Map Tree Trim Year Grosse Pointe Sub: 2011 Average Last Pole top - PowerPoint PPT Presentation

City of Grosse Pointe Woods • # of Residents: 17,000 + • # of Circuits: 16 • # of General Purpose Substations Feeding Grosse Pointe Woods Area: 2 • Total Peak Load Served: 35 MVA • Next Tree Trim Year Vernier Sub: 2013 Map • Tree Trim Year Grosse Pointe Sub: 2011 • Average Last Pole top Maintenance (PTM) Year: 2007 1

2 Distribution Circuit

Distribution Circuit 1481 Vernier Outages July 6 (11:59) through July 8 (21:35) • – July 6: No crews available due to the ongoing catastrophic storm. – July 7: Crew Dispatched at 7:03 • Tree trim performed near Marter and Alger. • Replaced wire that came down. • Attempted to close the breaker and the breaker didn’t hold. • Patrolled the circuit. • 21:24 halted operations. – July 8: Crew Dispatched at 7:19 • Attempt to close the breaker and the breaker didn’t hold. • Patrolled the circuit again. • Started putting back small sections of the circuit at a time. • Breaker held and restored all customers at 21:35. Vernier Substation 3

Distribution Circuit 1481 Vernier Outages • August 29 (12:56) through (20:00) – August 29: Crew Dispatched at 13:12 • Reason: DTE Contract tree trim crew working at a hazardous tree site near Hampton and Charlevoix. A rotted out limb came down on the wires and caused outage. • The branch was removed 14:38. • Attempt to close the breaker and the breaker didn’t hold. • Misoperation on reclosing relay suspected. Fuse • Started putting back small sections of the circuit at a time. • Breaker held and restored all customers at 20:00. Vernier Substation 4

Distribution Circuit 1481 Vernier Outages August 29 – What should have happened. – Reason: DTE Contract tree trim crew working at a hazardous tree site near Hampton and Charlevoix. A rotted out limb came down on the wires and caused outage. – The relaying at Vernier Substation opens the breaker. – The fuse on Goethe, south of Hampton blows. – In less than a second the reclosing relay should sense that the fault has been Fuse cleared and closes the breaker. – The outage should be contained to the residents located on the south side of Hampton and on north side of Hollywood between Goethe and Charlevoix until 14:38 by installing a new fuse. Vernier Substation 5

Short Term Countermeasures for DC 1481 Vernier Action: Replace Reclosing relay at Vernier Substation and inspect the breaker. Results: • Relay Replacement & inspection completed on August 31, 2012 Action: Review Relaying scheme for DC 1481 Vernier Results: • Relaying scheme review was completed on September 5, 2012 Action: Perform pole by pole circuit patrol on DC 1481 Vernier Results: • Patrol completed August 12, 2012 • No Immediate line or pole top maintenance problems were found. However, a hazardous tree location was discovered near Hampton and Charleviox. Action: Perform a infrared survey of DC 1481 Vernier Results: • See next slide. 6

Infrared Results: • Summary of Hot Spots: – Fuses: 4 – Transformer Connections: 1 – Total number of Hot spots: 5 • Three Locations: – 1334 Anita – 1383 Anita – 1828 Anita 7

Longer Term Countermeasures for Grosse Pointe Woods • A 30+ person committee is working on a long term Reliability Plan of all the Grosse Pointes. – DTE Energy has begun a cross functional analysis to identify any potential unforeseen issues that would affect the reliability in the greater Grosse Pointe community. • Perform relay studies on all circuits in Grosse Pointe Woods by the end of 2012. • Fix Trunk line issues discovered during manhole inspections by the end of 2013. • Have Breaker inspections performed on breakers at Vernier and Grosse Pointe substations by the end of 2013. • Two large projects to split circuits. 8

Splitting of DC 1481 Vernier New Circuit Vernier Substation Work to be done: • Install new breaker at Vernier Substation. • Install 1,100 feet of underground cable. • Install 100 feet of conduit. 9 • Reconductor 3,100 feet of overhead wire.

Splitting of DC 1130 Grosse Pointe New Senior Living New Complex Circuit Cook Cook Country Club of Detroit Country Club of Detroit Moross Moross Grosse Pointe Substation Work to be done: • Use an existing breaker at Grosse Pointe Substation. • Install 1,100 feet of underground cable. • Install 900 feet of conduit. • Reconductor 3,800 feet of overhead wire. 10