Over a period of time the chain will corrode,stiffen,seize,then break. The closing spring will not be charged. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system stability. The spring charging motor will continue to run.Troubleshoot up to 2 hours, repair up to 2 days, 2people, $2000. This has occurred in the past elsewhere but the actual frequency has not been documented.

Over a period of time the chain will corrode,stiffen,seize,then break.The closing spring will not be charged. Breaker will trip but will not re-close.Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system stability. Troubleshoot up to 2 hours, repair up to 4 days, 2people, $4000. This has occurred in the past elsewhere but the actual frequency has not been documented.This could result in secondary damage to the operating mechanism components.

Over a period of time the springs will corrode,weaken, break this could jam the operating mechanism. Breaker will trip but will not re-close.Therefore the breaker is unable to switch closed.This will increase the risk of customer outage/system stability.Troubleshoot up to 2 hours, repair up to 4 days, 2 people, $4000. The actual frequency has not been documented.This could result in secondary damage to the operating mechanism components.

The clutch will slip excessively, not turning the gear, does not drive the chain, closing springs are not being charged.Breaker will trip but will not re-close.Therefore the breaker is unable to switch closed.This will increase the risk of customer outage/system instability.This could cause the motor to trip out on thermal overload. Troubleshoot up to 2 hrs,clean and readjust clutch up to 4 hrs, 2 people, $600 total.This has occurred in the past but the actual frequency has not been documented.

Over a period of time the clutch springs will weaken, less force on the clutch, increasing wear, The clutch will slip excessively, not turning the gear, does not drive the chain, closing springs are not being charged. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. This could cause the motor to trip out on thermal overload. Troubleshoot up to 2 hrs,repair up to 7 hrs, 2 people, $900 total. The actual failure frequency has not been documented.

Over a period of time excessive grease will be vaporized , the clutch will slip excessively due to an oil film on the clutch plates, not turning the gear, does not drive the chain, closing springs are not being charged. Breaker will trip but will not reclose. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. This could cause the motor to trip out on thermal overload. Troubleshoot up to 2 hrs, repair up to 4 hrs, 2 people, $600 total. The actual failure frequency has not been documented.

Over a period of time the wear will increase, resulting in noise,heat,and seizure. Closing springs are not being charged. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. This could cause the motor to trip out on thermal overload. Troubleshoot up to 2 hrs,repair up to 4days to rebuild the gearbox arrangement, 2 people, $4000 total plus parts. The actual failure frequency has not been documented.

Over a period of time the brushes become thinner, causing excessive arcing, carbon buildup, resistance builds and the motor does not start. Closing springs are not being charged. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. Troubleshoot up to 2 hrs, repair up to 4 hrs to replace the motor brushes, 2 people, $600 total. The actual failure frequency has not been documented.

The motor does not start. Closing springs are not being charged. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. Troubleshoot up to 2 hrs, repair up to 4 hrs to replace the motor, 2 people, $600 total. The actual failure frequency has not been documented.

The motor does not start. Closing springs are not being charged. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. Troubleshoot up to 2 hrs, repair up to 4 hrs, 2 people, $600 total. This has occurred in the past but the actual frequency has not been documented.

To Be Analysed Separately - prevents breaker from opening and closing

Over a period of time the main closing latch wears, the latch end becomes rounded and fails to latch the closing spring bridge. ( details on the evidence and consequences of failure needs to be determined).

The connecting pin will fall out. The closing and opening operation would not be transferred from the operating mechanism to the pole peices. The breaker will not open or close. Unable to switch (open/close) the transmission line (2.82L) at all. This will increase the risk of customer outage/system instability. The cabinet mechanism would operate under a no mechanical load condition. This could cause secondary damage to the control cabinet operating mechanism. Troubleshoot up to 2 hrs,repair up to 4 days to replace the control cabinet and then repair the damaged cabinet, 2 people, $4000 total plus parts. The actual failure frequency has not been documented.

