When a major animal feed
manufacturer, producing
over 34,000t of product
every year from its Merseyside plant
wanted to explore energy saving
opportunities it contacted Rewinds &
J.Windsor, an Official Drives Partner
for Control Techniques inverters.

Electricity consumption at the
Merseyside plant was close to
£94,000 per year and with prices
rising, the company tasked RJW with
a site-wide, energy reduction survey.

This identified 12 motors and
motor/fan units as offering the
greatest potential payback, according
to cost analysis software specially
written by Control Techniques.
Twelve drive panels containing
‘Commander SK’ inverters were built
at RJW’s panel building department
and installed by the company’s site
installation team. The drives varied in
size from 5.5 to 37kW with an average
size of 15kW.

The company says by using inverter
drives, it was possible to reduce the
speed of the motors running the fans
and therefore save the energy used in
powering the motors.

The saving made is equivalent to
the square of the speed reduction,
meaning that a speed reduction of
only 20% (which is usually possible)
creates close to a 50% energy
reduction.