9
Instruction Booklet
IB 52-01-TE
Effective October 2010
Instructions for the Eaton Type CM52
Network Protectors 800 to 4500 Amperes
EATON COrPOrATION www.eaton.com
9 IB -52-01-TE
Effective 11/05/08 (super cedes 11/19/03) IB 52-01-TE
9
4.4.2
Anti-Close Feature
The CM52 circuit breaker cont ains an auxiliary
relay that is energized when the MPC series
relay calls for a trip. This relay has a contact in
series with the motor circuit, isolating the motor
closing scheme.
4.4.3
Trip and Lockout
The anti-close relay also provides an automatic
lockout feature wh en an extern al remote trip is
applied. A remote trip can be wired from the din
rail terminal block in the rel ay module. The
wires for a remote trip and/or lockout provision
are l abeled on the wiring di agram p rovided with
the unit.
4.5 ARC CHAMBERS
The CM52 circuit breaker utilizes arc ch ambers
to insulate and isolate individual poles from one
another, from the rest o f th e circuit breaker, and
from operating personn el. Arc chambers are
molded and integral parts of th e circuit break er
frame. Enclosed within each arc chamber is an
arc chute that mounts over each set o f p rimary
contacts.
After the main contacts part, any remaining
current is driven to the arcing contacts. The
main contacts separate, th e moving arcing
contacts discharg e into the arc chute plates while
the integral arc runn er also helps to draw the arc
into the arc chute.
4.5.1
Arc Chute Removal
(s ee also 2.1.2.1)
The CM52 arc chute mounts down over the
arcing cont act. Alternating V-sh aped arc chute
plates attract the arc and interrupt it. The top arc
plate, which is a p art o f the arc chute itsel f, also
helps to attract the arc away from the moving
arcing cont act and up into the arc chute’s V-
shaped plat es. Arc chut e compon ents are
assembled in an insulating jack et that is
removable from the top of the circuit breaker.
Each arc chut e has a baffled top cov er. One
single, captive 5/32” Allen head bolt holds the
arc chute in place. Loosen bolt and slide top
frame o f the arc chute rearward. Pull the arc
chute free from the breaker.
Fig. 13a
Loosen Arc Chute captive bolt
Fig. 13b
Remove Arc Chute
4.6
ELECTRONIC TRIPPING SYSTEM
The CM52 circuit break er utilizes a four p art
tripping system.
-
MPC series Relay
-
Current Transform er
-
Trip Actuator
-
Indicating
Diagnostic
Module
(IDM)
MPC series Relay
- Refer to IB 35-581B.
Current Transformers
(see also 2.1.2.2)
-
The
current sensors are mounted on the lower rear set
of breaker stabs and are protect ed by a glass
polyester shield. The shield has three ports from
which can be viewed the sensor ratios. Each CT
