Commerce Township WWTP

Commerce Township's Wastewater Treatment Plant processes more than 2 million gallons of wastewater per day for its Michigan community — a volume that demands continuous, reliable operation. Following a major 2010 expansion that nearly tripled capacity from 2.4 to 8.5 million gallons per day, the facility installed variable frequency drives (VFDs) to support the upgraded infrastructure. These VFDs immediately began experiencing frequent power interruptions, forcing staff to manually reset process equipment on a recurring basis. Over time, cumulative voltage disturbances damaged two VFDs outright and caused multiple hours of unplanned downtime. Without visibility into incoming power quality, operators could only respond to failures rather than prevent them — creating compliance exposure and mounting equipment replacement costs.

Rockwell Automation's Global Solutions team — who had originally installed the VFDs — deployed the Allen-Bradley Bulletin 1608 i-Sense voltage monitor, an IoT-connected sensor platform that continuously collects, analyzes, and pushes real-time notifications about incoming power quality events. The monitor integrates with existing infrastructure via IP address or analog phone line and feeds data into a hosted web portal, while also correlating readings with other i-Sense units in the region to contextualize disturbances. Alongside the hardware deployment, Rockwell Automation conducted a formal power quality study that cross-referenced voltage event logs with VFD trip records — confirming overvoltage as the root cause. The study also revealed that the facility's generator shutdown and restart practices were accelerating VFD wear, and that only one transient surge suppressor was installed where multiple were required. The monitor supplemented the plant's existing SCADA system, providing event alerts even when SCADA was offline.

Within months of deployment, Commerce Township WWTP identified and documented the root causes behind its recurring VFD failures — information the facility used directly in negotiations with its power provider to remediate systemic grid-side issues. Key outcomes included:

• Compliance risk reduced: Real-time alerts enabled operators to respond to power events before they escalated to reportable compliance failures
• Downtime avoided: When a major power event tripped 95% of plant equipment while SCADA was offline, the i-Sense monitor independently notified plant management — enabling rapid operator response that prevented extended service disruption
• Infrastructure hardened: The power quality study prompted installation of additional transient surge suppressors, reducing future exposure to voltage spikes
• VFD lifecycle extended: Revised generator cycling practices, informed by monitoring data, reduced cumulative stress on drive hardware

• Power utilities measure availability, not quality — facilities running sensitive automation equipment should not assume clean power without independent verification
• IoT-based power quality monitors can serve as a redundant notification layer when primary SCADA systems are unavailable, closing a critical alerting gap
• A formal power quality study provides the documented evidence needed to engage power providers in root cause remediation — anecdotal complaints rarely move the needle
• Expansion projects that add VFDs or other power-sensitive automation should include power quality baseline assessment as part of commissioning, not as a reactive measure after failures occur
• Generator management practices are a frequently overlooked source of VFD degradation; controlled power cycling protocols should be validated against manufacturer specifications