Siemens GMSG-GCB Instruction Manual

582.10 The centering ring (28.1) has been looseand floating during installation of thevacuum interrupter. Check that themovable contact is free to movevertically without binding, and thentighten the hardware that secures thecentering ring. Re-check that themovable contact is free to movevertically without binding.2.11 Attach insulating coupler (48.0) andlever (48.6) together, using pin (48.5).Apply retaining clips. Correct pin hasends that have been generouslychamfered.2.12 Open and close circuit breaker severaltimes and then check to see that allbolted joints and devices are tight.3.0 Checking the contact stroke3.1 Open the circuit breaker.3.2 Free insulating coupler (48.0) byremoving pin (48.5). The vacuuminterrupter contacts must now closeautomatically as a consequence ofatmospheric pressure.3.3 Observe the terminal clamp (29.2)through the openings on each side ofthe lower pole support (40.0).Using vernier calipers measure thedistance from the bottom surface of theterminal clamp to the bottom edge ofthe cutout opening. Measure carefullyand record your result.3.4 Connect the insulating coupler (48.0)using pin (48.5) and the retaining clipsprovided.3.5 Repeat the measurement described instep 3.3 again with care to maximizeaccuracy. Record your result.3.6 Determine difference between themeasurements made under steps 3.3and 3.5. Your result should fall withinthe range shown in Table 3: Typicalvacuum interrupter contact life andstroke on page 44.3.7 If you fail to achieve the listed results,carefully repeat the entire proceduremaking certain of your measurements.3.8 Loosen locking nut on eye bolt oninsulated coupler (48.0), and retainposition of the eye. Make adjustments inone-half turn increments. Afteradjustment is completed, tighten eye-bolt locking nut to 26-34 ft-lb(35 to 45 Nm).4.0 After eye bolt is tightened to propertorque, repeat all measurementprocedures, making certain they are inagreement with values indicated in step3.6.5.0 Complete all other maintenanceprocedures. Completely reassembledcircuit breaker should pass high-potentialtest before it is ready for service.Hydraulic shock absorberThe type GMSG mechanism is equipped withhydraulic shock-absorber and a stop bar thatfunctions when the circuit breaker opens(refer to Figure 15: Stored-energy operatingmechanism on page 20). The shock absorber(61.8) should require no adjustment.However, at maintenance checks, the shockabsorber should be examined for evidence ofleaking. If evidence of fluid leakage is found,the shock absorber must be replaced toprevent damage to the vacuum-interrupterbellows.