Nordic ATWC Series Installation And Service Manual
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Nordic ATWC Series Installation And Service Manual

High temperature air to water heat pump
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Installation and Service Manual
ATWC-Series
High Temperature Air to Water Heat Pump
R134a with Switchable R410a Cascade Mode
Model Sizes 45-100
Space Heating or Dedicated Domestic Hot Water Options
Maritime Geothermal Ltd.
info@nordicghp.com
P.O. Box 2555, 170 Plantation Road
www.nordicghp.com
Petitcodiac, NB E4Z 6H4
002536MAN-00
(506) 756-8135
PRELIMINARY: 24-Sep-2021
Page 1
002536MAN-00
PRELIMINARY
24-Sep-2021

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  • Page 1 Installation and Service Manual ATWC-Series High Temperature Air to Water Heat Pump R134a with Switchable R410a Cascade Mode Model Sizes 45-100 Space Heating or Dedicated Domestic Hot Water Options Maritime Geothermal Ltd. info@nordicghp.com P.O. Box 2555, 170 Plantation Road www.nordicghp.com Petitcodiac, NB E4Z 6H4 002536MAN-00 (506) 756-8135...
  • Page 2 SAFETY PRECAUTIONS 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 heat pump system, ensure all power sources are DISCONNECTED.
  • Page 3 APPLICATION TABLE - INDOOR UNIT SIZE FUNCTION REFRIGERANT VOLTAGE COMPRESSOR INDOOR REVISIONS COIL ATWC-45 H A C ATWC-55 H A C ATWC-65 H A C ATWC-75 H A C ATWC-80 H A C ATWC-100 H A C This manual applies only to the models and revisions listed in this table. APPLICATION TABLE - OUTDOOR UNIT MODEL REFRIGERANT...

  • Page 4: Table Of Contents

    Table of Contents Tables & Documents Operation ............5 ................32 1. BACnet Control ..............32 ATWC System Description ..........6 2. Signals / Hardwired Control ..........32 General Overview ..............6 3. Setpoint Control ..............32 1. Heating Mode ..............6 Setpoint Control Method 1 - Indoor Loop (ICR), One Tank ..

  • Page 5: Tables & Documents

    Tables & Documents Tables Table 1 - Heat Pump Size vs. Heated Area ....................8 Table 2 - Auxiliary Heat Sizing ........................ 8 Table 3 - Power Supply Connections ....................12 Table 4 - Outdoor Unit Power Supply Connections ................12 Table 5 - Indoor Loop Circulator Connections ..................

  • Page 6: Atwc System Description

    Unlike many other NORDIC heat pumps, there is no DHW and re-freeze between them, which a common cause of air coil desuperheater on the ATWC series. Instead there is the option failure in air source heat pumps. for a double wall condenser for dedicated DHW heating.

  • Page 7: One Or Two Buffer Tanks

    One or Two Buffer Tanks? This is an important design choice that needs to be made when planning an installation. These systems are described more fully in the following chapters. Single Buffer Tank Systems By far, this is how most systems are config- ured.

  • Page 8: Atwc Sizing

    ATWC Sizing Air Source Heat Pumps Even in northern heating dominant climates, it should be ensured that 100% of the cooling load will be covered Since it is harder to extract heat from colder outdoor air, when sizing the heat pump. (Note that ATWC models with any air source heat pump will have its lowest heating capacity the double wall condenser option, used for dedicated DHW on cold days when building heat load is the highest.

  • Page 9: Installation Basics

    • ZONE TRANSFORMER & CIRC CONTACTOR • ZONE VALVES (IF NOT INDIVIDUAL PUMPS) FROM MARITIME GEOTHERMAL • ZONE PIPING • ATWC SERIES HEAT PUMP W/ACEC OUTDOOR UNIT • OTHER AIR HANDLERS, DUCTING • SHIELDED DOUBLE TWISTED PAIR WIRE • ZONE THERMOSTATS •...