Over a period of time the epoxy connection between the cap and the porcelin will deteriorate to the point where the stack will not rotate. The interrupter does not operate.The breaker will not open or close. The breaker will not be able to trip under fault conditions. This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This could also cause increased customer outage and system stability. Potential for increase secondary damage at fault location. This will increase the risk of customer outage/system instability. Troubleshoot up to 2 hours, repair up to 7 hrs to replace the stack, 2 people, $1000 plus parts. The actual frequency has not been documented.

Over a period of time the wear will increase, result in noise,heat AND seizing. This will result in slowing the breaker operation (open/close) until the stack will not rotate. This could result in damaging the operating stack.The interrupter does not operate. The breaker will not open or close. The breaker will not be able to trip under fault conditions. This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This could also cause increased customer outage and system instability. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hours, repair up to 2 days to replace the bearing and repair any secondary damage , 2 people, $2000 plus parts. The actual frequency has not been documented.

Over a period of time pin will corrode and then seize causing the linkage to break. The interrupter does not operate. The breaker will not open or close. The breaker will not be able to trip under fault conditions. This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This could also cause increased customer outage and system instability. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hours, repair up to 7 hrs to replace the pin and repair any secondary damage , 2 people, $1000 plus parts. The actual frequency has not been documented.

The interrupting chamber will not operate. The breaker will not open or close. The breaker will not be able to trip under fault conditions. This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutes. Potential for increase secondary damage at fault location. Troubleshoot up to 4 hours, repair up to 4 days to replace the interrupting chamber and rebuild the rectalinear motion mechanism, 2 people, $4000 plus parts. The actual frequency has not been documented.

Over a period of time the contacts will burn and contact resistance will increase due to arcing and become shorter and thinner. Increased arcing, heat, gases will be gererated, contaminating the insulating oil. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

The breaker mechanism will indicate close, but will not complete the circuit. Unable to switch (open/close) the transmission line (2.82L) at all. This will increase the risk of customer outage/system instability. Troubleshoot and repair up to 4 hrs to install the female contact , 2 people, $400. The actual frequency has not been documented.

Over a period of time this would cause increase drag ,increased current draw on the motor, and thermal overload trip on the motor. The breaker will not close due to the closing springs not being charged. This will increase the risk of customer outage/system instability. Troubleshoot and repair up to 3 hrs. Total $300.

Over a period of time discs, ( measurement S), diameter will increase to greater than 30.5 mm. It reduces the arc exstinguishing capability. The breaker goes open, but fails to exstinguish the arc, increasing arcing,heat and gases will be generated, contaminating the insulating oil. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis, and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Over a period of time the carbon will buildup in the insulating chamber. This reduces the dielectric strength of the insulating oil, and the oil fails to insulate. This could cause the oil to expand suddenly, resulting in an explosion. This would cause significant secondary damage which would prevent switching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil, severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to repair. Possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Over a period of time the main opening latch wears, the latch end becomes rounded and fails to latch breaker mechanism in the closed position. The opening spring will open the breaker mechanism causing the closing springs to be recharged. Resulting in a breaker trip free. Breaker will trip but will not re-close. Therefore the breaker is unable to switch closed. This will increase the risk of customer outage/system instability. Troubleshoot up to 2 hrs, repair up to 7 hrs to replace the main opening latch, 2 people, $1000 total. The actual failure frequency has not been documented.

Over a period of time the contact roller springs will fatigue resulting in loss of roller tension. This will lead to increased burning and roller contact resistance will increase due to arcing. Increased arcing, heat, gases will be generated, contaminating the insulating oil. This leads to breakdown of the insulating oil dielectric. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

To Be Analyzed Separately

To Be Analyzed Separately - preventing breaker from opening

Over a period of time the clips will weaken, allowing the fuse to loosen and break contact of the circuit. The breaker will not be able to trip under fault conditions. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutes. This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and repair up to 2 hrs to repair, total cost of $400 plus parts.

