Grundfos Magna Installation And Operating Instruction

8
5. Control of twin-head pumps
It is possible to connect two single-head pumps so that they operate as a
twin-head pump.
Fit a GENI module in the terminal box of each of the two single-head pumps
and connect the modules using a wire.
Master pump (the pump which is going to start first) connection: Connect a
jumper across terminals “X” and “Q”, see example on page 105.
Slave pump connection: Connect the pump as shown in the example on
page 106.
The pumps can be set to one of the following operating modes:
• Alternating operation. Pump operation alternates every 24 hours. If the
duty pump stops due to a fault, the other pump will start.
• Standby operation. One pump is operating continuously. In order to pre-
vent seizing-up, the other pump will start at a fixed frequency. If the duty
pump stops due to a fault, the other pump will start.
The operating mode is selected by means of a mechanical contact in each
module. The contacts in the two modules must be set to the same position.
If the contacts are positioned differently, “Standby operation” is selected.
Fig. 4
Operating the pump:
The connected pumps can be set and operated in the same way as single-
head pumps. The duty pump uses its setpoint setting, whether it was made
by means of the control panel, via the R100 or via bus.
Note: Both pumps should be set to the same setpoint and control mode.
Different settings will result in different operation when changing between
the two pumps.
TM02 0243 0904
Standby operation
Alternating operation

Grundfos Magna Specifications

General

Frequency	50/60 Hz
Temperature Range	-10 °C to +110 °C
Type	Circulator Pump
Maximum Operating Pressure	10 bar
Insulation Class	F
Series	Magna
Material	Cast iron
Voltage	1 x 230 V / 3 x 400 V (depending on model)