Grundfos Geo-Flo MAGNA3 User manual

Installation Information
Wiring
Plumbing
Start-Up
Control Mode Settings
Multi-Pump Setup
Faults
IM1542EW 04/15
MAGNA3 Insulated Pumps Installation Manual
MAGNA3
Insulated Pumps

MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
Table of Contents
Model Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
General Installation Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Determining the Pump Control Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Plumbing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Start-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Multi-Pump Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Antifreeze Selection and Use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Pressure Drop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Faults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
1 - 3
040 080 B
11 12
C
-
4 -10
M3S
Pump Series
M3S = Grundfos Magna3 single insulated pump
M3C = Grundfos Magna3 single insul. pump with check valve
Available Models
040-080 = 40-80 single head, 2” ball isol. valves, 2” NPT connections
040-120 = 40-120 single head, 2” ball isol. valves, 2” NPT connections
040-180 = 40-180 single head, 2” ball isol. valves, 2” NPT connections
Note: Use model M3C for two pumps in primary/backup or cascade mode
Standard/Special
C = Cast iron volute
Voltage
B = 208-230/1/60
Model Nomenclature

5
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
The MAGNA3 pump is mounted on a wood base for shipment. Remove the four bolts that attach the pump to the wood base. Always
install the pump with motor shaft horizontal and the control box with the Grundfos logo in vertical position as shown below.
To rotate the pump head control box, loosen the screw in the clamp holding the pump head and pump housing together with a 5 mm Allen
wrench. WARNING: If the screw is loosened too much, the pump head will be completely disconnected from the pump housing. Carefully
rotate the pump head to the desired location. Position the clamp so that either the hole or the gap in the clamp is in a downward position.
Due to the pressure sensor wiring it is not recommended to move the clamp to the other side. See figure 1. Tighten the screw to minimum
6 + / - 0.7 ft-lbs (8 + / - 1 Nm)







Figure 1: Clamp
General Installation Information

6
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
Determining the Pump Control Mode
The MAGNA3 has a number of control modes for a variety of applications. However, for geothermal installations there are only two
control modes that are applicable, Constant Pressure and Constant Curve. Most of the other modes are for boiler applications, and
are not recommended.
Constant Pressure:
A central variable speed pump is common for geothermal applications of three or more heat pumps due to the opportunity for
energy savings. Figure 2 provides an example piping diagram. The central pump is controlled based upon pressure differential.
As the water valves open and close based upon the operation of the heat pump, the system pressure changes, causing the
pump to adjust speed to attain the water flow needed. For example, if only one of five heat pumps is running, the pump speed
adjusts to the flow rate needed for the one heat pump, dramatically reducing pump Watts compared to when the pump is running
at maximum flow.
Constant Curve:
Because the MAGNA3 uses a very efficient motor, the pump may be used as a constant speed pump in applications where
variable speed is not necessary or desired.
M
FCV
M
FCV
M
FCV
M
FCV
M
FCV
T T T T
Modulating
Water Valve Automatic Flow Control Valve Ball Valve
Heat
Pump
Ground Loop Piping
PD
VFD
T
Expan.
Tank
Two-Pipe System, Variable Speed Pump:
The central pump is controlled based upon pressure differential.As the modulating water valves
open and close based upon the operation of the heat pump, the system pressure changes,
causing the pump to adjust speed to attain the water flow needed for the number of heat pumps running.
2” 3-way valves
with flush ports
(2) FPL8
Figure 2: Typical central pump application, using constant pressure control and modulating water valves.

7
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
Figure 3: Control Box Front Cover
Figure 4: Start/Stop Jumper
Remove the 5 screws on the front cover of the control box with a T20 Torx driver. The Start/Stop jumper and electrical connections are
located beneath the cover. Before attaching power, remove the Start/Stop jumper located inside the pump control module (remove the
entire green plug with the grey jumper). This will prevent the pump from starting when powered.
Complete the high voltage wiring to the pump. Locate the power supply plug and conduit adapter in the box supplied with the pump.
Connect wiring from pump disconnect to the pump terminal block as shown in Figure 5. Pump terminals are labeled L, N, and ground
(symbol). Connect L to L1 and N to L2. Wiring must meet all applicable code requirements, including requirements for wire protection, such
as conduit. Wire and breaker/fuse size must be determined based upon pump nameplate ratings.
Wiring
VERIFY PUMP NAMEPLATE VOLTAGE BEFORE CONNECTING HIGH VOLTAGE WIRING.
L (L1)
N (L2)
Figure 5: High Voltage Wiring
5x T20 Screws
Start/Stop Jumper

