Specifications for 12 Year HVB Circuit Breaker Maintenance

Per HVB Type B HS145-40kA Breaker Maintenance recommendations are to include but not limited to the following: Replace all sealing rings affected during major maintenance Check SF6 gas pressure Check SF6 gas density monitor settings Full functional testing of pressure switches and 63 relays Compensate Pressure Gauge Compensate Pressure Switch + Regular Pressure Switch Check moisture content of the SF6 gas Leak test fittings and all gas sealing connections Check the anti-pumping circuit, alarms, and lock-outs Perform circuit breaker timing Perform contact resistance (micro-ohms) measurements Check anti-condensation heaters for proper operation Inspect the bushing insulators for cracks Leak check the interphase shaft seals with the breaker in the OPEN and CLOSED positions Check the hardware at the rear tank covers, all flanges, rupture disks, gas plumbing, bellcranks, tank mounting, etc. is tight and secure Remove and inspect arcing contacts Remove and inspect Teflon nozzles and Teflon covers Replace Crankbox O-rings and Dashpot Oil Location: 12-year maintenance shall be performed on the following equipment: Big Pine Substation – 138W1 (SN#H14A2786-201) Big Pine Substation – 138W2 (SN#H14A2786-204) Big Pine Substation – 138W3 (SN#H14A2786-203) Big Coppitt Substation – 138W1 (SN#H145A2786-206) Big Coppitt Substation – 138W2 (SN#H145A2786-205) Big Coppitt Substation – 138W3 (SN#H145A2786-207) US1 Substation - 138W1 (SN#H145A2786-202)

Division 26 -

Electrical.