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.
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