  • Page 10: Outdoor Unit Placement

    Outdoor Unit Placement Outdoor Unit Mounting Height The ACEC unit must be placed outdoors, with the fans The outdoor unit must remain clear of snow and ice at all pointing away from the building. There is a detachable cover for times.

  • Page 11: Average Max. Snow Depth Map - Canada

    Average Maximum Snow Depth - Canada (1979-1997) Source: Natural Resources Canada PRELIMINARY: 24-Sep-2021 Page 11 002536MAN-00...

  • Page 12: Wiring

    Wiring Indoor Unit Power Supply Connections Indoor Loop Circulator Pump Wiring The indoor unit has provisions for connecting the indoor Power supply for the heat pump from the breaker panel is circulator pump (between the heat pump and buffer/DHW tank) supplied to the indoor unit.

  • Page 13: Bacnet Connections

    BACnet Connections Setpoint Control: Aux. Connections If using BACnet for external control of heating/cooling de- When using Setpoint Control, there are 3 methods for acti- mand and/or monitoring of status, use a shielded twisted pair to vating hydronic auxiliary heat. See diagram on a following the connector at the bottom left of control board.

  • Page 14: Outdoor Unit: Signal Connections

    Outdoor Unit: Signal Connections Aquastat Connections (Optional) The speed of the fans and the two heating mode expan- Most installations will use the internal Setpoint Control sion valves (EEVs) in the outdoor unit must be controlled by the routine to control buffer tank temperature, in which case no aq- control board in the indoor unit, and a temperature sensor must uastat is required.

  • Page 15: 002543Cdg - Typical Atwc/Atw2 Series Wiring

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  • Page 16: 002375Qss - Altsource Tanks: Getting Started

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  • Page 17: 002067Cdg - Typ. Heating Only Zone Wiring (Setpoint)

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  • Page 18: 002068Cdg - Typ. Htg/Cooling Zone Wiring (Setpoint)

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  • Page 19: Piping

    Piping Number of Tanks TABLE 12 - Buffer Tank Size All dedicated DHW heat pumps (with the double wall con- Minimum Size Recommended Size Heat Pump Size denser option) require one DHW holding tank, equivalent in gal (L) gal (L) function to the single buffer tank systems discussed below.
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  • Page 21: 002540Pdg - Piping Connections - Space Heating/Cooling . 20 002366Pdg - Recommended Buffer Tank Piping

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  • Page 22: 002528Pdg - Buffer Tank Piping - Multiple Units

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  • Page 23: 002252Pdg - 2 Tank Piping With A Reversing Heat Pump

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  • Page 24: 002527Pdg - 2 Tank Piping W/Multiple Rev. Heat Pumps

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  • Page 25: 002367Pdg - Auxiliary Boiler Piping

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  • Page 26: 000530Pdg - Typical Zone Types

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  • Page 27: 002541Pdg - Piping Connections - Direct Dhw Heating

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  • Page 28: 002545Pdg - Tank Piping For Direct Dhw Heating

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  • Page 29: Outdoor Unit Line Sets

    Outdoor Unit Line Set Line Set Interconnect Tubing TABLE 14a - 3-way Service Valve Tooling Once both the indoor and outdoor units have been Line set Hex key to Charging Nominal Valve cap mounted, the 2 line sets may be run between them: one for connection open/ port cap...

  • Page 30: Pipe Insulation

    Pipe Insulation Charging the System All line set piping between the indoor and outdoor units The indoor unit is pre-charged for line sets up to 20 ft long. should be insulated with 3/8” thick closed cell pipe insulation to Once the system has been vacuumed, if additional amounts of prevent condensation and dripping onto floors or walls during each refrigerant are required due to the length of the line set, it the heating season.

