How Indianapolis P&L Fights Steam Threats on Underground Distribution

From 2010 to 2015, Indianapolis Power & Light experienced an increase in secondary network events, resulting in cable fires and dislodged manhole covers. One of the main causes was long-term exposure to excessive heat from the steam distribution system.

The steam infrastructure in downtown Indianapolis is often located near IPL’s underground infrastructure and power cables.The corrosive nature of steam prematurely ages cable and degrades the outer jacket. In addition, steam can deform conduit if it is exposed long enough to the leaks.

Traditionally, steam leaks in Indianapolis were identified by the steam company during its annual thermal survey, in which a thermal scan for hot spots was conducted on the downtown streets. Additionally, IPL crews would report any heat issues encountered during routine inspections. Between IPL’s inspections and the steam company’s thermal scans, heat issues could go undetected for a year or more. It was not enough.

So the IPL engineering team needed to devise a more sophisticated solution to actively monitor the utility’s infrastructure in real time. The following images give you an insight into how they did it. These images originally appeared in the February 2018 issue of T&D World. For the full article, see "Cable Monitoring All Steamed Up."