The new system allows for much better control through modulating the supply valve and better management of scheduling and set-points.
Click here to enlarge image“A system of our size would have never considered ‘buying’ such a full-blown SCADA system not to mention dealing with the hassles of owning and maintaining it,” Heidt said. “H2Ovation provides all of the benefits for a monthly service fee.
“I can now access anything I need to know about my system from anywhere. I can see my tank levels, pump status, change set-points and turn equipment on. I receive and acknowledge alarms. I can do all of this from my office, from home, or once even on a trip to Florida.”
Controlling Flow
Northville’s water rates from the City of Detroit are set based on peak hour/peak day usage. The original float-based control system would open the valve to bring in water to the reservoir tank – often at the most expensive times. Recent years saw rate increases as high as 26 percent.
OHM and HESCO helped implement a new system strategy based on the Healy-Ruff VPAC controller. The new system allows for much better control through modulating the supply valve and better management of scheduling and set-points.
“We went from significant double-digit annual increase to a reduction of over 10% in our rates from the City of Detroit,” Heidt said. “The investment in the control system upgrade has already paid for itself.”
Alarm Monitoring
The original control system also had a traditional “alarm dialer.” A generic “system pump failure” alarm would be sent to the Police Department, which would then contact the Department of Public Works. They would respond to 90 to 100 calls per year from the system – 75% to 90% of which were nuisance or minor alarms that did not require immediate attention or action.
“The system is more reliable and generates a lot fewer ‘nuisance’ alarms. Also, because we can access the system remotely, we can evaluate the problems rather than needing to send someone every time to check things out,” Heidt said. “I’ve only had to send people out to respond to actual events, like to run a generator during an actual power failure.”
When considering wages, overtime, mileage and other cost factors, eliminating 75-90 trips is now saving Northville more than $10,000 annually.
Of course, most problems seem to occur at the most inconvenient times. One important alarm event occurred in the early morning hours on the coldest day of the winter.