Quick Start GuideNP Plus™ Non-Pressurized Variable Speed Kit

The NP Plus variable speed flow center kit is a self-contained package, designed to significantly reduce installation time for variable speed flow centers. All components necessary for piping to the ground loop and controlling the pump are included. Please read this quick start guide in its entirety before attempting to install the flow center.

1. Verify package contents. Included in the package is the flow center, controller/panel, external 3-way valve, as well as all of the fittings needed for connecting to the ground loop and heat pump hose kit (or Flo-Link adapters), shown in Figure 1.

2. Complete ground loop piping. Mount the 3-way valve on the wall or on the side of the flow center.

CAUTION: If mounting external 3-way valve on the flow center, use only the sheet metal screws supplied in the hardware bag to avoid penetrating the tank. The lag bolts supplied are for wall mounting only.

Connect the set of 1-1/4” PE fusion by Flo-Link double O-ring fittings to the ground loop at the “To Ground Loop” and “From Ground Loop” connections in Figure 1.

CAUTION: Do not install the piping at an angle to the flow center or 3-way valve con-nections to avoid possible leaks or damage to the connections.

3. Complete heat pump piping. Install the flow center elbow on the left side of the flow center, and flow sensor/adapters at the bottom of the 3-way valve. The heat pump connections require a Flo-Link hose kit or Flo-Link adapters if hard piping. Connect hose kit/adapters to the female Flo-Link fittings labeled “From Heat Pump” and “To Heat Pump” in Figure 1.

NOTE: The elbow and straight fittings with thermistors are zip-tied to the controller panel. Care must be ex-ercised to avoid ripping the wires from the controller when removing the fittings. Therefore, the 3-way valve should be mounted near the panel, and the panel should be near the flow center elbow (left hand side). When installing the fittings into the 3-way valve and flow center, notice that the thermistors are pre-wired, and could be pulled from the controller if not careful.

WARNING: MAKE SURE HEAT PUMP POWER IS DISCONNECTED BEFORE PROCEEDING TO STEP #4.

4. Wire low voltage connections. For flow rate control (flow sensor), connect using 18 gauge 4 conductor thermo-stat wire to terminals ACC, Y2, C, and R from the heat pump to the terminal strip (Figure 2). For temperature control (∆T), connect ACC, C, and R (Y2 not needed). Connect the PWM cable (blue, brown, and black wires - prewired to the controller) to the pump pigtail 4-pin connector. If included, plug in cable to flow sensor (cable is pre-wired to controller).

Engineered Solutions • Making Geothermal Easier

page 1 of 4 P/N 3901 rev. 17OCT20163901-10-17-16

Engineered Solutions • Making Geothermal Easier

FromHeat Pump

ToHeatPump

ToGround

LoopFrom

Ground Loop

Panel Mount Controller with

and low voltage terminals Flo-Link x fusion ground loop adapters

PWM cable

Covers and Plugs

Flo-Linkdouble O-ring

thermistors

Flow

Sen

sor

NPV PLUS™ Variable Speed Kit

The NPV PLUS variable speed kit includes everything needed for heat pumps with 24 VAC controls. Simply select a hose kit or adapters (next

pump.

The NPV PLUS provides increased

GEO variable speed ECM circulator. When the heat pump is running at

drop, allowing the ECM motor to

Since two-stage heat pumps typi-cally operate at part load 80% of

reduced by 50% or more.

screen. Flow rate control or Delta-T

NP PLUS™ Non-Pressurized Flow Center

valves, pressure/vacuum relief cap, Flo-Link

more features ...

• 56% larger cap•

pump)• •

• NP series plus the added items)

•

3-wayFlushValve

PlusNon-PressurizedFlow Center

NP V2 NP Series

of non-pressurized

NP PLUS single pump

3-wayFlushValve

To/FromGround Loop

To/FromHeatPump

56%larger

cap

Figure 1: Packagecontents and pipingarrangment

WARNING: MAKE SURE THAT HEAT PUMP POWER IS DISCONNECTED BEFORE PROCEEDING TO STEP #5.

