Maritime Geothermal ATF Series Manual

ECO 000266/000274: 1-Mar-2020 Page 1 002000MAN-02
Maritime Geothermal Ltd.
P.O. Box 2555, 170 Plantation Road
Petitcodiac, NB E4Z 6H4
[phone]
ATF-Series
Triple Function Central Air Source Heat Pump
Two-stage R410a 60Hz
Model Sizes 45-75
[email protected]
www.nordicghp.com
002000MAN-02
ECO 000266/000274: 1-Mar-2020
Installation and Service Manual

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ACE—65—P—1/6—KDE—xx
WARNING: Ensure all access panels are in place and properly secured before applying power to the unit.
Failure to do so may cause electrical shock.
WARNING: Before performing service or maintenance on the system, ensure all power sources
are DISCONNECTED. Electrical shock can cause serious personal injury or death.
WARNING: Refrigeration systems contain refrigerant under high pressure and as such can be hazardous
to work on. Only qualified service personnel should install, repair, or service the heat pump.
CAUTION: Safety glasses and work gloves should be worn at all times whenever the system is serviced.
A fire extinguisher and proper ventilation should be present whenever brazing is performed.
CAUTION: Venting refrigerant to atmosphere is illegal. A proper refrigerant recovery system must be
employed whenever repairs require removal of refrigerant from the equipment.
SAFETY PRECAUTIONS
Model Nomenclature
Series:
ACE = All weather Condenser / Evaporator
(air source outdoor unit)
Nominal Size:
45 = for AT_-45
55 = for AT_-55
65 = for AT_-65
75 = for AT_-75
Voltage Code:
1/6 = 220~277-1-50/60
Air Coil:
S = Standard
K = Coated
Blower Type:
D = Direct Drive
Blower Motor:
E = ECM (Variable Speed)
Revision:
01, 02 etc.
ATF—65—HACW—P—1T—C—SDELF—xx
Series:
ATF = Air to Triple Function
Nominal Size:
45 = 030 compressor
55 = 040 compressor
65 = 051 compressor
75 = 060 compressor
Functions:
H = Heating
AC = Active Cooling
W = Domestic Hot Water
Refrigerant:
P = R410a
Voltage Code:
1 = 230-1-60
2 = 208-3-60
4 = 460-3-60
6 = 220-1-50
7 = 380-3-50
Compressor:
S = 1 Stage Scroll
T = 2 Stage Scroll
Hydronic Coil:
C = Copper
Y = CuNi coil & piping
Z = CuNi coil only
Air Coil:
S = Standard
K = Coated
Blower Type:
D = Direct Drive
Blower Motor:
E = ECM (Variable Speed)
Air Return Orientation:
L = Left Return
R = Right Return
Air Outlet Orientation:
F = Field Configurable
(top or side)
Revision:
01, 02 etc.

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Maritime Geothermal Ltd. has a continuous improvement policy and reserves the right to modify specification
data at any time without prior notice .
APPLICATION TABLE - INDOOR UNIT
MODEL REFRIGERANT VOLTAGE COMPRESSOR HYDRONIC
COIL
AIR COIL/
BLOWER/AIR
RETURN
AIR
RETURN REVISIONS
ATF-45 P
1
2
4
T
C
Y
Z
S D E L
R 04
ATF-55 P
1
2
4
T
C
Y
Z
S D E L
R 04
ATF-65 P
1
2
4
T
C
Y
Z
S D E L
R 04
ATF-75 P
1
2
4
T
C
Y
Z
S D E L
R 04
This manual applies only to the models and revisions listed in this table.
FUNCTION
H A C W
H A C W
H A C W
H A C W
AIR
OUTLET
F
F
F
F
APPLICATION TABLE - OUTDOOR UNIT
MODEL REFRIGERANT VOLTAGE AIR COIL BLOWER TYPE BLOWER MOTOR REVISIONS
ACE-45 P 1/6 S
K D E 03
ACE-55 P 1/6 S
K D E 03
ACE-65 P 1/6 S
K D E 06
ACE-75 P 1/6 S
K D E 07
This manual applies only to the models and revisions listed in this table.
APPLICATION TABLE - FIRMWARE AND PC APP
Firmware Version Associated PC APP Version
MGT GEN2 Bootload Firmware V3.26+ MGT GEN2 PC APP V1.70+

