Characterised by low rate variations, this application, initially at fixed speed, had little potential to achieve
energy savings.

SEMEA manages the treatment and the distribution of water over the greater
Angouleme conurbation. The company wanted to replace a system
made up of two motors and a pump which was used for supplying the water tower at Ruelle on Touvre.

Didier HEISSAT, sales manager for Flowserve in Nantes says: “To be able to improve the energy efficiency, you need a pump
characteristic curve which is not too flat. We
selected a 300LNN600 model which is part of our eco design approach and uses split case technology. It
has a capacity of 500 to 1100m3/h. We also defined the best motor speed according to the pump capacity
and the network.”

Leroy-Somer replaced the two motors by a single permanent magnet synchronous motor
PLSRPM 315 with a power rating of 350kW and 1500rpm speed. It was decided to control it with an
inverter Powerdrive MDS 470T to manage the variable flow rates, even if, in the case of SEMEA,
flow rate is most often stable.

Michel LABET, production manager at SEMEA, says: “Power
consumption is reduced by 10% per cubic metre transferred. Moreover the pump provides a higher water
flow of 15%, which enables us to better benefit from the 8h night rate.”