Remote status monitoring of lift stations can be provided at a lower cost than SCADA systems, resulting in a much shorter period for realizing full return on investment.
This type of monitoring system, offered by ABB Inc., features very low capital costs, and consists of equipment that is simple to install and very cost effective to operate and maintain. The only equipment components are located at each lift station:
- One current sensor for each lift pump motor and, if applicable, one for the sump pump motor.
- One small, wall-mounted electronic node box for accepting the above motor current signals and discrete signals from intrusion-type alarms and high well level alarms.
This node box at each lift station on a periodic basis (or when alarms occur) sends collected data to ABB's redundant and geographically separated Database Servers using only a local phone call via the utility's normal Internet Service Provider. The additional capital and ongoing maintenance cost of a separate SCADA telemetry system is consequently eliminated. In most cases, the existing phone line to the lift station is used for this purpose, or a new phone line or cell phone modem can be installed if needed.
The Database Servers store and analyze the received data, and provide easily readable displays containing current and historical information at the Server website. The screen captures shown at right are samples of these displays, with additional information and demos available at www.abb.com/lift-station. Using only this motor current data plus plant information provided by the utility, these displays are configured by ABB to provide derived information.
For example this website contains conclusions regarding pump run frequency and duration, pump motor current usage, lift station inflow and pump flow output for constant speed pumps, sump pump motor activation, and alarms regarding lift station problems.
For a small subscription fee, password-authorized utility personnel can access this website from different locations over a secure, encrypted Internet channel using a local phone call to the utility's normal Internet Service Provider. The staff can use their own personal computers for this purpose, thereby eliminating the additional capital cost and ongoing maintenance cost of separate console equipment and software. Lift station alarms also can be sent to designated utility personnel via text pagers or through email.
Consequently many of the benefits of a full-blown SCADA system are provided at a fraction of the capital cost (and at a fraction of the ongoing maintenance cost as well). While continuous data updates from the lift station (e.g., as to which pump is currently operating) may be interesting, the benefits of a continuous connection often do not outweigh the costs. The benefits provided by ABB's offering include:
- Less liability to the utility (relating to wastewater leakage/flooding);
- Smaller equipment repair costs due to early detection and automated diagnosis/warning of pump equipment and lift station problems;
- More effective use of utility personnel through reduced frequencies of inspection and maintenance visits to remote lift stations;
- Less liability to the utility and less risk to utility personnel by reducing the frequency of entry into hazardous, confined spaces;
- Data stored indefinitely at the Database Server locations for use by the utility at a later date;
- Availability of historical data that assists strategic planning of upgrades to lift station equipment and capacity;
- Minimal capital and ongoing maintenance costs, both for telemetry equipment and for the SCADA system equipment.
Perhaps most importantly, ABB continues to support the utility in its ongoing needs regarding lift station operation.