  • Page 31: 002544Cdg - Typical Atwc Line Set Connections

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  • Page 32: Operation

    Operation 1. BACnet Control 3. Setpoint Control If using BACnet Control, the heat pump will turn the com- One of the features of the ATWC’s GEN2 Control Board is pressor(s) on and off and activate cooling mode when it is told built in temperature control functionality called “Setpoint Con- to by the building control system.

  • Page 33: Typical Atwc-Series Setpoints

    Setpoint Control window looks like this for Method 1 (Indoor Heating setpoints will vary widely by application. Lower Loop - ICR): indoor loop water temperatures may be able to be used, or high- er ones may be required. Lower heating setpoints will translate directly into a higher COP (efficiency).

  • Page 34: Outdoor Reset

    Outdoor Reset As mentioned earlier, lower heating setpoints will translate directly into a higher COP (efficiency). When Control Source HYD is set to Setpoints, an optional Outdoor Reset control algorithm is available for heating mode, which reduces the heating temperature setpoints at warmer outdoor temperatures as measured by the outdoor unit. To enable it, simply click on the Outdoor Reset button at the top of the Setpoint Control window.

  • Page 35: Setpoint Control Method 3 - External Hts/Cts, One Tank

    Setpoint Control window looks like this for Method 3 Setpoint Control Method 3 - External (HTS/CTS) (External HTS/CTS with One Tank): One Tank PC APP: Tools-->Configuration RED—heating BLUE—cooling LCD Interface: Configuration Cold Setpoints Indicators only visible for turn on This is the required method for when an ultra-high temper- reversing when a ature (>160°F/71°C) auxiliary boiler is connected in parallel with...

  • Page 36: Setpoint Control Method 4 - External Hts/Cts, 2 Tanks

    Setpoint Control window looks like this for Method 4 Setpoint Control Method 4 - External (HTS/CTS) (External HTS/CTS with Two Tanks): Two Tanks PC APP: Tools-->Configuration LCD Interface: Configuration Click on up/down Toggle arrows to adjust between “O” signal Like with Method 3, when this method is used no indoor Actual Setpoint control circulator control for temperature sampling will occur.

  • Page 37: Pc Application (Pc App)