Over a period of time the fuse element will weaken and open.The breaker will not be able to trip under fault conditions. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutes This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and may require up to 2 hrs to repair, total cost of $400 plus parts. This has occured but there has been no actual frequency determined for this failure mode.

Over a period of time the vibration will cause the connections to loosen and lose contact.The breaker will not be able to trip under fault conditions. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutes This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and may require up to 2 hrs to repair, total cost of $400 plus parts. No failure frequency has been documented.

Coil will open and cause the circuit to open.The breaker will not be able to trip under fault conditions. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutes This could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and repair up to 4 hrs to replace coil , total cost of $600 plus parts.

Over a period of time the spring will corrode, weaken and break. Breaker will not open. Cannot open the transmission line (2.82L). Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line.This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutes. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs, repair (replace opening spring) up to 2 days, 2 people $2000 total plus parts. The actual failure frequency has not been documented.

This could allow personnel to come in direct contact with moving equipment. This could lead to possible injury for personnel working in the area. Contaminates will enter the control cabinet. Over a period of time this may cause control circuit failures and may lead to corrosion of mechanical components. This could prevent the breaker from opening or closing. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line.This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minutesThis could also cause false operation.Troubleshoot minimal, repair time to replace cabinet up to 4 days, $4000 total. This failure frequency has not been documented.

Over a period of time the gasket will deteriate. It will show signs of deterioration, breakage and bad gasket syndrom. Contaminates will enter the control cabinet. This may cause control circuit failures and may lead to corrosion of mechanical components. This could prevent the breaker from opening or closing. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line.This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute This could also cause false operation.Troubleshoot minimal, repair time to replace cabinet up to 4 days, $4000 total. This failure has occured but the frequency of failure has not been documented.

Heater does not come on during very cold conditions. Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and repair up to 2 hrs to repair, total cost of $400 plus parts. This failure has occured but the frequency rate has not been documented.

Heater does not come on at temperatures below 10 Deg C. Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close.Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line.This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and may require up to 2 hrs to repair, total cost of $400 plus parts. This failure has occured but no failure frequency has been documented.

Heater does not come on during very cold conditions.Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close. The breaker will not be able to trip under fault conditions. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and may require up to 2 hrs to repair, total cost of $400 plus parts.

To Be Analyzed Separately

Over a period of time the clips will weaken, allowing the fuse to loosen and break contact of the heater circuit. Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close. The breaker will not be able to trip under fault conditions. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Troubleshoot up to 2 hrs and repair up to 2 hrs to replace the fuse holder and fuse, total cost of $400 plus parts.

Over a period of time the fuse element will weaken and break contact of the AC circuit. Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close. The breaker will not be able to trip under fault conditions. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Troubleshoot up to 2 hrs and repair up to 2 hrs to replace the fuse holder and fuse, total cost of $400 plus parts.This failure frequency has not been documented.

Both heaters does not come on during very cold conditions. Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. Condensation will appear at any temperature resulting in the control cabinet components corroding. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close. The breaker will not be able to trip under fault conditions. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and may require up to 2 hrs to repair, total cost of $400. This failure has occured but no frequency has been documented.

Heater does not come on during very cold conditions. Over a period of time the mechanical operating mechanism will not move as freely due to grease gelling. Condensation will appear at any temperature resulting in the control cabinet components corroding. This results in the electical components operating at a higher current level. This increases the risk of the electrical components burning out thus causing the breaker not to open or close. The breaker will not be able to trip under fault conditions. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Potential for increase secondary damage at fault location. Troubleshoot up to 2 hrs and may require up to 2 hrs to repair, total cost of $400. This failure frequency has not been documented.