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Tables & Documents ........................................... 5
ATF System Description ..................................... 6
General Overview ................................................................................. 6
1. Air Heating Mode .............................................................................. 6
Auxiliary Air Heat ............................................................................ 6
Defrost Operation ............................................................................ 6
2. Hydronic (Water) Heating Mode ....................................................... 6
Auxiliary Hydronic Heat .................................................................. 6
3. Air Cooling Mode .............................................................................. 7
Factory Options .................................................................................... 7
Mode & Priority Selection ..................................................................... 7
ATF Sizing ............................................................ 8
Air Source Heat Pumps ........................................................................ 8
Heat Pump Sizing ................................................................................. 8
Plenum Heater Sizing ........................................................................... 8
Installation Basics ............................................... 9
Sample Bill of Materials ........................................................................ 9
Unpacking the unit ................................................................................ 9
Indoor Unit Placement .......................................................................... 9
Placement of Tanks .............................................................................. 9
Indoor Unit Air Outlet Orientation & Air Return Orientation ................. 10
001915INF - Internal Plenum Heater Installation ................................ 11
Outdoor Unit Placement ..................................................................... 12
Outdoor Fan Speed Reduction ........................................................... 12
Outdoor Unit Mounting Height ............................................................ 12
Average Max. Snow Depth Map - Canada ......................................... 13
Wiring .................................................................. 14
Indoor Unit Power Supply Connections .............................................. 14
Outdoor Unit: Power Connections ...................................................... 14
Plenum Heater: Power Connections .................................................. 14
Plenum Heater: Signal Connections ................................................... 14
Indoor Loop Circulator Pump Wiring .................................................. 14
Control Transformer ........................................................................... 15
BACnet Connections .......................................................................... 15
Disable Switch (field installed) ............................................................ 15
Setpoint Control (Hydronic Control) Connections ............................... 15
Setpoint Control: Aux. Connections .................................................... 15
Outdoor Unit: Signal Connections ...................................................... 16
Air Thermostat Connections ................................................................ 16
Aquastat Connections (Optional) ........................................................ 16
002071CDG - Typical GEN2 Thermostat Connections ....................... 17
002304CDG - Typical ATF Wiring ....................................................... 18
002375QSS - Eco Ultra Tanks: Getting Started .................................. 19
002067CDG - Typ. Heating Only Zone Wiring (Setpoint) .................... 20
002069CDG - Typ. Htg. Only Zone Wiring (Hardwired) ...................... 21
Piping ................................................................... 22
Indoor Loop Water Lines ..................................................................... 22
Condensate Drain ............................................................................... 22
Domestic Hot Water (Desuperheater) Connections ........................... 22
002305PDG - Typical Piping Connections - ATF ................................ 23
002366PDG - Recommended Buffer Tank Piping ............................... 24
000538PDG - Buffer Tank Piping - Multiple Units ............................... 25
002367PDG - Auxiliary Boiler Piping ................................................... 26
000530PDG - Typical Zone Types ...................................................... 27
001055PDG - Connection to On-Demand DHW Tank ........................ 28
000970PDG - Desup. Conn. to DHW Pre-Heat Tank .......................... 29
002384PDG - DHW Pre-Heat Tank - Multiple Units ............................ 30
Outdoor Unit Line Set ........................................ 31
Line Set Interconnect Tubing ............................................................... 31
Indoor Unit Connections ...................................................................... 31
Outdoor Unit Connections ................................................................... 31
Oil Traps .............................................................................................. 31
Filter-Dryer ........................................................................................... 31
Pipe Insulation .................................................................................... 32
Silver Soldering Line Sets .................................................................. 32
Pressure Testing ................................................................................ 32
Vacuuming the System ........................................................................ 32
Charging the System ........................................................................... 32
002250CDG - Typical Line Set Connections ....................................... 33
Ductwork ............................................................. 34
Indoor Unit Blower Motor .................................................................... 34
Duct Systems - General ..................................................................... 34
Table of Contents
Duct Systems - Grill Layout ................................................................. 34
Thermostat Location ........................................................................... 34
Plenum Heater ..................................................................................... 34
002249PDG - Typical Duct & Condensate Connections ..................... 35
Duct Sizing Guide ................................................................................ 36
Operation ............................................................. 37
BACnet Control ................................................................................... 37
Air Thermostat Operation ................................................................... 37
Hydronic Temperature Control ........................................................... 37
1. Hydronic Heating: Setpoint Control ................................................ 37
Setpoint Control Method 1 - Indoor Loop (ICR) ............................ 37
Setpoint Control Method 2 - External HTS/CTS .......................... 37
Top Up S1 Function ..................................................................... 38
Summer Setback ......................................................................... 38
Outdoor Reset ............................................................................. 39
2. Hydronic Heating: Signals Control .................................................. 39
PC Application (PC App) .................................... 40
LCD Interface & Menus ....................................... 52
BACnet Interface .................................................. 54
Startup Procedure ............................................... 58
Startup Record .................................................................................... 60
General Maintenance .......................................... 61
Troubleshooting Guide ...................................... 62
Repair Procedures .............................................. 75
Pumpdown Procedure ........................................................................ 75
General Repair Procedure .................................................................. 75
Vacuuming & Charging Procedure ..................................................... 75
Compressor Replacement Procedure ................................................ 76
Outdoor Fan Replacement Procedure ................................................ 76
Control Board Replacement Procedure .............................................. 77
LCD Interface (Display) Board Replacement Procedure .................... 78
Model Specific Information ................................ 79
Shipping Information ........................................................................... 79
Refrigerant Charge ............................................................................. 79
Indoor Loop Flow Rates ...................................................................... 79
Operating Temperature Limits ............................................................ 79
Sound Levels (dBA) ............................................................................ 79
Pressure Drop Data ............................................................................. 80
Standard Capacity Ratings ................................................................. 80
Performance Tables: ATF-45 .............................................................. 81
Performance Tables: ATF-55 .............................................................. 83
Performance Tables: ATF-65 .............................................................. 85
Performance Tables: ATF-75 .............................................................. 87
Electrical Specifications ...................................................................... 89
Plenum Heater Electrical Specifications ............................................. 89
Indoor Airflow Data ............................................................................. 90
Wiring Diagram (208/230-1-60) .......................................................... 91
Electrical Box Layout (208/230-1-60) ................................................. 92
Wiring Diagram (208-3-60) ................................................................. 93
Electrical Box Layout (208-3-60) ........................................................ 94
Wiring Diagram (460-3-60) .................................................................. 95
Electrical Box Layout (460-3-60) ........................................................ 96
ACE (Outdoor Unit) Wiring Diagrams .................................................. 97
Refrigeration Circuit - Air Heating Mode .............................................. 98
Refrigeration Circuit - Air Cooling / Defrost Mode ................................ 99
Refrigeration Circuit - Hydronic Heating Mode .................................. 100
Dimensions .......................................................................................... 94
Appendix A: Control Board Description ..... 101
Appendix B: USB Driver Installation ............. 105
Appendix C: PC App Installation ................... 106
Appendix D: Updating Firmware ..................... 107
Updating Firmware via PC App ........................................................ 107
Updating Firmware via Jumper Pins .................................................. 109
Warranty ........................................................................ 110

