Page 26
MAINTENANCE
RECOMMENDED INSPECTION AND
MAINTENANCE TYPES
NOTE:
Refer to the SAFETY section of this
manual for important information.
A. Acceptance Inspection
This inspection confirms that the circuit
breaker unit is complete, correct as specified,
and undamaged from shipment. The
procedure for this inspection is outlined in the
RECEIVING, INSPECTION AND HANDLING
section of this manual.
B. Patrol Inspection
Inspection is made of the condition of the
circuit breaker while it is energized. Check
that no unusual sounds or smells exist
externally.
Inspection Frequency: Once every 6 months
C. Periodic Inspection
Inspection is performed wth the circuit
breaker de-energized. The lubrication of
sliding and rotating parts is checked and the
mechanism is lubricated if needed.
Inspection Frequency: Once every 1-3 years
or every 3000 operations (normal). Once
every 6 years (detailed).
Refer to Table 2 for the schedule of Periodic
Inspections.
D. Unscheduled Inspection
Inspections are implemented as required.
Inspection Frequency: As needed
NOTE:
The inspection frequency and points
to be inspected may vary from the
above recommendations depending
on the status of use, frequency of
switching, amount of current
interrupted and other factors.
Table 1 Tightening Torques
Screw
Nominal
Dia.
Tightening Torque
M4
15-20 kgf-cm
13-17 in-lb
M5
30-40 kgf-cm ()
26-34 in-lb
M6
50-65 kgf-cm ()
43-56 in-lb
M8
120-150 kgf-cm ()
9-11 ft-lb
M10
250-315 kgf-cm ()
18-23 ft-lb
M12
450-565 kgf-cm ()
32-41 ft-lb