Over a period of time condensation will accumulate inside control cabinet when the ambient temperature is above 10 Deg C. The control cabinet components will corrode. This will result in corrosion of both the mechanical and electrical components. The breaker will not to open or close. The breaker will not be able to trip under fault conditions. Under fault this could result in increased risk to public/personnel being electrocuted due to delayed clearing of transmission line. This will also cause increased customer outage and system instability due to the fault having to be cleared by the other 138kV breakers via protection devices. This will result in a complete outage of the 138kV Bus at 02 Sub and considerable customer outage minute. Potential for increased secondary damage at fault location. Troubleshoot up to 2 hrs and repair up to 4 days to replace the cabinet and to repair the damaged cabinet, total cost of $4000 plus parts. The failure frequency has not been documented.

Unable to operate the breaker electrically from the desired location. If the switch is not in the remote position, but the desire is to operate it remotely this would delay the closing of the breaker.This would increase the risk of system instability. Troubleshoot up to 2 hrs. This failure function frequency has not been documented.

Unable to operate the breaker electrically from the desired location. If the switch is not in the remote position, but the desire is to operate it remotely this would delay the closing of the breaker.This would increase the risk of system instability. If the disconnect position was selected but not made this could result in personnel being injured by receiving an electrical shock or coming in contact with moving equipment. TS and repair up to 4 hrs plus parts cost, total $400. There is no failure frequency documented for this failure mode.

Loss of local electrical control of the breaker. Could lead to longer maintenance downtime. Troubleshoot and repair up to 2 hrs. Total cost $200 plus parts.

When the button is pushed the close or open linkage will not collapse. The control panel door would have to opened and a alternate method would have to be used to collapse the open linkage. Troubleshoot up to 1 hr to adjust the linkage.

This Only Matters If there is a loss of electrical opening capability and mechanical trip mechanism fails. The control panel door would have tobe opened and an alternate method would have to be used to collapse the open linkage. Troubleshoot and repair up to 2 hrs for the mechanical trip mechanism..

Would not be able to slowly close the breaker manually. This would have minimal impact because other closing tools are available on site or at another site.

Would not be able to slowly open the breaker manually. This could have minimal impact on delaying maintenance. Repair up to 1 hr.

If the switch fails closed the isolation would have to be done further back in the circuit. Minimal impact. If the switch fails open the breaker will not be able to close due to springs not being charged. Increased customer outage and system stability. Troubleshoot and repair up to 1 hr.

If the switch fails closed the isolation would have to be done further back in the circuit. Minimal impact. If the switch fails open the breaker will not be able to operate.Increased customer outage and system stability. Troubleshoot and repair up to 1 hr.

Would not be able to count the number of breaker cycles (open/close). Unable to track the condition, based on the number of counts. It is unlikely that the time between maintenance could be falsely extended because the time based approach will be used to determine the required maintenance schedule. Troubleshoot and repair up to 1 hr. Total $100 plus parts.

The poles will not open simultaneously which will could create an excessive load interrupting on the last pole, which will cause excessive wear on the contacts. (Under normal switching could cause a protective relay operation due to inbalance current?) Could increase the risk of customer outage and system instabilty. The poles does not close simultaneously could cause the first pole in which is the last pole out which will could create an excessive load interrupting on the last pole, which will cause excessive wear on the contacts. Troubleshoot up to 4 hrs and repair up to 5 hrs to adjust the interface linkage. Total up to $1000. Failure frequency has not been documented.

Over a period of time the contacts will wear, decreasing the contact wipe, increasing the possiblity of none simultaneous opening.The poles will not open simultaneously which will could create an excessive load interrupting on the last pole, which will cause excessive wear on the contacts. Under normal switching could have a protective relay operation due to inbalance current. Could increase the risk of customer outage and system instabilty. Troubleshoot up to 4 hrs and repair up to 5 hrs to adjust the interface linkage. Total up to $1000 plus parts. Failure frequency has not been documented.

