Danfoss VLT AQUA Operating Instructions Manual page 9

Application Types
2 2
Illustration 2.1 Control Circuit Alternating Lead Pump (4 Pumps)
Illustration 2.2 Mains Circuit Alternating Lead Pump (4 Pumps)
The fixed speed pump configuration provides a cost
effective method for controlling up to 9 pumps. It is able
to control system output by controlling the number of
running pumps as well as the speed of the single variable
speed pump.
In this configuration the VLT
variable speed pump and up to 8 fixed speed pumps. The
fixed speed pumps are staged and de-staged as needed
through contactors direct online. The variable speed pump
provides the finer level of control needed between the
stages.
The direct online pumps are staged or de-staged
depending on the feedback.
6
®
VLT AQUA Drive MCO 101/MCO 102
®
AQUA Drive controls one
®
MI38C402 - VLT is a registered Danfoss trademark
Illustration 2.3 Fixed Speed Pump Configuration Example