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Tables & Documents
Table 1 - Heat Pump Size vs. Heated Area .................................................................................................................... 8
Table 2 - Plenum Heater Sizing ..................................................................................................................................... 8
Table 3 - Power Supply Connections .......................................................................................................................... 14
Table 4 - Outdoor Unit Power Supply Connections ..................................................................................................... 14
Table 5 - Plenum Heater Signal Connections .............................................................................................................. 14
Table 6 - Indoor Loop Circulator Connections ............................................................................................................. 14
Table 7 - Control Transformer ..................................................................................................................................... 15
Table 8 - BACnet Connections .................................................................................................................................... 15
Table 9 - Setpoint Control: Aux. Connections .............................................................................................................. 15
Table 10 - Outdoor Unit Signal Connections ............................................................................................................... 16
Table 11 - Air Thermostat Connections ....................................................................................................................... 16
Table 12 - Aquastat Connections (Optional) ................................................................................................................ 16
Table 13 - Buffer Tank Size ......................................................................................................................................... 22
Table 14 - Line Set Sizing ............................................................................................................................................ 31
Table 15a - 3-way Service Valve Tooling .................................................................................................................... 31
Table 15b - 3-way Service Valve Torques ................................................................................................................... 31
Table 16 - Extra Charge for Model Sizes 25-45 .......................................................................................................... 32
Table 17 - Extra Charge for Model Sizes 55-75 .......................................................................................................... 32
Table 18 - Heat Pump Size vs. Hot Air Grills ............................................................................................................... 34
Table 19 - Duct Sizing Guide ....................................................................................................................................... 36
Table 20 - Typical Temperature Setpoints ................................................................................................................... 38
Table 21 - Maximum Output Temperature ................................................................................................................... 38
Table 22 - BACnet Objects - Control Signals (Read/Write) .......................................................................................... 54
Table 23 - BACnet Objects - Operation Mode Description (Read Only) ....................................................................... 54
Table 24 - BACnet Objects - Data (Read Only) ............................................................................................................ 55
Table 25 - BACnet Objects - Alarm Descriptions (Read Only) ..................................................................................... 56
Table 26 - BACnet Objects - Fault Descriptions (Read Only) ....................................................................................... 57
Table 27 - Shipping Information - Indoor Unit .............................................................................................................. 79
Table 28 - Shipping Information - Outdoor Unit ........................................................................................................... 79
Table 29 - Refrigerant Charge ..................................................................................................................................... 79
Table 30 - Indoor Loop Flow Rates ............................................................................................................................. 79
Table 31 - Operating Temperature Limits .................................................................................................................... 79
Table 32 - Outdoor Unit Sound Levels (dBA) .............................................................................................................. 79
Table 33 - Indoor Unit Sound Levels (dBA) ................................................................................................................. 79
Table 34 - Hydronic Loop Pressure Drop Data ............................................................................................................ 80
Table 35 - Standard Capacity Ratings - Air Heating (60 Hz) ....................................................................................... 80
Table 36 - Standard Capacity Ratings - Air Cooling (60 Hz) ....................................................................................... 80
Table 37 - Standard Capacity Ratings - Hydronic Heating (60 Hz) ............................................................................. 80
Table 38 - ATF-Series Electrical Specifications ........................................................................................................... 89
Table 39 - Plenum Heater Electrical Specifications ..................................................................................................... 89
Table 40 - Airflow Range for Stage 2 (Full Load) ........................................................................................................ 90
Table 41 - Airflow Range for Stage 1 (Part Load) ........................................................................................................ 90
Table 42 - Airflow Range for Stage 3 (Auxiliary) .......................................................................................................... 90
Table 43 - Airflow Range for Fan Recirculation ........................................................................................................... 90
Table 44 - Airflow Range for Emergency ..................................................................................................................... 90
Table 45 - Indoor Airflow Reduction for Outdoor Temperature ..................................................................................... 90
Table A1 - Control Board Connector Descriptions (Top) ............................................................................................ 110
Table A2 - Control Board Connector Descriptions (Left Side) .................................................................................. 110
Table A3 - Control Board Connector Descriptions (Bottom) ...................................................................................... 111
Table A4 - Control Board Connector Descriptions (Right Side) ................................................................................. 112
001915INF - Internal Plenum Heater Installation .......................................................................................................... 11
002071CDG - Typical Thermostat Connections to GEN2 Board .................................................................................. 17
002304CDG - Typical ATF Outdoor Unit, Auxiliary Heat, and Indoor Circulator Wiring ............................................... 18
002067CDG - Typical Zone and Auxiliary Wiring with GEN2 Setpoint Control (Heating Only) .................................... 20
002069CDG - Typical Zone and Auxiliary Wiring with GEN2 Hardwired Option (Heating Only) .................................. 21
002305PDG - Typical Piping Connections - ATF ......................................................................................................... 23
002366PDG - Recommended Hydronic Buffer Tank Piping ........................................................................................ 24
000538PDG - Typical Buffer Tank Configuration - Multiple Units ................................................................................ 25
002367PDG - Auxiliary Boiler Piping ........................................................................................................................... 26
000530PDG - Typical Zone Types for Hydronic Applications ....................................................................................... 27
001055PDG - Single Unit Connection to On-Demand DHW Pre-Heat Tank................................................................ 28
000970PDG - Desuperheater Connection to DHW Pre-Heat Tank ............................................................................. 29
002384PDG - Desuperheater Connection to DHW Pre-Heat Tank - Multiple Units .................................................... 30
002250CDG - Typical ATA/ATF to Outdoor Unit Line Set Connections ....................................................................... 33
002249PDG - Typical Duct & Condensate Connections ............................................................................................. 35
001956SCH - ATF-Series Schematic Diagram 208/230-1-60 ..................................................................................... 91
001957ELB - ATF-Series Electrical Box Diagram 208/230-1-60 ................................................................................. 92
001958SCH - ATF-Series Schematic Diagram 208-3-60 ............................................................................................ 93
001959ELB - ATF-Series Electrical Box Diagram 208-3-60 ........................................................................................ 94
001960SCH - ATF-Series Schematic Diagram 460-3-60 ............................................................................................ 95
001961ELB - ATF-Series Electrical Box Diagram 460-3-60 ........................................................................................ 96
001951SCH - ACE Outdoor Unit Schematic Diagram ................................................................................................. 97
002014SCH - ACE 4-Fan Outdoor Unit Schematic Diagram ...................................................................................... 97
001844RCD - ATF-Series Refrigeration Circuit - Air Heating Mode ............................................................................ 98
001845RCD - ATF-Series Refrigeration Circuit - Air Cooling / Defrost Mode ............................................................. 99
001846RCD - ATF-Series Refrigeration Circuit - Hydronic Heating Mode ................................................................ 100
Tables
Documents

