Nordic ATWC Series, Installation And Service Manual, Page: 99 / 106

PRELIMINARY: 24-Sep-2021 Page 99 002536MAN-00
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.
EEV1 Local EEV Unused (all unipolar EEV’s controlled through MODBUS boards)
TS1 Suction Line Temperature 1 Mounted to R410a indoor unit common suction line.
EEV2 Remote EEV Unused (all unipolar EEV’s controlled through MODBUS boards)
TS2 Suction Line Temperature 2 Mounted to R134a indoor unit common suction line.
HPS2/HI2 High Pressure Sensor 2 Mounted in indoor unit, measures R134a discharge pressure.
LPS2/LO2 Low Pressure Sensor 2 Mounted in indoor unit, measures R134a suction pressure.
HTS/ODTS Outdoor Temperature Unused (outdoor temperature acquired through outdoor MODBUS board)
CTS Auto Calibration Resistor in connector for auto-calibration reference (32°F—0°C).
I_IN Indoor Loop IN Mounted to pipe inside unit.
I_OUT Indoor Loop OUT Mounted to pipe inside unit.
O_IN Outdoor Loop IN Unused.
O_OUT Outdoor Loop OUT Unused.
TABLE A2 - Control Board Connector Descriptions (Left Side)
Name Description
PWM_IN Signal for PWM IN Unused.
IN_SPARE Spare digital input Switch or dry contact from 12VDC to disable unit (also COM_IN to GND).
COM_IN Common for PWM IN Jumper to GND for disable functionality.
PWM4 PWM / 0-10VDC output Unused.
PWM3 PWM / 0-10VDC output Unused.
PWM2 PWM / 0-10VDC output Unused.
PWM1 PWM / 0-10VDC output Unused (PWM sent to outdoor fan through outdoor MODBUS board).
GND Ground Jumper to COM_IN for disable functionality.
HZC Hot Zone Circulator Unused.
CZC Cold Zone Circulator Unused.
ICR Internal Circulator Relay Operates the Indoor Circulator.
DO_3 AUX_ONLY Output OFF when auxiliary to be run without compressor; operates H1-H2.
DO_2 HYD_AUX ON when hydronic auxiliary ON (Setpoint Control only).
DO_1 Digital output Unused.
DO_0 Digital output Unused.
LC Loop common (ground) Ground.
L6 Loop6 Unused.
L5 Loop5 Unused.
L4 NOT_HYD_AUX Output OFF when auxiliary heat required; operates D1-D2 dry contacts.
L3 TWO_TANK_3_WAY Energizes 3-way valve to direct flow to cold tank when using HTS/CTS with 2 tanks
L2 Loop2 Unused.
L1 Loop1 ON when outdoor fan is operating.
C(SH) Soaker Hose common Ground for SH pin.
SH Soaker Hose Defrost indicator: ON when unit in defrost mode.