    PC Application (PC App) NOTE: Before using the PC Application, refer to Appendix B & C for installation instructions for the PC Application and USB driver for the COM port. Both must be installed in order to run the PC App and communicate with the control board. Connect a USB cable between the PC and the control board USB connector located at the bottom center of the board.
  • Page 38 View Menu: This menu handles all of the operational viewing screens. Clicking on the View submenus will open the page in the PC APP’s frame. The next few pages of the manual show screenshots of each of the pages along with some descriptions of what is on each page. The main control panel window will open, shown below.
  • Page 39 View-->Alarms, Limits and Faults The alarms page has four tabs: ALARMS - Current alarm status, alarm count, high and low refrigeration alarm cutout values, and short cycle timer. ALARMS LIST - List of alarms that have occurred since the PC APP has been operating (this will be lost when the PC is discon- nected from the control board.) LIMITS - Limits in effect which prevent compressor operation but that do not cause an alarm.
  • Page 40 View-->Alarms, Limits and Faults (ALARMS LIST Tab): This tab show a history of alarms that have occurred since the PC APP was connected to the control board. This list will be lost when the PC APP is disconnected. Each alarm that occurs while This button will erase the the PC APP is connected to alarm events in the Alarm List.
  • Page 41 View-->Alarms, Limits and Faults (FAULTS tab): This tab shows hardware faults that could occur. If one of these faults occurs there may be a problem with the control board hard- ware, with LCD Display and buttons, or with a sensor. If a fault occurs, some things to try: ...
  • Page 42 View-->Water Lines Shows the water line temperatures. View-->Digital Inputs Shows the digital inputs and their individual status (ON/OFF). They may be individually controlled when in Manual Override Mode in order to facilitate troubleshooting. NEEDS View-->Digital Outputs Shows the digital outputs and their individ- ual status (ON/OFF).
  • Page 43 Graphs Menu: This menu is a list of the available graphs. Graphs are real-time and show a time stamp of when the recording started as well as a current time which will show up if the graph is screen captured. Each graph has a CLEAR button which will erase the stored data and restart the graph.
  • Page 44 Tools Menu: This is where various tools for system setup and monitoring are located. Tools-->Configuration (System Configuration tab): This is where the system setup is done. Settings should only be changed by a person who has a good understanding of system oper- ation.
  • Page 45 Tools-->Configuration (Alarms and Delays tab): Click on the UP/DOWN arrows to change the value, noting that values have both a low and high limit. The number of minutes before the The minimum off time when unit can start again after various switching between heating and Count Reduce Time is alarm shutdowns...
  • Page 46 Tools-->Calibration: Generally there is no need for calibration. The suction and discharge pressures may be calibrated in increments of 1 psi if there is a discrepancy in the readings when compared to a known good reference. Temperature sensors may be adjusted in increments of 0.1°F. There is an AUTO CALIBRATION routine in the program that continu- ally calibrates the temperatures sensors against an on board reference resistor by applying an offset to the temperature sensors.
  • Page 47 Tools-->Datalogging (Datalog tab): The datalog rate is set via the dropdown box at the top right of the PC App main window. Starting with firmware version 2.85, a log will be recorded at the datalog rate whenever the heat pump is powered on, making it easy to compare datalogs from multiple units . The maximum number of datalog records is 32,224, which will take 45 days to fill up at the default recording rate of 2 minutes.
  • Page 48 Tools-->Parameters: WARNING! The Parameters page is for advanced use only. Changing parameter values can cause the system to stop functioning properly. The parameters page shows all configurable memory spaces with their name and current value and allows them to be edited directly. To change a parameter value type in the new value and press ENTER.

  • Page 49: Lcd Interface & Menus

    LCD Interface & Menus These are examples of the unit status and operating data displayed when at the message display level (top level). Pressing ENTER will enter into the menu levels beginning with the Main Menu. 2x16 LCD Display NEEDS UPDATE ENTER button: DOWN button:...
  • Page 50 Menu Tree Continued ENTER ENTER ENTER ENTER Description (From Main) (First Press) (Second Press) (Third Press) Enable summer setback. Summer Setback — Enable Setback? — Enable (only if using Disable summer setback. — Disable Setpoint Control) Disable compressor, auxiliary and ICR. System EN/DIS —...

  • Page 51: Bacnet Interface

    BACnet Interface The BACnet interface is an MS/TP connection via RS-485 twisted pair. Recommended wire: 22-24 AWG single twisted pair, 100-120 Ohms impedance, 17pF/ft or lower capacitance, with braided or aluminum foil shield, such as Belden 9841 or 89841. The connector on the control board is a three wire removable screw connector. The signals are as follows: Communications line (+) (right pin) Communications line (-) (middle pin) C: Ground connection...

  • Page 52: Table 21 - Bacnet Objects - Data (Read Only)

    TABLE 21 - BACnet OBJECTS - DATA (Read Only) Name Property Units Description Data—Type Analog Input AI0 (Comp1_Current) Present Value Amps R410a compressor current draw (AI0) AI1 (Comp2_Current) Present Value User R134a compressor current draw (AI1) Present Value User User defined (0-5VDC or 4-20mA) Present Value User User defined (0-5VDC or 4-20mA)

  • Page 53: Table 22 - Bacnet Objects - Alarm Descriptions (Read Only)

    TABLE 22 - BACnet OBJECTS - ALARM Descriptions (Read Only) Name Data Type Description AI0 (Comp1 Current) Analog Input R410a status alarm (start / stop failure, from current sensor) AI1 (Comp2 Current) Analog Input R134a status alarm (start / stop failure, from current sensor) LPS1 Analog Input R410a low pressure alarm...

