Grundfos Control MPC 2000 Series, Installation And Operating Instructions Manual

Page: 12 / 528

English (GB)
12
6. Overview of control variants
The examples below are based on booster systems.
Systems with speed-controlled pumps
Systems with pumps connected to one
CUE frequency converter
Systems with mains-operated pumps
Control MPC-E/-EC Control MPC-F Control MPC-S
E: Control MPC with three E-pumps.
EC: Control MPC with three pumps, each
connected to a Grundfos CUE frequency
converter. Control MPC with three pumps connected
to one Grundfos CUE frequency
converter. The speed-controlled operation
alternates between the pumps.
Control MPC with three mains-operated
pumps.
T
M
03
0
9
9
3
09
05
T
M
03
1
2
6
5
15
05
T
M
03
0
9
9
9
09
05
One E-pump in operation.
One pump connected to a Grundfos CUE
frequency converter in operation.
One mains-operated pump in operation.
TM
0
0
7
995
2
296
TM
0
0
7
995
2
296
TM
0
3
9
204
3
607
Three E-pumps in operation.
One pump connected to a Grundfos CUE
frequency converter and two mains-
operated pumps in operation.
Three mains-operated pumps in
operation.
TM0
0
799
6 2
2
9
6
TM0
0
799
8 2
2
9
6
TM0
3
920
3 3
6
0
7
• Control MPC-E/EC maintains a constant
pressure through continuous adjustment
of the speed of the pumps.
• The system performance is adjusted to
the demand through cutting in/out the
required number of pumps and through
parallel control of the pumps in operation.
• Pump changeover is automatic and
depends on load, operating hours and
fault.
• All pumps in operation run at the same
speed.
• The number of pumps in operation also
depends on the energy consumption of
the pumps. If only one pump is required,
two pumps will be running at a lower
speed if this results in a lower energy
consumption. This requires that the
differential pressure of the pump is
measured and pump curve data are
available for the controller.
• Control MPC-F maintains a constant
pressure through continuous adjustment
of the speed of the pump connected to the
Grundfos CUE frequency converter. The
speed-controlled operation alternates
between the pumps.
• A pump connected to the Grundfos CUE
frequency converter always starts first. If
the pressure cannot be maintained by the
pump, one or two mains-operated pumps
will be cut in.
• Pump changeover is automatic and
depends on load, operating hours and
fault.
• Control MPC-S maintains an almost
constant pressure through cutting in/out
the required number of pumps.
• The operating range of the pumps lies
between Hset and Hstop (cut-out
pressure).
• Pump changeover is automatic and
depends on load, operating hours and
fault.
PT PT PT
Q
H
Hset
Q
H
Hset
Q
H
Hstop
Hset
Q
H
Hset
Q
H
Hset
Q
H
Hstop
Hset