Over a period of time the nuts will loosen and the linkage rotate out of adjustement.he poles will not open simultaneously which will could create an excessive load interrupting on the last pole, which will cause excessive wear on the contacts. Under normal switching could have a protective relay operation due to inbalance current. Could increase the risk of customer outage and system instabilty. Troubleshoot up to 4 hrs and repair up to 5 hrs to adjust the interface linkage. Total up to $1000. Failure frequency has not been documented.

OAPOT the spring will weaken causing the opening time to increase to greater than 39ms. This could cause excessive arcing , gases,oil contamination, explosion, secondary damage,(same as 1-A-20) increased customer outage and system stability due to second line of protection having to operate. Troubleshoot and repair up to 3 weeks (same as 1-A- 20)

The spring could be adjusted to a time of greater than 39 ms.This could cause excessive arcing , gases,oil contamination, explosion, secondary damage,(same as 1-A- 20) increased customer outage and system stability due to second line of protection having to operate. Troubleshoot and repair up to 3 weeks (same as 1-A-20). The spring could be adjusted to a time less then 29 ms. Causing excessive load on the dampening piston, lead to failure of the dampening piston assembly. This could lead to secondary damage of the interrupting chamber. TS up to 2 hrs, repair time up to 1 week to replace the breaker pole. Total $5000 plus parts.

Over a period of time the opening spring nuts will loosen and causing the time to be greater than 39 ms.This could cause excessive arcing , gases,oil contamination, explosion, secondary damage,(same as 1-A-20) increased customer outage and system stability due to second line of protection having to operate. Troubleshoot and repair up to 3 weeks (same as 1-A-20).

Over a period of time the linkage will corrode and bind causing the opening time to increase to greater than 39ms. This could cause excessive arcing , gases,oil contamination, explosion, secondary damage,(same as 1-A-20) increased customer outage and system stability due to second line of protection having to operate. Troubleshoot and repair up to 3 weeks (same as 1-A-20)

Over a period of time the pins will corrode, bind, and breaker closing time will exceed 130 ms.This will cause the main contacts to arc longer, causing premature wear. Leads to increased contamination of the oil. Over a period of time the breaker contacts will burn off resulting the breaker not closing at all. Increase the risk of customer outage and system stability. ( same as 1-A-20).

Contaminates will enter the operating tube and the control cabinet. This will result in corrosion, binding, and breaker operating time will exceed opening and closing time specs.This will cause the main contacts to arc longer, causing premature wear. Leads to increased contamination of the oil. Over a period of time the breaker contacts will burn off resulting the breaker not closing at all. Increase the risk of customer outage and system stability. ( same as 1-A-20).

Personnel in the area could come in contact with the moving spring resulting in injury. Troubleshoot and repair to replace the cover

Over a period of time contaminants will cause a loss of the electrical insulating properties. This will result in a flashover on the insulator, resulting in a bus differential protection operation.This will result in losing the 138 kV bus.This could result in the insulator exploding and leading to injury for publi/personnel in the area. This could cause significant secondary damage to adjacent equipment. This will result in a total substation outage, significant customer outage and risk to increased system instability. This could result in replacement of the flashed over insulator or entire breaker.Troubleshoot and repair up to 3 weeks, total $250,000.

Insulator skirts would become chiped or broken. This exposes the poros material underneath the glaze and the moisture will ingress into the insulator. Will cause a loss of the electrical insulating properties. This will result in a flashover on the insulator, resulting in a bus differential protection operation.This will result in losing the 138 kV bus.This could result in the insulator exploding and leading to injury for publi/personnel in the area. This could cause significant secondary damage to adjacent equipment. This will result in a total substation outage, significant customer outage and risk to increased system instability. This could result in replacement of the flashed over insulator or entire breaker.Troubleshoot and repair up to 3 weeks, total $250,000.

Over a period of time the insulator may crack, This exposes the poros material underneath the glaze and the moisture will ingress into the insulator. Will cause a loss of the electrical insulating properties. This will result in a flashover on the insulator, resulting in a bus differential protection operation.This will result in losing the 138 kV bus.This could result in the insulator exploding and leading to injury for publi/personnel in the area. This could cause significant secondary damage to adjacent equipment. This will result in a total substation outage, significant customer outage and risk to increased system instability. This could result in replacement of the flashed over insulator or entire breaker.Troubleshoot and repair up to 3 weeks, total $250,000.

