ON
Discharged
OFF
ON
OFF
Discharged
OFF
ON
ON
OFF
ON
Charged
OFF
Charged
OFF
ON
Safety Precautions
The following operations must be executed in turn before conducting the maintenance or overhaul of circuit breakers:
a. Circuit breaker opening operation to ensure the circuit breaker is in an opening state;
b. Disconnecting the upper-level knife switch (if any) to ensure the main circuit and secondary circuit are uncharged;
c. Circuit breaker discharging, opening operation to ensure the circuit breaker is in a discharging and opening state;
d. The components which the personnel might contact must be uncharged.
16.
Maintenance and Overhaul of Circuit Breaker
C
NA1
Air Circuit Breaker
P-094
P-093
NA1
Air Circuit Breaker
Keep Safe
Maintenance and overhaul cycle
Condition
General environment
Environment
Maintenance cycle
Overhaul cycle
Remarks
Every six months
Once per year
(
every six months for more
than 3 years of mounting
period)
The air should be always kept
clean and dry. There is no corrosive gas.
The temperature is in between -5
℃
~+40
℃
The humidity should conform to Specification
1.3 Operating Conditions c Requirement for
extreme atmosphere conditions.
Confirming to IEC60947-2
Requirement for general
environmental conditions.
Severe environment
Low temperature -5
℃~-40℃
or high
temperature 40
℃～
65
℃
or humidity
≥
90%
Places with more dust and corrosive gases
Every three months
Every month
Every six months
(
every three months for
more than 3 years of
mounting period)
Every three months
16.1 Maintenance of circuit breaker
16.1.1 Foreign objects (such as tools, wire leads or fragments, metal
objects) in the switchgear should be regularly cleared.
16.1.2 The dust on the circuit breaker must be regularly cleared to
maintain its good insulation.
16.1.3 The spring washers of the main circuit connecting bolts
，
the earthing bolts must be checked for whether they are
flattened and theconnection is firm.
16.1.4 Whether the opening or closing indication is correct and
reliable.
Closing charging
Opening charging
Closing discharging
Opening discharging
16.2 Overhaul of circuit breaker
16.2.1 Connecting and mounting inspection
It is proposed to refer to the following requirement for the torsional forces of main circuit and secondary circuit.
Fastener specification
M3
M4
M8
Torque requirement N·m
0.5~0.7
M10
M12
1.2
~
1
.7
16
~
26
36
~
52
61
~
94
16
.2.2 Insulating property test
The phase-phase and phase-earth insulation resistance, requirement
≥
20MΩ.
The insulation resistance test must be first done after overhaul and long-time
（
≥7days
）
of deenergization and before energization
again.
16
.2.3 Operating characteristic inspection
All accessories shall be connected with corresponding rated voltage according to the face shield nameplate requirement, and the
following operations should be done:
Electric charging, closing and opening operation, 5times in cycle
Manual charging, closing and opening operation, 5times in cycle
The circuit breaker charging, opening and closing should be normal.
Note: The main circuit must be uncharged. If there is an under-voltage release, the rated voltage must be first connected.
Note: The picture takes NA1-2000X as an example
Summary of Contents for NA1
Page 1: ...Air Circuit Breaker Leading every step reliable new height ...
Page 2: ...Air Circuit Breaker Leading every step reliable new height ...
Page 3: ......
Page 4: ...Page P 001 Page P 039 ACB Air Circuit Breaker NA8G NA1 ...
Page 45: ...P 041 NA1 Air Circuit Breaker 1 3 4 5 7 8 11 12 13 14 15 ...