5. Complete high voltage wiring to variable speed pump. Run high voltage wiring from the “L” side of the compressor contactor (see CAUTION below) to the pump terminals (refer to Figure 3). Wiring must meet all applicable code requirements, including requirements for wire protection, such as conduit. Wire size must be at least 14 AWG copper conductor.

CAUTION: DO NOT CONNECT THE VARIABLE SPEED PUMP TO THE “T” SIDE OF THE HEAT PUMP CONTAC-TOR. THE VARIABLE SPEED PUMP MUST BE POWERED AT ALL TIMES. AFTER VERIFYING THAT THE HEAT

PUMP BREAKER AND WIRE SIZE IS SUFFICIENT FOR BOTH THE HEAT PUMP AND THE FLOW CENTER PUMP(S), CONNECT THE VARIABLE SPEED PUMP TO THE “L” SIDE OF THE CONTACTOR.

6. Complete high voltage wiring to second pump (if appli-cable). If a second pump is installed, the second pump must be wired to the Grundfos controller, so that the relay in the controller can engage/disengage the pump based upon heat pump operation (for example, first or second stage operation/flow rate). Refer to Figure 4 for wiring. Run high voltage wiring from the “L” side of the compressor contactor to the Grundfos controller terminals. Run wiring from the controller to the second pump. Wiring must meet applicable code requirements, including requirements for wire protection, such as conduit. Wire size must be at least 14 AWG copper conductor.

7. Complete flushing/purging of ground loop piping. Do not attempt to start the pump(s) until the system has been filled and purged of air. Refer to Geo-Flo’s flush cart manu-al at www.geo-flo.com.

L2L1From “L” side of heat pump contactor

Variable SpeedHigh VoltageConnections

Figure 3: Variable Speed PumpHigh Voltage Connections

R C

+ - 10 DCIN

24VAC INGNDAUXILIARY

L1 L2 N1 N2OUT OUT ININ

208-230 VAC Input/OutputPower to UPS26-99 (2nd pump)for two pump flow centers. Donot connect Magna GEO single

pump flow center to thisterminal block.

Line

Vol

tage

Wiri

ng

(Fro

m “L

” sid

e of

con

tact

or)

UPS26-99 (2nd pump)Do not connectMagna GEO pump

230Vpump

to these terminals.

Figure 4: High Voltage to 2nd pump

page 2 of 4 P/N 3901 rev. 17OCT2016

To Heat PumpTo Earth Ground

Figure 2: Low Voltage Wiring

Important Notes: 1. Controller must be grounded.2. For heat pumps without an accessory

terminal (ACC), connect terminal ACC at the panel mount flow center to the 24VAC side of the compressor contactor coil (see pages 3 & 4).

Plug CableInto Sensor

Plug PWM cable into pump pigtail

page 3 of 4 P/N 3901 rev. 17OCT2016

8. Program Grundfos controller. Refer to the Grundfos UPC-GEO Controller installation manual that ships with the panel mount flow center package for programming details.

9. Test the heat pump/flow center. Verify flow center/heat pump operation in both heating and cooling modes. Controller will display heat pump operating mode (first or second stage), as well as entering/leav-ing water temperatures and flow rate (if equipped with flow sensor). Record start up data for future refer-ence.

Important Wiring Notes for Variable Speed Flow Centers:Heat Pumps Without an Accessory Terminal

Many geothermal heat pumps have an accessory terminal (sometimes labeled “A” or “ACC”). One of the purposes for the accessory terminal is for control of a solenoid valve for open loop systems. However, it also affects the operation of the Grundfos UPC-GEO variable speed pump controller. This page and the next will address wiring for systems without an accessory terminal.