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General Overview
The ATF-Series heat pump is an air source heat pump
that can heat or cool via a forced air duct system, as well as
heat water for hydronic application like in-floor heating. It is the
air-source version of the geothermal Nordic TF-series, which is
a unique product with a long history of reliable operation.
Being an air source heat pump, it does not require a
ground loop, instead using an outdoor evaporator / condenser to
exchange heat with the outdoor air. Unlike most air source out-
door units on the market, this outdoor unit contains only an air
coil, ECM hub motor fan, heating mode electronic expansion
valve (EEV), and an outdoor temperature sensor.
The remaining components, including the compressor and
all electronics, are contained in the indoor unit. This has several
advantages: minimal installation and service work must be per-
formed outdoors, important components are in the conditioned
space for longevity, antifreeze is not required in the hydronic
loop, and domestic hot water (desuperheater circuit) is possible
since the fresh water lines are inside and will not freeze.
The air heating and cooling functions are controlled by a
standard 3H/2C 24V room thermostat. The hydronic heating
control is done by an internal routine that maintains the buffer
tank temperature, without external sensors (’Setpoint Control’).
BACnet or an external aquastat can also be used.
In additional to the main hydronic water heating function,
there is a double-wall desuperheater for pre-heating domestic
hot water with ~5% of the heat pump’s capacity. This function is
only active when the heat pump is running for space heating or
cooling purposes. An energy-efficient bronze head ECM circ
pump for the desuperheater circuit is built in, along with a tem-
perature control to turn the pump off when the DHW tempera-
ture reaches 140°F (60°C).
A two-stage scroll compressor is standard. The outdoor
air coil is e-coated for corrosion protection, and the coaxial hy-
dronic heat exchanger is copper / steel with optional CuNi inner
tube available. The cabinet is powder coated galvanized sheet
metal. Control is overseen by the Nordic GEN2 programmable
control board, which has many advanced features like laptop
connectivity via the free PC App software, data logging & gra-
phing, and real time readout from electronic temperature & pres-
sure sensors. A premium electrically commutated (ECM) blow-
er motor with adjustable airflow is standard.
1. Air Heating Mode
In air heating mode, the heat pump heats warm air in a
duct system. Superheat is controlled by the heating EEV locat-
ed in the outdoor unit while the EEV in the indoor unit is set to
full open. As the unit operates, heat is extracted from the out-
door air, which causes the air coil to eventually frost up to the
point that a defrost cycle is required. The time between defrost
cycles varies depending on the outdoor conditions; refer to the
Defrost Operation section below.
If the outdoor temperature is above 34°F(1°C), the outdoor
unit fan starts and stops when the heat pump starts and stops.
If the temperature is below 34°F(1°C), the outdoor fan will re-
main on at a very slow speed when the heat pump is off in order
minimize the chance of a fan freeze up, and to prevent snow
from entering the unit through the fan opening during a snow
storm. The outdoor fan is controlled based on the suction pres-
sure and will slowly ramp up to the required speed when the
system starts.
ATF System Description
Auxiliary Air Heat
An electric resistance plenum heater, placed inside the
heat pump but ordered separately, is required. This is because
the capacity of air source heat pumps fall as the outdoor tem-
perature drops and the heating load increases. This output re-
duction can be seen in the performance charts later in this man-
ual, and is common to all air source heat pumps. The plenum
heater will be sized to satisfy all of the heat load if the outdoor
temperature falls below the minimum for heat pump operation:
-7°F (-22°C).
A second important function of the plenum heater is to
provide heat to the indoor air steam during defrost mode
(described below), to avoid cold air blowing into the space. It
will also provide emergency heat in the unlikely event of a heat
pump problem.
The room air thermostat controls when the plenum heater
is activated, normally due to a drop in the room temperature.
The heater is installed inside the indoor unit, unless the blower
is installed in the side discharge position, in which case it is in-
stalled in the air discharge ductwork outside the heat pump.
See the Sizing, Wiring, and Ductwork sections.
Defrost Operation
The heat pump has an advanced defrost control algorithm
intended to provide a minimal number of defrosts and minimal
defrost cycle time, while achieving complete defrost. The out-
door unit’s unique design also has excellent resistance to coil
freeze-ups and potential future air coil damage as a result of
repeated freeze-ups.
The system uses the outdoor temperature and suction
pressure to determine when a defrost cycle should occur as well
as how long it should be. PID fan control allows the discharge
pressure to rise quickly and then be maintained at a desired
setpoint for quick defrosting. A “defrost disabled” period occurs
after a defrost cycle which allows a potential problem with the
unit to be identified as an alarm to prevent repetitive defrost
cycles.
The outdoor unit has a unique design for combatting ice
build up, which is a common cause of damage to air source
heat pumps. The coil sits on a 15° angle and the area below
the coil is completely open (no drip tray). This causes the melt-
ing frost/snow to run down the back of the coil, which creates a
single line of runoff along the back bottom edge of the coil rather
than along the entire bottom side of the coil. Runoff occurs
more quickly and at a higher velocity, minimizing the amount
that remains trapped at the bottom of the coil due to surface
tension between the coil fins, and re-freezing is prevented.
2. Hydronic (Water) Heating Mode
In hydronic heating mode, the heat pump heats hot water
in the buffer tank. EEV, outdoor fan, and defrost operation are
the same as in air heating mode.
Auxiliary Hydronic Heat
Optionally, hydronic auxiliary heat may be installed, to
keep the floor warm no matter what the outdoor temperature.
This can consist of electric elements in the buffer tank, or an
existing boiler may be retained and piped in parallel with the
heat pump.
Auxiliary hydronic heat will be controlled by the heat pump
via dry contacts. Buffer tanks with elements rated for space
heating duty are available as accessories.

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3. Air Cooling Mode
In air cooling mode, the heat pump cools air through the
duct system. Superheat is controlled by the cooling EEV located
in the indoor unit while the EEV in the outdoor unit is set to full
open. As the unit operates, heat is extracted from the air
stream and rejected to the outdoor air. There is no defrost cycle
in air cooling mode.
The outdoor fan is controlled based on the discharge pres-
sure and will slowly ramp up to the required speed when the
system starts. During operation, the fan speed will automatical-
ly adjust up or down to in order to maintain the discharge pres-
sure setpoint value. The discharge pressure will begin to rise
above the setpoint when the outdoor temperature exceeds the
point at which the outdoor fan speed reaches its maximum val-
ue. Two stage units will drop down to the first stage to reduce
the discharge pressure at very high outdoor temperatures.
Factory Options
Looking at the main service panel, the indoor unit can be
ordered as a left or right hand air return from the factory. This
must be specified at time of order as the physical construction of
the two configurations is different. See Installation Basics chap-
ter.
Mode and Priority Selection
The heat pump can be set to Air or Hydronic priority. Units
are shipped set up for air priority. This is often a good setting,
since drops in the household air temperature normally occur
sooner if there is a lag in the ducted air system than if there is a
drop in the hydronic water temperature.
However, if there is only an auxiliary air plenum heater
installed (no hydronic auxiliary heat), the heat pump can be set
to hydronic priority, so that the heat pump will heat in-floor water
first and any shortfall in heating capacity on cold days will be
covered by the air plenum heater.
Whenever there is a stage 1 demand from both the air
thermostat and aquastat, the unit steps up to stage 2 of the pri-
ority mode in order to satisfy the priority demand quickly and get
to the non-priority mode. If this functionality was not present,
the unit could run in stage 1 of the priority mode (67% compres-
sor capacity) for a long time with a ‘call waiting’, allowing the
overall supply of heat to the building to fall behind the load.
SINGLE MODE OPERATION:
If there is only one mode being called for, the unit operates
in the mode and stage that is called for.
SIMULTANEOUS DEMANDS - AIR PRIORITY:
If there is a call for:
 both stage 1 air and stage 1 hydronic
 both stage 2 air and stage 1 hydronic
 both stage 1 air and stage 2 hydronic
 both stage 2 air and stage 2 hydronic
The unit operates in air mode in stage 2.
SIMULTANEOUS DEMANDS - HYDRONIC PRIORITY:
If there is a call for:
 both stage 1 air and stage 1 hydronic
 both stage 2 air and stage 1 hydronic
 both stage 1 air and stage 2 hydronic
 both stage 2 air and stage 2 hydronic
The unit operates in hydronic mode in stage 2.

