ABB SF6 LTB 245E1 BLG 1002A Product Manual page 119

Operating Mechanism Maintenance
4.9.1 Closing dashpot
B20015
4.9.2 Opening dashpot
Wrong
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1HSB515409-100 en rev2
Check the oil level in the dashpot by recording the damping effect during operation.
• Connect the circuit-breaker analyser's sensor to the cam shaft in the operating
mechanism and record a damping curve. Check the damping distance and the
damping time as set out in
are outside the specified values, replace the complete dashpot.
Figure 4-11. Damping curve, Closing dashpot.
Check the oil level in the dashpot by recording the damping effect during operation.
• Connect the circuit-breaker analyser's sensor to the breaker's shaft and record a
damping curve. Check the damping distance and the damping time as set out in
Figure 4-12. If the recorded curve differs from the correct curve, replace the
complete dashpot.
Figure 4-12. Damping curves, Opening dashpot.
Figure 4-11. If the measured values for "a" and "b"
"b"
"a" = damping distance 15-25 mm
"b" = damping time 80-300 ms
Right Wrong
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