  • Page 54: Table 23 - Bacnet Objects - Fault Descriptions (Read Only)

    TABLE 23 - BACnet OBJECTS - FAULT Descriptions (Read Only) Name Data Type Description AI4 (Cold Tank) Analog Input Cold tank temperature sensor faulty or disconnected - requires accessory AI5 (Hot Tank) Analog Input Hot tank temperature sensor faulty or disconnected - requires accessory LPS1 Analog Input R410a low pressure sensor faulty or disconnected...

  • Page 55: Startup Procedure

    Startup Procedure The ATWC-Series Startup Record located in this manual is used in conjunction with this startup procedure to provide a detailed record of the installation. A completed copy should be left on site, a copy kept on file by the installer, and a copy should be sent to Maritime Geothermal Ltd.

  • Page 56: Unit Startup

    Unit Startup The unit is now ready to be started. The steps below outline the procedure for starting the unit and verifying proper operation of the unit. It is recommended that safety glasses be worn during the following procedures. IMPORTANT NOTE: The unit is shipped with the system DISABLED in order to prevent the unit from starting when the pow- er is first turned on.

  • Page 57: Startup Record

    Startup Record - ATWC-Series Two-Stage R410a Installation Site Startup Date Installer City Company Province Model Check boxes unless asked to record data. Country Serial # Circle data units. Homeowner Name Homeowner Phone # PRE-START INSPECTION Outdoor Unit Unit is securely mounted at least 8” from building, fans facing out Fan outlet is clear of obstructions Line Sets (2) Line set length, extra charge added (only if needed)

  • Page 58: Routine Maintenance

    Routine Maintenance MAINTENANCE SCHEDULE Item Interval Procedure Outdoor Unit Weekly Inspect for and clear away debris or leaves in air coil intake, and ice buildup under unit that is approaching air coil. Compressor 1 year Inspect for pitted or burned points. Contactors (2) Replace if necessary.

  • Page 59: Troubleshooting Guide

    Troubleshooting Guide WARNING: WHEN SERVICING THE OUTDOOR UNIT, BE SURE TO TURN OFF POWER TO THE INDOOR UNIT. The outdoor disconnect switch will not cut low voltage power, and damage to the control board will occur if the main heat pump breaker is not turned off during service. The following steps are for troubleshooting the heat pump.
  • Page 60 ALARM TROUBLESHOOTING Alarm/Fault Description Recommended Action The data logging function of the GEN2 Control Board is a very useful tool for troubleshooting alarms. It provides a history of the unit operation up to and including the time at which the alarm(s) occurred. Low Pressure: A low pressure alarm occurs when the suction pressure drops to Go to the Low Pressure sec-...
  • Page 61 FAULT TROUBLESHOOTING Alarm/Fault Description Recommended Action Digital Inputs Digital Outputs Analog Inputs Cycle the power a few times; if the A failure has occurred and the indicated section of the fault persists replace the control control board may no longer work properly. MODBUS Comms board.
  • Page 62 COMPRESSOR TROUBLESHOOTING Fault Possible Cause Verification Recommended Action Compressor will Faulty control board. No 24vac output on STAGE1 or Replace control board. not start: STAGE2 when compressor should Stage 1 - R410a or be operating. Stage 2 - R134a Faulty run capacitor. Check value with capacitance meter.
  • Page 63 OPERATION TROUBLESHOOTING - HEATING MODE Possible Cause Verification Recommended Action Fault Outdoor tempera- Outdoor EEV is mechani- Verify EEV operation (EEV3 or Replace outdoor EEV if faulty. ture reading is cally faulty and causing EEV4) - see EEV Troubleshooting incorrect by a electromagnetic interfer- section large amount...
  • Page 64 OPERATION TROUBLESHOOTING - HEATING MODE Fault Possible Cause Verification Recommended Action High suction Outdoor unit’s EEV3 or Manually adjusting the outdoor EEV Go to EEV troubleshooting sec- pressure EEV4 stuck open does not affect the superheat or the tion. (may appear to suction pressure.
  • Page 65 OPERATION TROUBLESHOOTING - DEFROST & COOLING MODES Fault Possible Cause Verification Recommended Action High suction pres- Indoor unit’s EEV1 or Manually adjusting the indoor EEV Go to EEV troubleshooting sec- sure EEV2 stuck open does not affect the superheat or the tion.
  • Page 66 OPERATION TROUBLESHOOTING - DEFROST & COOLING MODES Fault Possible Cause Verification Recommended Action Outdoor temper- Outdoor EEV is mechani- Verify EEV operation (EEV3 or Replace outdoor EEV if faulty. ature reading is cally faulty and causing EEV4) - see EEV Troubleshooting incorrect by a electromagnetic interfer- section...
  • Page 67 EEV TROUBLESHOOTING If there is a refrigeration problem such as low charge, plugged filter-dryer, EEV stuck, or any other kind of restriction in the refrigeration system, the apparent EEV position will work its way towards 100% (full open). High superheat is also a symptom.

