AIR CIRCUIT BREAKERS
www.
sigmaelektrik
.com
18
ACB
SOME TROUBLES AND SOLUTIONS
FACTORY SETTING VALUES
The intelligent controller would be configured as follows, If no special demands was put forward when ordering:
Overload long-delay
Current setting Ir1
In
Delay time setting t1
15S
Short-circuit short-delay
Current setting Ir2
8Ir1
Delay time setting t1
0.4S
12In
Earthed errors
Current setting Ir4
SFA/SDA-2000
SFA/SDA-3200, 4000
SFA/SDA-6300
0.8In or 1200A
(choose smaller-
value)
0.6In or 1600A
(choose smaller-
value)
2000A
Delay time setting t4
OFF
Load monitoring
Monitoring setting C1
In
Monitoring setting ILC2
In
Fault description
Reasons analysis
Maintenance method
Tripping of circuit breaker
Over load tripping (IL indicator flashing)
1. Check the breaking current value and operation
time of intelligent release.
2. Analyze the load and electric network, exclude the
overload if it happens.
3. Match the actual operating current with long time-
delay current setting value.
4. Press the reset button to reclose the breaker
Circuit breaker
1. Check the breaking current value and operation
time of intelligent release.
2. Exclude the short circuit fault if it happens
3. Check the setting value of intelligent release
4. Check the normal state of breaker
5. Press the reset button to reclose the breaker
Earthing fault tripping (IG indicator flashing)
1. Check the breaking current value and acting time of
intelligent release.
2. Exclude the earthing fault if that happens.
3. Match the fault current setting value with the actual
protection.
4. Press the reset button to reclose the breaker.
Under-voltage release fault:
1. Rated working voltage is less than 70%Ue
2. Fault of control unit
1.Check the power is on or not
2.Check the power voltage of under-voltage release, it
shouldn't be less than 85%Ue.
3.Replace the control unit of under-voltage release
Mechanical interlock acting
Check the working state of two circuit breakers fixed
with mechanical interlock