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ATF Sizing
This is an estimate of which unit size is required for a typi-
cal two-level home (main level and below grade basement) with
R-20 walls, R-40 ceiling and average size and number of win-
dows. The Heated Area is the area of the main level. The table
accounts for a basement the same size as the heated area.
It is highly recommended that a heat loss/gain analy-
sis be performed by a qualified person with software using
the CSA F-280 or Manual J methods before selecting a heat
pump size. The analysis will result in a heat load for the cold-
est day, which is influenced by, for example, the number of lev-
els, the size of the windows, the orientation of the home, at-
tached garage, bonus rooms, walk-out basement, and coldest
outdoor temperature for the region.
In northern climates, a heat pump model size can be se-
lected by matching the calculated heat load to the heat pump’s
heating capacity at an outdoor temperature of 35°F (1.7°C) and
an indoor water temperature of 105°F (40.5°C) for concrete in-
floor heating or 120°F (49°C) for other heating types. These
numbers can be found in the detailed performance tables in the
Model Specific Information section later in this manual.
This sizing will result in a good compromise between covering
as much of the cold weather heat load as possible without utiliz-
ing backup heat, while minimizing excessive cycling (turning on
and off frequently) during moderate outdoor temperatures.
It should be noted that sizing an air source heat pump is
always a compromise between covering coldest-day heat load
and minimizing cycling due to over-capacity in warm weather.
In cooling dominant climates, the heat pump should be
similarly sized, by matching the calculated cooling load to the
standard capacity rating at an outdoor temperature that matches
the local maximum outdoor temperature. The difference here is
that it is necessary to cover all of the cooling load, since there is
no backup cooling.
Air Source Heat Pumps
Since it is harder to extract heat from colder outdoor air,
any air source heat pump will have its lowest heating capacity
on cold days when building heat load is the highest. It is not
generally possible to oversize an air source heat pump to cover
100% of the coldest day heat load, since this would mean ex-
cessive compressor short-cycling during moderate outdoor
weather when heat pump capacity is much higher and heat load
is much lower, and also poor dehumidification during cooling
mode.
Therefore, it should be expected that any air source heat
pump will need auxiliary heat on the coldest days. An air
side plenum heater is required; see reasons in previous chapter.
Hydronic side auxiliary can also be implemented (tank elements
or auxiliary boiler).
Heat Pump Sizing
The table shows the size of home each air source heat
pump model size is generally suitable for, in northern climates.
TABLE 1 - Heat Pump Size vs. Heated Area
Model sq.ft. m2
25 800 75
55 2,000 185
65 2,600 240
75 3,100 290
45 1,400 130
Plenum Heater Sizing
The required plenum heater is available as an accessory
in 5, 7, 10, 15 and 20kW sizes. Choose a size that covers
100% of the coldest day heat load, according to the heat
loss analysis mentioned in the last section. If that is not availa-
ble, use the following recommendation:
TABLE 2 - Plenum Heater Sizing
Model
Plenum Heater Size (kW)
Recommended Internally Possible
45 10 5, 7, 10
55 10 5, 7, 10, 15, 20
65 15 5, 7, 10, 15, 20
75 20 5, 7, 10, 15, 20
Two styles of plenum heater are available; the first is for
internal installation (inside the indoor unit). Note limit for size 45
in above table.
The second has a wider element profile for installation
outside the unit, in the ductwork. If field-installing the fan in the
convertible side discharge position, this type of plenum heater
will need to be used.
Even in northern heating dominant climates, it should
be ensured that 100% of the cooling load will be covered
when sizing the heat pump.