  • Page 68: Repair Procedures

    Repair Procedures WARNING: WHEN SERVICING THE OUTDOOR UNIT, BE SURE TO TURN OFF POWER TO THE INDOOR UNIT. The outdoor disconnect switch will not cut low voltage power, and damage to the control board will occur if the main heat pump breaker is not turned off during service. Pumpdown Procedure 1.

  • Page 69: Compressor Replacement Procedure

    Compressor Replacement Procedure 1. Pump down the unit as per the Pumpdown Procedure above. If there was a compressor burn out (motor failure), the refrigerant cannot be reused and must be disposed of according to local codes. 2. Disconnect piping. 3.

  • Page 70: Control Board Replacement Procedure

    Control Board Replacement Procedure 1. Turn the power off to the unit. 2. Take a picture of the control board and connectors for reference. The picture in Appendix A may also be helpful. 3. Carefully remove all green terminal strips on the left side, the right side and the bottom of the control board. They pull straight off the board, with no need to disconnect wires from their screw terminals.

  • Page 71: Lcd Interface (Display) Board Replacement Procedure

    LCD Interface (Display) Board Replacement Procedure 1. Turn the power off to the unit. 2. Remove the display board cable connector from the control board. 3. Using a sharp utility knife with a long blade, slice each of the display board standoff heads off, taking care to not damage the lexan cover.

  • Page 72: Model Specific Information

    Model Specific Information Table 24 - Shipping Information - Indoor Unit Table 25 - Shipping Information - Outdoor Unit WEIGHT DIMENSIONS in (cm) WEIGHT DIMENSIONS in (cm) MODEL MODEL lb. (kg) lb. (kg) ATWC-45 ACEC-45 ATWC-55 ACEC-55 ATWC-65 ACEC-65 ATWC-75 ACEC-75 ATWC-80 ACEC-80...

  • Page 73: Pressure Drop Data

    Pressure Drop Data Table 31: Indoor Loop Water 104°F Water 50°F Pressure Water 104°F Water 50°F Drop Data 0.50 0.32 0.57 0.38 0.63 0.44 0.69 0.50 0.76 ATWC- 0.57 ATWC- 0.82 0.63 0.88 0.69 0.95 0.76 1.01 0.82 1.07 0.88 1.14 0.38 0.44...

