ABB motors and variable speed
drives are saving Pfizer €28,000 a
year on electricity costs for chillers at
its Ringaskiddy plant, County Cork.

The chillers use circulation pumps
to pump heat transfer fluid to and
from the cold storage tank. Pfizer
asked ABB drives and motors vendor
Caltech, in association with EMSA
Consultants, to investigate the
possibility of reducing energy use.

An energy appraisal found that
the application included three 45kW
motors and one 37kW motor, all of
them run with soft starters. The
pumps needed to maintain a flow
rate of 185m3/h, but the pumps were
rated for 240m3/h. To achieve
optimum flow rate, gate valves were
used to throttle the pumps.

EMSA, in conjunction with Pfizer
Process Engineering, decided to open
the valves fully and use VSDs to
maintain optimum flow. They found
they could achieve the desired flow
rate by running the motors at 35Hz
rather than 50Hz.

EMSA used ABB’s Pumpsave
energy saving calculation program,
which predicted an energy saving of
50% per motor, with cost savings for
each motor of around €7200.

Caltech’s turnkey solution included
high efficiency ABB EEx de IE2
motors laser aligned with the pumps.