Current Sensor Replacement; Figure 103. Current Sensor Cover In Place Over Sensors; Figure 104. One Current Sensor Shown Removed And - Eaton SBN-508 Instructions For Installation, Operation And Maintenance

Instructions for Installation, Operation and
Maintenance of Magnum SB Insulated Case
Low Voltage Power Circuit Breakers

Current Sensor Replacement

REMEMBER THAT THE TRIP UNIT'S RATING PLUG AND THE CIRCUIT
BREAKER'S CURRENT SENSORS MUST HAVE MATCHING RATINGS.
The three current sensors are installed at the rear of the circuit
breaker on the lower terminals . A cover with sensor rating
viewing windows covers the sensors and is held in place
with screws (Figure 103) . Remove the cover by removing the
screws .

Figure 103. Current Sensor Cover in Place Over Sensors

If the circuit breaker is a drawout configuration, the lower
primary disconnect finger clusters and the vertical adaptors
must first be removed from frame sizes up to 3000A . On the
3000A frame, both the upper and lower primary disconnects
and vertical adaptors must be removed . Each primary
disconnect finger cluster is removed by loosening the two hex-
head bolts with a 10 mm wrench . These bolts do not have to be
completely removed to slide the primary disconnects off of the
terminals . Remove the vertical adaptors next from the circuit
breaker terminals by removing the two or three 10 mm bolts
holding them in place (Figure 104) .
NOTICE
Current Sensor
Cover
Instructional Leaflet
The current sensors are removed by pulling them off of the
terminals and unplugging the wiring plugs from the sensors
(Figure 104) .
Install new current sensors by connecting the wiring plugs
to the sensors and sliding the sensors over the terminals .
Reinstall the cover over the sensors and secure in place with
the screws previously removed .
Reinstall the previously removed vertical adaptors to the
terminals using the removed hardware and 40 ft-lb of tightening
torque . Make sure the vertical adaptors are square to the
rear housing . Slip the primary disconnects on to the vertical
adaptors . Make sure the primary disconnects are fully inserted
on to the vertical adaptors . Tighten the two retention bolts to
40 in-oz of torque . Properly engaged and secured retention
bolts should engage the slots or holes in the vertical adaptors .
Wiring Plug

Figure 104. One Current Sensor Shown Removed and

Disconnected
EATON CORPORATION www.eaton.com
IB2C12063H03
Effective March 2012
Vertical
Adaptor
Current
Sensor
67