8
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
Wiring cont.
For ease of setting up the pump it is best to leave the start/stop jumper in place until after the pump starts is completed. Once the
pump start up is completed, the start/stop jumper can be removed and the S/S and ground connections made. For multi-pump
configurations the start/stop will be used on the secondary pump.
There are two options available to turn on and off the MAGNA3 pump. Depending on the application loop pump linking or the
MAGNA3RELAY can be used to turn on and off the MAGNA3 pump.
Loop Pump Linking – NOTE: This feature is not available with the Aurora Base Controls (ABC only). Loop pump linking
can be achieved by connecting the SL terminals on connector P2 in both units with 2-wire thermostat wire. These terminals
are polarity dependent (see figure 6). The MAGNA3 pump will turn on when any of the linked units sees a call. Once the
call from all of the linked units has went away the pump will turn off. The installer will need to supply a SPST 230VAC coil
relay and two-conductor 18AWG thermostat wire (see figure 7).
NOTE: If high voltage is connected to the MAGNA3 S/S and ground terminals damage may occur the pump.
AXB to
Electromechanical Units
ToElectromechanical Unit
AXB to Premier
Unit #2 with Premier
Unit #1
with AXB Board Unit #1 with AXB Board Unit #1
with AXB Board
Unit #2
with AXB Board
AXB to AXB
CS
VSSLOSLI OUTIN C C
VSSLOSLI OUTIN C C
With pump
wired to
Unit 2
With pump
wired to Unit 1
VSSLOSLI OUTIN C C
With pump
wired to
Unit 1
With pump
wired to
Unit 2
VSSLOSLI OUTIN C C
Shut
Down CC
SL1
In SL1 Out
Figure 6: Loop Pump Linking
Two conductor thermostat wire
from N.O. relay contacts to Magna3
Start/Stop terminals (S/S and ground)
S/S
M
I
M
A
1
2
Two conductor thermostat
wire from terminal block PB1
in heat pump control box to
relay coil (230V coil)
230
VAC
PB1
IMPORTANT:
Must be 230VAC coil
SPST relay
(field supplied) Magna3
Figure 7
NOTE: If more than 2 heat pumps with AXB or Premier controls are loop pump linked, the remaining heat pumps will be daisy chained
together.

9
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
Wiring cont.
MAGNA3RELAY Board - The MAGNA3RELAY board is operated from a dry contact closure. The dry contact closure
can either be from the heat pump control accessory relay or from a SPST 230VAC coil relay. Wiring diagrams are shown
below for connecting to the accessory relay (Figure 8) or SPST 230VAC coil relay (Figure 7). Use two-conductor 18AWG
thermostat wire from the heat pump accessory relay to the relay board HP IN and OUT terminals. NOTE: When connecting
to the ABC accessory SW2-4 and SW2-5 must be in the “OFF” position (cycles with compressor).
HP-1 OUT
HP-1 IN
HP-2 OUT
HP-2 IN
HP-3 OUT
HP-3 IN
HP-4 OUT
HP-4 IN
HP-5 OUT
HP-5 IN
ACC NO
ACC COM
OUT
IN
Figure 8: Accessory relay to MAGNA3RELAY board

10
MAGNA3 INSULATED PUMPS INSTALLATION MANUAL
Wiring cont.
Use two-conductor 18AWG thermostat wire to connect the MAGNA3RELAY dry contacts to the S/S and ground terminals
on the MAGNA3 pump (see figure 9).
Figure 9: MAGNA3RELAY board dry contacts to MAGNA3
24 VAC
24 VAC
DRY CONTACTS DRY CONTACTS
PUMP RELAY PUMP RELAY PUMP RELAY PUMP RELAY
S/S
M
I
M
A
WARNING: MAKE SURE THAT POWER IS DISCONNECTED BEFORE WIRING PUMP ENABLE RELAY.
24
VA
C
24
VA
C
PUMP
RELAY
PUMP
RELAY
Not used with
MAGNA3 Pump