  • Page 74: Performance Tables

    Performance Tables ATWC-45-HAC-C-1D-* R410a/R134a, 60 Hz OUTDOOR ELECTRICAL INDOOR Outdoor Air Evaporating Heat Absorbed Compressor Input Condensing Liquid Flow Heating MODE Delta T Temperature Temperature (Btu/hr) Current (A) Power (W) Temperature (gpm) (Btu/hr) 0°F Cascade 10°F Cascade 20°F Cascade 30°F Cascade 120°F 40°F...
  • Page 75 Performance Tables ATWC-55-HAC-C-1D-* R410a/R134a, 60 Hz OUTDOOR ELECTRICAL INDOOR Outdoor Air Evaporating Heat Absorbed Compressor Input Condensing Liquid Flow Heating MODE Delta T Temperature Temperature (Btu/hr) Current (A) Power (W) Temperature (gpm) (Btu/hr) 0°F Cascade 10°F Cascade 20°F Cascade 30°F Cascade 120°F 40°F...
  • Page 76 Performance Tables ATWC-65-HAC-C-1D-* R410a/R134a, 60 Hz OUTDOOR ELECTRICAL INDOOR Outdoor Air Evaporating Heat Absorbed Compressor Input Condensing Liquid Flow Heating MODE Delta T Temperature Temperature (Btu/hr) Current (A) Power (W) Temperature (gpm) (Btu/hr) 0°F Cascade 10°F Cascade 20°F Cascade 30°F Cascade 120°F 40°F...
  • Page 77 Performance Tables ATWC-75-HAC-C-1D-* R410a/R134a, 60 Hz OUTDOOR ELECTRICAL INDOOR Outdoor Air Evaporating Heat Absorbed Compressor Input Condensing Liquid Flow Heating MODE Delta T Temperature Temperature (Btu/hr) Current (A) Power (W) Temperature (gpm) (Btu/hr) 0°F Cascade 10°F Cascade 20°F Cascade 30°F Cascade 120°F 40°F...
  • Page 78 Performance Tables ATWC-80-HAC-C-1D-* R410a/R134a, 60 Hz OUTDOOR ELECTRICAL INDOOR Outdoor Air Evaporating Heat Absorbed Compressor Input Condensing Liquid Flow Heating MODE Delta T Temperature Temperature (Btu/hr) Current (A) Power (W) Temperature (gpm) (Btu/hr) 0°F Cascade 10°F Cascade 20°F Cascade 30°F Cascade 120°F 40°F...
  • Page 79 Performance Tables ATWC-100-HAC-C-2D-* R410a/R134a, 60 Hz OUTDOOR ELECTRICAL INDOOR Outdoor Air Evaporating Heat Absorbed Compressor Input Condensing Liquid Flow Heating MODE Delta T Temperature Temperature (Btu/hr) Current (A) Power (W) Temperature (gpm) (Btu/hr) 0°F Cascade 10°F Cascade 20°F Cascade 30°F Cascade 120°F 40°F...

  • Page 80: Electrical Specifications

    Electrical Specifications TABLE 32 - ATWC-Series Electrical Specifications Compressor Compressor Indoor Outdoor Max. Min. Power Supply (R410a) (R134a) Circ. Unit Breaker Wire Code V-ø-Hz Max A Max A Amps Amps Amps 230-1-60 13.5 15.4 35.1 39.0 #8-2* 208-3-60 10.8 25.9 28.6 #8-3* ATWC-...

  • Page 81: Wiring Diagram (208/230-1-60)

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  • Page 82: Electrical Box Layout (208/230-1-60)

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  • Page 83: Wiring Diagram (208-3-60)

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  • Page 84: Electrical Box Layout (208-3-60)

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  • Page 85: Wiring Diagram (460-3-60)

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  • Page 86: Electrical Box Layout (460-3-60)

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  • Page 87: Acec-45/55 Wiring Diagram

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  • Page 88: Acec-65/75/80/100 Wiring Diagram

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  • Page 89: Atwc Refrigeration Circuit - Cascade Heating Mode

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  • Page 91: Atwc Refrigeration Circuit - Warm Weather Heating Mode . 90 Atwc Refrigeration Circuit - Defrost/Cooling Mode

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  • Page 92: Dimensions: Atwc-45/55

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  • Page 93 Dimensions: ATWC-45/55 PRELIMINARY: 24-Sep-2021 Page 93 002536MAN-00...

