pole
K-Frame Series C Circuit Breaker