There will be a void in the porcelin. This void would weaken the porcelin and lead to a crack.This exposes the poros material underneath the glaze and the moisture will ingress into the insulator. Will cause a loss of the electrical insulating properties. This will result in a flashover on the insulator, resulting in a bus differential protection operation.This will result in losing the 138 kV bus.This could result in the insulator exploding and leading to injury for public/personnel in the area. This could cause significant secondary damage to adjacent equipment. This will result in a total substation outage, significant customer outage and risk to increased system instability. This could result in replacement of the flashed over insulator or entire breaker.Troubleshoot and repair up to 3 weeks, total $250,000.

No Dominant Failure Mode

Over a period of time the drain valve packing hardens and cracks. The pressure in the interrupting chamber forces oil out through the failed packing. This would result in an environmental oil release incident. This would lead to enough loss of insulating oil to lose it's interrupting properties. The breaker goes open, but fails to exstinguish the arc, increasing arcing,heat and gases will be generated, contaminating the insulating oil. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis, and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

The pressure in the interrupting chamber forces oil out through the lose valve connection. This would result in an environmental oil release incident. This would lead to enough loss of insulating oil to lose it's interrupting properties. During an open or close operation this will result in an explosion. The breaker goes open, but fails to exstinguish the arc, increasing arcing,heat and gases will be generated, contaminating the insulating oil. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis, and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

The pressure in the interrupting chamber forces oil out through the seal. This would result in an environmental oil release incident. This would lead to enough loss of insulating oil to lose it's interrupting properties. During an open or close operation this will result in an explosion.The breaker goes open, but fails to exstinguish the arc, increasing arcing,heat and gases will be generated, contaminating the insulating oil. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis, and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Loss of nitrogen. This will be indicated on local nitrogen pressure gauge. ( function of nitrogen to be determined). If the nitrogen pressure drops to 1 bar this will allow contamiantes to enter the oil Over a period of time this reduces the dielectric strength of the insulating oil, oil fails to insulate.This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality.This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system stability.Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis and possible an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Loss of nitrogen. This will be indicated on local nitrogen pressure gauge. ( function of nitrogen to be determined) This reduces the dielectric strength of the insulating oil, oil fails to insulate.This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality.This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system stability.Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis and possible an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Loss of nitrogen. This will be indicated on local nitrogen pressure gauge. ( function of nitrogen to be determined)This reduces the dielectric strength of the insulating oil, oil fails to insulate.This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality.This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system stability.Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis and possible an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Loss of nitrogen. This will be indicated on local nitrogen pressure gauge. ( function of nitrogen to be determined)This reduces the dielectric strength of the insulating oil, oil fails to insulate.This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all. This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality.This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system stability.Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis and possible an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.

Pressure increases in the interrupting chamber above 0.7 mpa. And the blow off valve does not open, causing increased stress on the interrupting chamber seals. This would weaken the seals and would ultimately result in a leak of oil and or gas.This would result in an environmental oil release incident. This would lead to enough loss of insulating oil to lose it's interrupting properties. The breaker goes open, but fails to exstinguish the arc, increasing arcing,heat and gases will be generated, contaminating the insulating oil. This could cause the oil to expand suddenly resulting in an explosion. This would cause significant secondary damage which would prevent swiching at all This could result in public/personnel in the area being hit by flying debris, resulting in injury or fatality. This could result in an environmental release of insulating oil and could result in severe secondary damage and customer outage and system instability. Troubleshoot and repair time up to 3 weeks to replace the breaker and carry out root cause failure analysis, and possibly an additional week to repair secondary damage to equipment outside of this analysis. Total financial impact could be $250,000.