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Installation Basics
Unpacking the Unit
When the 2-piece heat pump reaches its destination it
should be unpacked to determine if any damage has occurred
during shipment. Any visible damage should be noted on the
carrier's freight bill and a suitable claim filed at once.
Indoor Unit Placement
Ducted or forced air heat pumps should be centrally located
in the home with respect to the conditioned space. This provides
the best in economy and comfort and usually can be
accomplished in harmony with the design of the home. A
heating system cannot be expected to produce an even temper-
ature throughout the building when it is located at one end of the
structure and the heated or cooled air is transmitted with
uninsulated metal ductwork.
If possible the front access panel and side access panel
opposite the air return should remain clear of obstruction for a
distance of 2 ft (0.7 m) to facilitate servicing and general
maintenance. No access is required on the back side. Ensure
the unit is level to eliminate any possible condensate draining
issues.
The heat pump comes equipped with an air filter rack which
can be installed with the removable end (where the filter is in-
serted) on either side to facilitate changing the filter. Be careful
not to run piping in front of the filter rack access cover, since
access is required in order to change the air filter.
Raising the indoor unit off the floor a few inches is generally
a good practice since this will prevent rusting of the bottom
panel of the unit and deaden vibrations. An anti-vibration pad,
available as an accessory, or a piece of 2” styrofoam should be
placed under the unit.
Placement of Tanks
See ATF System Description and Piping chapters for ex-
ample placements of the hydronic buffer tank and domestic hot
water preheat and final tanks.
WARNING: Pool chemicals should be stored
in a different room from the PC unit to pre-
vent premature corrosion problems.
WARNING: Pool chemicals should be inject-
ed downstream of the PC unit.
Sample Bill of Materials
Although not exhaustive, following is a list of materials needed
for a typical installation:
FROM MARITIME GEOTHERMAL
• ATF SERIES HEAT PUMP (L OR R RETURN)
W/ACE OUTDOOR UNIT
• PLENUM HEATER __kW
• AIR THERMOSTAT (WIFI OR STD)
• SHIELDED 18-8 WIRE FOR OUTDOOR UNIT
• BUFFER TANK W/ELEMENTS __kW
OPTIONAL FROM MARITIME GEOTHERMAL
• ANTI-VIBRATION PAD FOR UNDER UNIT
• SOUND JACKET
• COMPRESSOR SECURE START
• ELECTROSTATIC (CLEANABLE) AIR FILTER
DUCTWORK
• OUTLET PLENUM ADAPTER W/ FLEXIBLE COLLAR
• RETURN AIR ADAPTER W/ FLEXIBLE COLLAR
• FIBREGLASS INSULATION (FOR NOISE, IF REQ’D)
• TRUNK DUCT W/ JOINERS (IF NOT EXISTING)
• 6” ROUND DUCT W/ADAPTERS (IF NOT EXISTING)
• ALUMINUM TAPE
• SHEET METAL SCREWS
DHW:
• PREHEAT TANK, 40 OR 60 GAL
• ½” COPPER PIPE
• ½” FITTINGS, BALL VALVES, BOILER DRAINS, CV
ELECTRICAL
• HEAT PUMP SERVICE WIRE: 6-2/3 OR 8-2/3
• PLENUM HEATER SERVICE WIRE
• 14-2 OUTDOOR RATED WIRE W/ DISCONNECT
SWITCH FOR OUTDOOR UNIT
• HEAT PUMP BREAKER
• PLENUM HEATER BREAKER
• THERMOSTAT WIRE 18-8
• THERMOSTAT WIRE 18-3 (PLENUM HEATER)
• FORK TERMINALS FOR TSTAT WIRE (6)
• CONDENSATE PUMP & HOSE (IF REQUIRED)
REFRIGERATION
• 1/2” & 7/8” (OR 3/8” & 3/4”) ACR TUBING
• PIPE ISULATION
• EXTRA R410A REFRIGERANT FOR LINESETS >25 FT
HYDRONIC ZONES
• CIRCULATOR: HEAT PUMP TO TANK
• 1” PIPE & FITTINGS: HEAT PUMP TO TANK
• ZONE CIRCULATOR(S)
• ZONE TRANSFORMER & CIRC CONTACTOR
• ZONE VALVES (IF NOT INDIVIDUAL PUMPS)
• IN-FLOOR PIPING
• ZONE THERMOSTATS
• RELAYS OR ZONE CONTROLLER
• ZONE SUPPLY & RETURN HEADERS:
1” COPPER PIPE & FITTINGS
• PIPE & FITTINGS TO ZONES
• EXPANSION TANK
• 2” STYROFOAM INSUL. (IF PAD NOT PURCHASED)

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Indoor Unit Air Outlet Orientation
The indoor unit has a field configurable blower position,
resulting in top or side air discharge. Its default location from
the factory is in the top of the unit, providing a “ninety” in the
airflow. It can easily be placed in the side of the unit for straight
through airflow. Note that if this is done, plenum heater will
need to be placed in ductwork outside unit.
To switch the location of the fan outlet:
1. Turn the power of to the unit.
2. Remove the screw that holds the side access panel in
place and remove the access panel by pulling up on
the handle and then outward from the bottom.
3. Disconnect the two wire harnesses and ground wire
from the fan motor.
4. Repeat step 2 for the access panel with the fan
mounted in it. Set the assembly on the floor.
5. Disconnect the plenum heater extension from the fan
housing and from the access panel.
6. Mount the fan housing directly to the access panel.
7. Install the fan/panel in the new location and secure
with the screw.
8. Reconnect both harnesses and ground wire.
9. Install the remaining access panel and secure with the
remaining screw.
Air Return Orientation
The heat pump can be ordered as left or right air return
from the factory. This must be specified at time of order as the
physical construction of the two configurations is different. Re-
fer to the Dimensions section toward the end of this manual for
physical dimensions of the units.
LEFT RETURN RIGHT RETURN
BLOWER IN
TOP DISCHARGE
POSITION (DEFAULT)
BLOWER IN
SIDE DISCHARGE
POSITION

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Outdoor Unit Placement
The ACE outdoor unit must be placed outdoors, with the
fan pointing away from the building. It should be at least 8 inch-
es (20 cm) and preferably 12 inches (30 cm) away from the
building or other obstructions on the back and sides for unim-
peded return airflow. If mounted at less than 12 inches from
building, there is a risk of frost forming on the wall during defrost
under certain conditions.
There should be little or no obstruction in the fan (front)
direction for at least 10 feet (3 m), and preferably 15 feet (4.5
m), otherwise airflow and therefore overall performance will
be reduced.
In addition, there should be at least two feet (0.6 m) of
clearance on the electrical box and refrigeration piping side of
the unit to facilitate servicing and general maintenance.
The outdoor unit must be bolted down to prevent a tipping
hazard. See next section.
Note that no field installed filter-dryer is required, since
one is included in the indoor unit.
Leg Kit Installation
Outdoor Unit Mounting Height
The outdoor unit must remain clear of snow and ice at all
times. Good performance depends on good airflow, which of
course cannot be achieved if the unit is buried in snow and re-
frozen defrost condensate.
There are several ways to accomplish this. First, look up
how much snowfall is expected in your area, either from local
knowledge or weather data. The snowfall map included on next
page can be used as a rough guide for Canada.
1. If the local climate has less than ~4” / 10 cm of snow
accumulation, the unit may be mounted directly on a
concrete pad. This is not recommended, since in this
case constant and ongoing care must be taken to
ensure re-frozen condensate does not build up under
unit.
2. The unit can be mounted on angle brackets attached
to the side of a building. Be sure to adhere to the
minimum clearance requirement of 8-12” (20-30 cm),
and use brackets designed for twice the unit weight.
3. Two different leg kits which add either 15” (38 cm) or
30” (76 cm) of additional height are available as an
accessory from Maritime Geothermal Ltd.
To attach the legs, first remove the three bolts with flat
washers that hold each foot plate in place. Leaving the foot
plate in place on the inside of the cabinet panel, slide the leg
over the outside of the panel and re-install the three bolts and
flat washers.
Whether or not a foot kit is used, be sure to mount the unit
using the 4 rubber grommets included with the unit, to dampen
any vibration. The unit must be fastened to its mounting surface
with four min. 5/16” bolts through these grommets to pre-
vent a tipping hazard due to impact or high wind.
IMPORTANT NOTE: The line set between the
indoor and outdoor units must not exceed 70
ft (21 m) in length.
Outdoor Unit
Fan Orientation
Outdoor Fan Speed Reduction
Should fan noise be a concern, for example if the outdoor
unit is mounted near a frequently open window, the outdoor fan
speed can be reduced (up to a maximum of 25%). This should
only be done if necessary, since a small loss in efficiency will
result.
The fan speed can be reduced via the LCD (see LCD In-
terface & Menus section) or PC App (see PC Application
section).