The accessory terminal is typically connected to the output from the lockout board to the compressor contac-tor coil (labeled “CC” in the example below). The compressor contactor is only energized after the anti-short cycle delay, and if there are no lockouts. If the water solenoid is connected between “C” (common) and the heating/cooling thermostat terminal (”Y” or “Y1”), the solenoid will be energized any time there is a thermo-stat call. Most of the time, this approach works fine. However, if the heat pump is locked out, the water will continue to run even when the compressor is locked out, potentially causing substantial use of water and elec-tricity for the pump. Therefore, using the “CC” connection to engage an accessory ensures that the solenoid valve will not open if the unit is locked out. NOTE: This only applies to solenoid valves without an end switch. Solenoid valves with an end switch must be wired to the thermostat heating/cooling terminals.

A similar issue could occur with the variable speed pump controller. If the heat pump is locked out, and the controller is in temperature difference (∆T) mode, the thermostat will continue to call, but there will be no ∆T because the compressor is off. Once the heat pump is reset, the controller may not be able to react quickly enough, potentially causing insufficient water flow. When an accessory terminal is used, the control will only be enabled when the compressor contactor is energized.

If the heat pump being installed/serviced does not have an accessory terminal, review Figures 5 and 6 for alter-nate wiring. In Flow mode, using the thermostat signal for heat pumps without an accessory terminal will not cause a potential low flow problem. However, the pump will run even if the unit is locked out. Therefore, the accessory wiring diagrams below are still recommended for optimal operation even in Flow mode.

Geo-Flo Products Corporation905 Williams Park DriveBedford, Indiana 47421, U.S.A.www.geo-flo.com

page 4 of 4 P/N 3901 rev. 17OCT2016

230VAC

230VAC

Orange* Yellow* Red*

R

SPST Relay #1 SPST Relay #2

PumpPowerBlock

C FieldSuppliedRelay(s)**(230V coil)

RC ACC Y2

From heat pumpcircuit board

or transformer

Field Wiring (low voltage)Field Wiring (high voltage)

Not all brands have the same wire colors for the pump power block.Orange = 230 VAC (common)Yellow = 230VAC (switched) for 1st stageRed = 230VAC (switched) for 2nd stageRelay #1 needed for temperature di�erence mode; both relays neededfor �ow mode.

*

**

Figure 6: Connections for heat pumps without an external compressor contactor (compressor relay is on the circuit board), and without an accessory relay

LP1 HP2HP1YLP2 FLOWSWITCH

LPS

HP

S

FLO

W

T-STAT

NO

STATUS

TEST

YES

C R CCFAULT

FaultContactor

Coil

CCCompressorContactor

Coil

24 VAC

230 VAC

Use for ACCconnection*

Find an easyto accessCommon (C)connection*

*May require a “piggyback” spade connector.

Typical WSHP Lockout Board Without an Accessory Terminal

Figure 5: Connections for heat pumps with an external compressor contactor, but without an accessory relay

Important Wiring Notes for Variable Speed Flow Centers:Enertech Combination Heat Pumps / Flow Center in Flow Mode

Enertech combination heat pumps use terminals Y1 and Y2 for the thermostat, but terminal HW for the aqua-stat connection. Therefore, in hot water mode (2nd stage operation), the flow center will receive an ACC signal when the compressor contactor is energized, but it will never receive a Y2 signal, since Y2 is not received from the aquastat (only HW), and the flow center will maintain the flow rate for first stage, even though hot water mode operates in full load. Current production models of Enertech combination heat pumps include a terminal for a second stage solenoid valve as shown below in Figure 8 (terminal NC). For combination heat pumps with a variable speed flow center in flow mode (set points include GPM for first stage and GPM for second stage), connect terminal NC at the heat pump to terminal Y2 at the flow center. The ACC terminal will be the same as all Enertech heat pumps (connect the A terminal at the heat pump to terminal ACC at the flow center). The Y2 connection is not necessary for flow centers using Delta-T mode.

39CT Models, Rev.: A Enertech Global

Section 8: Controls

Connect terminal NC to flow center terminal Y2

Connect terminal A to flow center terminal ACC

Figure 8: Connections for Enertech combination heat pumps