Electric Motor Control Basics - Book - Page 54
Applying Motor Control in a
Wastewater Application
This article will cover the basic building blocks of pump control. It is not intended to be the
end-all for water and wastewater applications, but rather an introduction.
Introduction
Water and waste water treatment requires moving water through the different stages
of treatment. To do that, pump stations are used. Each part or station of the water
treatment process can require a different type of pump. While the pumps are different,
they all share the common architecture of an electric motor and a method of controlling
those motors.
According to the US EPA, pump station capacities range from 76 lpm (20 gpm) to
more than 378,500 lpm (100,000 gpm). Prefabricated pump stations generally have a
capacity of up to 38,000 lpm (10,000 gpm). Usually, pump stations include at least two
constant-speed pumps ranging in size from 38 to 75,660 lpm (10 to 20,000 gpm) each
and have a basic wet-well level control system to sequence the pumps during normal
operation. Source: EPA 832-F-00-069, September 2000
The process of moving water is extremely energy-intensive. In the US, electric motordriven devices, including pumps, use almost 65%-70% of all electricity produced in the
country. Water and wastewater systems are known to utilize almost 50% of the energy
in any municipality, of which 90% of the energy is used by pumps.
Industrial Control
Basics:
Part 1, Contactors
Industrial Control
Basics: Part 2,
Overload Relays
Industrial Control
Basics: Part 3,
Starters
The Benefits of Type E/F
Motor Protection
Circuit Breakers
Basic Pump Control:
Three Phase DOL Starter
Control of an Electric Pump
Applying Motor Control
in a Wastewater
Application
NEMA vs IEC Motor
Controls
Understanding
IP Ratings
54