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Average Maximum Snow Depth - Canada (1979-1997)
Source: Natural Resources Canada

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Wiring
IMPORTANT NOTE: A properly qualified
electrician should be retained for all
connections to the heat pump and associat-
ed controls. The connections to the unit
MUST CONFORM TO LOCAL CODES.
TABLE 3 - Power Supply Connections
Line Description Voltages
L1 Line 1 All
L2 Line 2 All
L3 Line 3 3-phase only
GND Ground All (connect to ground lug)
* Only required if connecting 115VAC circulators.
N Neutral 208/230-1-60*, 208-3-60*,
460-3-60, 380-3-50
Indoor Unit Power Supply Connections
Power supply for the heat pump from the breaker panel is
supplied to the indoor unit. The unit has a concentric 1.093” /
0.875” knockout for main power supply connection to the electri-
cal box. There are also two 7/8” knockouts and a 1/2” opening
with plastic grommet (grommet hole is 3/8”) for connections to
the air thermostat, indoor loop circulator, optional aquastat, and
power and signal connections to the outdoor unit.
A schematic diagram (SCH) and electrical box layout
diagram (ELB) can be found on the electrical box cover of the
unit as well as in the Model Specific Information section of this
manual.
The Electrical Tables in the Model Specific Information
section contain information about the wire and breaker size.
Indoor Loop Circulator Pump Wiring
The indoor unit has provisions for connecting the indoor
circulator pump (between the heat pump and buffer tank) so that
it will be turned on whenever the compressor operates. Con-
nect the circulator pump module to the appropriate two terminals
(115V & 115/230 or 230V & 115/230) of the terminal strip
marked Indoor Circulator Pumps. Ground wires should be con-
nected to the ground lug in the electrical box. Ensure that the
total current draw does not exceed the value indicated on the
label in the heat pump electrical box.
For 460VAC models, only 277VAC circulators may be
powered directly from the heat pump. If other voltage circulators
are used, they must be powered using an external contactor
actuated by the ICR terminal on the left side of the control board
and the C (24V ground) terminal.
TABLE 6 - Indoor Loop Circulator Connections
Signal Description
115V
230V
Use a 2-conductor 14ga cable.
Connection for 115V circulator
Connection for 230V circulator
115/230 Connection for 115V or 230V circulator
TABLE 4 - Outdoor Unit Power Supply Connections
Line Description
L1 Supply line
L2 Supply line
GND Ground
Use a two conductor outdoor rated 14ga minimum cable.
IMPORTANT NOTE: According to most
codes, a disconnect switch visible and/or
reachable from the outdoor unit must be in-
stalled in the power supply cable. If the
switch has fuses or breakers they must be
no more than 10A.
Outdoor Unit: Power Connections
The ACE outdoor unit is powered from the indoor unit.
The power supply for the ACE unit is 208 to 277VAC, 50/60Hz.
The ATF and ACE units have matching terminal strips for these
connections. Use a two conductor, minimum 14ga outdoor rat-
ed cable for this connection. Refer to diagram.
Plenum Heater: Power Connections
Auxiliary air heat will usually be provided by an electric
duct heater (plenum heater). These are available as accesso-
ries in 5, 7, 10, 15, and 20 kW sizes, and are installed as previ-
ously noted in this manual. The plenum heater will have its own
breaker and power supply wire. The Electrical Tables in the
Model Specific Information section contain information about
the size of wire for the connections, as well as the recommend-
ed breaker size.
Plenum Heater: Signal Connections
The ATF unit has two dry contacts to control the 2 stages
of the plenum heater. These dry contacts can also be used to
control other types of auxiliary air heat. Note that dry contacts
are intended to activate equipment that has its own 24VAC
TABLE 5 - Plenum Heater Signal Connections
Signal Description
CP Common
1
2
Use a 3-conductor 18ga cable.
Dry contact for auxiliary heat stage 1
Dry contact for auxiliary heat stage 2
OUTDOOR DISCONNECT SWITCH IS A
SAFETY DEVICE ONLY. Turn off breaker to
indoor unit before servicing to avoid costly
damage to electronic control board.

