The team decided to implement the Allen-Bradley® Bulletin 1608™ i-Sense® voltage monitor to collect, analyze and notify subscribers of incoming power quality. The monitor can interface with the Internet of Things in several ways with an analog phone line, or connect to the existing IT infrastructor with a IP address. Yet, in some highly secure environments, choosing to not connect to the local IT environment may be a preferred approach. Once the data is collected, it is hosted in a web portal for customer use and is also integrated with other i-Sense monitors in the area to better understand regional power disturbances.
“The installation of the i-Sense voltage monitor allowed us to focus on specific periods of internal data and identify where the main problems were occurring,” Bennett said. “As a result, we were able to pinpoint the issues as they related to our incoming power.”
Once the voltage monitoring solution was installed, the WRC also moved forward with a power quality study to better identify and document issues throughout the plant. The results allowed the Rockwell Automation team to confirm that voltage disturbances took place the same time the VFDs were tripped on overvoltage when running.
The monitor also alerted the facility about their generator power events. Fast generator shutdown and restart practices can impact the long-term durability of the drives. Controlled power cycling of VFDs should be managed in a methodical manner. For that reason, the Commerce Township WWTP was advised of practices that were shortening the life cycles of its VFDs.
It Made Sense
Within months of monitoring incoming power, Commerce Township was finally able to determine the root cause of its failed VFDs.
“There were two reasons why we installed the i-Sense voltage monitor,” said Greg Knauf, superintendent of the Commerce Township WWTP. “One reason was due to our consistent power interruptions and the other was a result of the two damaged VFDs. The data provided us documentation to go back to our power provider with results and work with them on addressing the power quality issues.”
While the Commerce Township WWTP now has data to work with its power provider on quality interruptions, the plant has also gained a sense of reliability since its implementation. Just a month after the product was installed, Knauf received an email from the monitor that indicated the WWTP experienced a power event. The WWTP’s SCADA system did not send out notification to Safety Dispatch due to the SCADA system being down.
“The moment I arrived home, I checked my laptop due to my concern of the WWTP’s equipment. Sure enough, 95 percent of the WWTP’s equipment was tripped,” Knauf said
As a result, Knauf was able to call an operator to restart equipment and get the plant up and running. If the power event would have gone unnoticed, this could have greatly impacted the operation of the WWTP and compliance could have been effected.