  • Page 94: Dimensions: Atwc-65

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  • Page 95 Dimensions: ATWC-65 PRELIMINARY: 24-Sep-2021 Page 95 002536MAN-00...

  • Page 96: Dimensions: Atwc-75/80/100

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  • Page 98: Appendix A: Control Board Description

    Appendix A: Gen2 Control Board Description The picture below shows the locations of the connectors and LED indicators of the control board. The control board offers many fea- tures such as short circuit protection on all digital outputs, Real Time Clock with super capacitor for backup power, WiFi capability, relay outputs for plenum heater control (if equipped), USB port, PIC32 microcontroller, etc.

  • Page 99: Table A1 - Control Board Connector Descriptions (Top)

    The tables describe the connections starting with the top of the board and working around the board counter clock-wise. TABLE A1 - Control Board Connector Descriptions (Top) Name Description HPS1/HI1 High Pressure Sensor 1 Mounted in indoor unit, measures R410a discharge pressure. LPS1/LO1 Low Pressure Sensor 1 Mounted in indoor unit, measures R410a suction pressure.

  • Page 100: Table A3 - Control Board Connector Descriptions (Bottom)

    TABLE A3 - Control Board Connector Descriptions (Bottom) Name Description BACnet MS/TP Ground for shield if required. BACnet MS/TP RS-485. BACnet MS/TP RS-485. STAGE1 Compressor Stage 1 Starts / stops the R410a compressor. STAGE2 Compressor Stage 2 Starts / stops the R134a compressor. RV#1 Reversing Valve#1 Unused.

  • Page 101: Table A4 - Control Board Connector Descriptions (Right Side)

    TABLE A4 - Control Board Connector Descriptions (Right Side) Name Description DI_1 Digital Input1 Unused. DI_0 Digital Input0 Unused. Phase Monitor2 Switch or dry contact from R to activate Summer Setback mode. Phase Monitor1 Unused. Aquastat Stage2 Unused. Aquastat Power (24VAC) Optional 24VAC power supply for aquastat used with Signals/Hardwired control.

  • Page 102: Appendix B: Usb Driver Installation

    Appendix B - USB Driver Installation The first step in connecting a Windows laptop computer to the 4. In the window that is displayed, click and hold down the mouse button on the folder name, and drag to your desktop: control board is to install the USB driver.

  • Page 103: Appendix C: Pc App Installation

    Appendix C - PC App Installation The PC App allows detailed interfacing with the control board 4. In the window that is displayed, click and hold down the mouse button on the folder name, and drag to your desktop: using a Windows laptop computer. Any Windows from XP and onwards should be compatible, but Windows 10 (as found on any recent laptop computer) is recommended.

  • Page 104: Appendix D: Updating Firmware

    Appendix D: Updating Firmware The firmware comes as a .ZIP file named: 7. Click on YES. The following message box will appear: MGL GEN2 Bootload Firmware Vxxx.zip where xxx is the version reference, e.g. 400 (version 4.00). This file can be downloaded from www.nordicghp.com, menu For Dealers -->...
  • Page 105 12. Click on Load Hex File. Select the 16. Close the PIC32 program. MGL_GEN2_V400.production.hex (or higher version num- ber) file, which is in the folder you created on the Desktop. 17. WAIT APPROXIMATELY 10 SECONDS. This gives the control board time to reset, initialize and re-connect to the PC USB port.

  • Page 106: Warranty

    Warranty: ATWC-Series COMMERCIAL LIMITED EXPRESS WARRANTY Unless a statement is specifically identified as a warranty, statements made by Maritime Geothermal Ltd. (“MG”) or its representatives relating to MG’s products, whether oral, written or contained in any sales literature, catalogue or agreement, are not express warranties and do not form a part of the basis of the bargain, but are merely MG’s opinion or commendation of MG’s products.

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