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TABLE 7 - Control Transformer
Voltage Low Voltage Circuit Protection
(1) 208/230-1-60 Resettable breaker on transformer
(2) 208-3-60 Resettable breaker on transformer
(4) 460-3-60 Primary / Secondary fuses
(6) 220-1-50 Primary / Secondary fuses
(7) 380-3-50 Primary / Secondary fuses
BACnet Connections
If using BACnet for external control of heating/cooling de-
mand and/or monitoring of status, use a shielded twisted pair to
the connector at the bottom left of control board. There is an
optional termination jumper located above the connector.
See the BACnet Interface section for details.
TABLE 8 - BACnet Connections
Line Description
A Communication +
B Communication -
GND Ground
Use a shielded twisted pair cable.
Control Transformer
The low voltage controls, including the control board, are
powered by a 100VA class II transformer. 208/230-1-60 and
208-3-60 models have a resettable breaker on the secondary
side for circuit protection. If the breaker trips, locate and correct
the problem and then reset the breaker by pressing in on it.
All other voltage models have primary and secondary fus-
es for circuit protection.
IMPORTANT NOTE: For 208/230VAC-1-60
units, if connecting to 208VAC power supply
move the red wire connected to the 240 ter-
minal of the transformer to the 208 terminal
of the transformer.
Setpoint Control (Hydronic Control)
Connections
If using the on-board Setpoint Control routine with sam-
pling to control buffer tank temperature, no external temperature
probe or aquastat is required.
Note that an external buffer tank temperature sensor may
be used to replace the internal water OUT line temperature sen-
sor for use with the Setpoint Control routine. This is called Ex-
ternal HTS/CTS Setpoint Control.
See Operation chapter for details.
TABLE 9 - Setpoint Control: Aux. Connections
Signal Description
C 24VAC common (ground)
1A Hydronic Auxiliary (hot)
D1 Hydronic Auxiliary dry contacts
D2
Use a 2-conductor 18ga cable.
Setpoint Control: Aux. Connections
When using Setpoint Control, there are 2 methods for acti-
vating hydronic auxiliary heat. See diagram on a following
page.
First, a 24VAC signal on terminal 1A (with C as ground/
common) is available to power the coil of an external contactor
to operate hydronic auxiliary heat. Choose this method if using
a heating device that doesn’t have its own electronic controller
or control transformer, e.g. a bare heating element in the buffer
tank. This signal can provide a maximum of 500mA at 24VAC.
1A defaults to OFF when heat pump is powered off.
Second, a dry contact on terminals D1 and D2 is available,
to actuate a heating device that has its own controller and trans-
former. In general, these types of devices will have their own
electronic temperature controller. Connection will be made to
that device’s E-E terminals or similar. D1-D2 defaults to ON
when heat pump is powered off. Therefore, it is necessary to
set the temperature control on the external heating device to a
limiting value, e.g. 125°F, and adjust its settings so it is only
activated by the heat pump’s controller. This method should be
used for the Thermo2000 EcoUltra tank that is available
from Maritime Geothermal as an accessory; see the setup
instruction sheet that comes with tank and on following page.
D1-D2 defaults to ON and so must be used with
an auxiliary heating device that has a HIGH TEM-
PERATURE LIMITER to avoid a serious safety
hazard.
Disable Switch (field installed)
A switch to disable demand from the control system may
be installed. On control board, jumper COM_IN to GND, and
toggle 12VDC to IN_SPARE to disable. See the main wiring
diagram in the Model Specific Information section.
If it is not desired to have D1-D2 default to ON when heat
pump is powered off, make the following wiring changes in the
heat pump’s electrical box, while referring to the Wiring/
Schematic diagram in the Model Specific Information chap-
ter.
 Find the light brown wire connected between terminal strip
terminal D1 and the Elec. Aux. Relay. Move it from pin 5 to
pin 2 of the relay.
 Find the purple wire connected between the left side of the
control board and the Elec. Aux. Relay. Move if from termi-
nal L4 (NOT_HYD_AUX) to DO_2 (HYD_AUX) on the con-
trol board. [It will share DO_2 with a brown wire.]
Now D1-D2 will work as before, but will default to OFF when
heat pump is off.
High Temperature Hydronic Auxiliary Heat
If using a high temperature hydronic auxiliary device that
can only be activated when heat pump compressor is off (for
example because the outdoor temperature is too cold), an
SPDT relay may be connected to provide a dry contact for high
temperature device activation by the heat pump’s control board.
Refer to diagram 002304CDG on a following page and
wiring/schematic diagram in the Model Specific Information sec-
tion. Connect the external relay’s coil (normally relay pins 1 and
3) to DO_3 (AUX ONLY) and LC at the left side of control board.
Then use the COM and NC relay contacts (normally pins 4
and 5) to enable the high temperature heating device when the
DO_3 (AUX_ONLY) pin is off, meaning compressor is off
and auxiliary heat is being called for.

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TABLE 11 - Air Thermostat Connections
Signal Description
C 24VAC common (ground)
R 24VAC hot
G Fan low speed (for air recirculation)
Y1 Heat pump stage 1
Y2 Heat pump stage 2
W2 Heating stage 3 (plenum heater)
O Cooling mode (reversing valve)
E Emergency heat (plenum heater)
L Fault (24VAC when fault condition)
AR Airflow reduction: connect AR1 to AR2 with a
dry contact to reduce the airflow for zoning. Con-
nections located on control board.
24VAC
TABLE 12 - Aquastat (Signals Control) Connections
Signal Description
C/CA 24VAC common (ground)
R/RA 24VAC hot
Y1A Compressor ON (Part Load)
Y2A Compressor bump up to Stage 2 (Full Load)
Air Thermostat Connections
A three-stage heating and two stage cooling heat pump
configurable thermostat is required. The stages are S1 = stage
1 compressor, S2 = stage 2 compressor and S3 = electric auxil-
iary (in heating mode only). One can be ordered with the unit,
or other heat pump thermostats with the same number of stages
can be used. The air thermostat connections are located on a
terminal strip in the indoor unit. Refer to diagram on a following
page for connections between the thermostat and the heat
pump.
The air flow can be further reduced by an adjustable
amount between 5 and 20% (value set in PC App) by making a
dry contact across 24VAC and AR on the right side middle ter-
minal strip of the control board. This can be used for applica-
tions that have multiple air zones.
Care should be taken to ensure that the unit does not trip a
safety control in heating or cooling mode if the AR reduction is
used in conjunction with lower air flow settings.
Aquastat Connections (Optional)
Most installations will use the internal Setpoint Control
routine to control buffer tank temperature, in which case no aq-
uastat is required. However, an aquastat or aquastats can be
used if required, for example if heating two loops with different
setpoint temperatures. This is called Signals Control.
The wiring connections are at the top right of the ATF’s
control board, on the screw terminal connector section marked
AQUASTAT. This is shown on the wiring (SCH) diagram in
the Model Specific Information section. The external device
needs to send the 24VAC signal from RA back to the Y1A and
Y2A terminals to call for the two stages of hydronic heating.
C or CA is the common or ground terminal for powering the
external device.
Outdoor Unit: Signal Connections
The speed of the fan and the heating mode expansion
valve (EEV) in the outdoor unit are controlled by the control
board in the indoor ATF unit, and a temperature sensor is read.
Therefore, communication wiring is required.
The indoor and outdoor units have matching terminal
strip signals for these connections. Connect an 8 conductor
shielded outdoor rated cable (supplied) between the termi-
nal strip in the ATF and the terminal strip in the Outdoor Unit.
The signals are marked as Outdoor Unit Signal Connections on
the ATF terminal strip. The shield ground wire is connected
only to the indoor unit; do not connect the shield ground to
the outdoor unit (there is no terminal for it). Simply cut the
shield ground wire short at the cable sheath in the Outdoor Unit.
TABLE 10 - Outdoor Unit Signal Connections
Signal Description
EEVR Electronic Expansion Valve (Red)
EEVG Electronic Expansion Valve (Green)
EEVW Electronic Expansion Valve (White)
EEVB Electronic Expansion Valve (Black)
TR Outdoor Temperature Sensor (Power)
TG Outdoor Temperature Sensor (Signal)
TB Outdoor Temperature Sensor (Ground)
PWM+ Outdoor Fan Control
Shield GND* Shielded cable ground wire
* Connect only to the indoor unit. In the outdoor unit,
leave this wire unconnected and cut it short at the cable
sheath.

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