The Macedon Substation, which serves areas north of Ft. Recovery and west of Coldwater, has had the following outage dates: 3/14/08, 4/16/09, 4/30/09, and 5/13/09. All four outage dates have resulted in an outage for the entire Macedon Substation.

After each outage, Midwest crews have found on the 12KV substation structure: broken insulators, and insulators with black flash marks on the porcelain. However, there has been no evidence to show what has initiated the outages. On three of the dates, the weather was rainy, however, on 4/16/09 it had rained the day before, but was sunny at the time of the outage.

After each outage, Midwest has replaced the damaged insulators. Midwest has been in contact with the company that manufactures the insulators that have been damaged. They have stated that based upon reviewing pictures of the damaged insulators, the insulators are not failing due to a manufacturing defect. They feel the insulators are operating correctly, and the outage must be due to either contamination on the insulators, or high voltage.

On 5/5/09, we had a contractor clean the Macedon Substation 12KV structure insulators, and treated them with Dow Corning 3099 grease. This was done to remove any contamination that may have been on the insulators. The 5/13/2009 outage would indicate that the outages are not due to contamination of the insulators.

We have been in contact with an engineering consultant to try to determine the cause of the outages. We have exposed the Macedon Substation ground grid and conducted a visual inspection of the Macedon Substation lightning arresters to determine if a bad substation ground grid, or bad lightning arresters may be the cause of the outages. We will test the Macedon Substation ground grid and lightning arresters on 5/21/09. At this time, the Macedon Substation load has been transferred to the Coldwater Metering Point.