Nordic ATWC Series, Installation And Service Manual, Page: 56 / 106

PRELIMINARY: 24-Sep-2021 Page 56 002536MAN-00
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. Follow the instructions below in the Preparation section to enable the compressor.
The LCD interface will show the outdoor temperature, suction pressures, discharge pressures, superheats, EEV positions,
and water in/out temperatures.
Preparation:
1. Turn the power on to the heat pump. All LED’s on the control board should turn on, the LCD interface should say “ MGT GEN2
VERx.xx ” on line 1 and “ Zeroing EEV’s ” on line 2. You should be able to hear the EEV’s moving (a clicking sound).
2. Measure the following voltages on the power block and record them on the startup sheet: L1-L2, L2-L3, L1-L3.
3. Connect a USB cable between the USB connector on the board and a laptop computer (if available).
4. Select the desired Control Source HYD via the PC APP Configuration Page or via the LCD display Configuration Menu.
5. Enable the system either with the Configuration Page System Enable/Disable button or via the LCD display.
(IMPORTANT NOTE: compressor(s) may start on their own if Setpoint Control is selected).
Heating Mode:
1. Activate Stage 1. The outdoor EEV(s) will begin to open and the compressor(s) will start, as will the circulator pumps.
Note that the system will start in cascade mode if the outdoor temperature is below ~50°F (meaning both refrigeration
circuits will be active), and in R134a mode only if outdoor temperature is warmer.
2. Check the PC APP or LCD interface. The suction and discharge pressures will vary based on the outdoor temperature and the
indoor loop temperature, and in warm weather only circuit 2 (R134a) will be active.
3. Monitor the unit via the PC APP or LCD while the unit runs, and record the following after 10 minutes of run time:
1. R410a suction & discharge pressures (only active if in cascade mode)
2. R134a suction & discharge pressures
3. Indoor Loop In (Hot In) temperature
4. Indoor Loop Out (Hot Out) temperature
5. Indoor Delta T (should be 8-12°F / 4-6°C )
6. Indoor flow (if available)
7. Outdoor air temperature
8. Compressor 1 & 2 L1(C) current (black wire, place meter between electrical box and compressor)
4. Adjust the control setpoints to the desired buffer tank temperature and let the unit run through a cycle. Record the setpoint
and R134a discharge pressure just before the unit shuts off.
Cooling Mode:
1. Set the unit to cooling mode and adjust the cooling setpoints to activate stage 1.
Note that in cooling mode, only the R134a circuit will be active.
2. Monitoring the unit via the PC APP or LCD display while the unit runs, record the following after 10 minutes of run time:
1. R134a suction pressure
2. R134a discharge pressure
3. Indoor Loop In temperature
4. Indoor Loop Out temperature
5. Indoor Delta T
6. Outdoor air temperature
3. Adjust the cooling setpoints to the desired tank temperature, and allow the unit to run through a cycle. Record the
setpoint and the suction pressure when the unit shuts off.
Final Inspection:
1. Turn the power off to the unit and remove all test equipment.
2. Install the electrical box cover and the access panel on the heat pump. Install the service port caps securely to prevent
refrigerant loss.
3. Do a final check for leaks in the indoor loop piping and ensure the area is clean.
4. Turn the power on to the unit. Set the Setpoints Control (or aquastat) to the final settings and record the values.
Startup Record:
1. The installer should sign and date the Startup Record and have the startup witness or appropriate site personnel sign as well.
The startup personnel should leave the Startup Record at the site, retain a copy for filing, and send a copy to Maritime Geother-
mal Ltd. for warranty registration.