Carrier 50PSH, PSD006-070, PSV Operate ECM Interface Board, A50-8443, Rnet Wiring, Wire Terminal

	OUTER JACKET
.25 IN.	a50-8443
	INNER INSULATION

Fig. 32 — Rnet Cable Wire

3.Wire each terminal on the sensor to the same terminal on the controller. See Fig. 15-25. Table 10 shows the recom- mended Rnet wiring scheme.

Table 10 — Rnet Wiring

Gage) cable should be used. If the cable will be greater than 100 ft, a shield 22 AWG cable should be used. The cable should have a maximum length of 500 ft.

To wire the RH sensor to the controller:

1.Strip the outer jacket from the cable for at least 4 in.

2.Strip 1/4 in. of insulation from each wire.

3.Wire the sensor to the controller.

Step 10 — Operate ECM Interface Board —

The ECM fan is controlled by an interface board that converts thermostat inputs and field selectable cfm settings to signals used by the ECM (electronically commutated motor) controller. See Fig. 33.

WIRE	TERMINAL
Red	+12-v
Black	.Rnet–
White	Rnet+

1/4" SPADE

CONNECTIONS

TO COMPLETE C OR DELUXE D BOARD

R	G	Y1	Y2	O	W
	G	G	G	G	R

THERMOSTAT INPUT LEDS

Green Gnd

NOTE: The wire should be connected to the terminal shown.

Wiring a Supply Air Temperature (SAT) Sensor — The SAT sensor is required for reheat applications.

If the cable used to wire the SAT sensor to the controller will be less than 100 ft, an unshielded 22 AWG (American Wire Gage) cable should be used. If the cable will be greater than 100 ft, a shield 22 AWG cable should be used. The cable should have a maximum length of 500 ft.

To wire the SAT sensor to the controller:

1.Wire the sensor to the controller. See Fig. 15-25.

2.Verify that the Enable SAT jumper is on.

3.Verify that the Enable SAT and Remote jumper is in the left position.

THERMOSTAT CONNECTIONS

DEHUMIDIFICATION

LED

TB1 C Y2 Y1 G O W C R DH AL1 A A AL1

				CFM	Y
G		SW2 SW3 SW4 SW5 SW6 SW7 SW8 SW9	SW1
DEHUM	OFF ON			S1	J1

CFM COUNTER

1 FLASH PER 100 CFM

ECM MOTOR

LOW VOLTAGE

CONNECTOR

A50-7739

Wiring an Indoor Air Quality (IAQ) Sensor — An IAQ sensor monitors CO2 levels. The WSHP Open controller uses this information to adjust the outside-air dampers to provide proper ventilation. An IAQ sensor can be wall-mounted or mounted in a return air duct. (Duct installation requires an aspi- rator box assembly.)

The sensor has a range of 0 to 2000 ppm and a linear 4 to

20 mA output. This is converted to 1 to 5 vdc by a 250-ohm, 1/4 watt, 2% tolerance resistor connected across the zone con- troller’s IAQ input terminals.

NOTE: Do not use a relative humidity sensor and CO2 sensor on the same zone controller if both sensors are powered off the board. If sensors are externally powered, both sensors may be used on the same zone controller.

If the cable used to wire the IAQ sensor to the controller will be less than 100 ft, an unshielded 22 AWG (American Wire Gage) cable should be used. If the cable will be greater than 100 ft, a shield 22 AWG cable should be used. The cable should have a maximum length of 500 ft.

To wire the IAQ sensor to the controller:

1.Wire the sensor to the controller. See Fig. 15-25.

2.Install a field-supplied 250-ohm, 1/4 watt, 2% tolerance resistor across the controller’s RH/IAQ and Gnd terminals.

3.Verify the the RH/IAQ jumper is set to 0 to 5 vdc.

Wiring a Relative Humidity (RH) Sensor — The RH sensor is used for zone humidity control (dehumidification) if the WSHP unit has a dehumidification device. If not, the sensor only monitors humidity.

NOTE: Do not use a relative humidity sensor and CO2 sensor on the same zone controller if both sensors are powered off the board. If sensors are externally powered, both sensors may be used on the same zone controller.

If the cable used to wire the RH sensor to the controller will be less than 100 ft, an unshielded 22 AWG (American Wire

FAN SPEED SELECTION DIP SWITCH

Fig. 33 — ECM Interface Board Physical Layout

NOTE: Power must be off to the unit for at least three seconds before the ECM will recognize a speed change. The motor will recognize a change in the CFM Adjust or Dehumidification mode settings while the unit is powered.

There are four different airflow settings from lowest airflow rate (speed tap 1) to the highest airflow rate (speed tap 4). Table 11 indicates settings for both versions of the ECM inter- face board, followed by detailed information for each setting.

CAUTION

When the disconnect switch is closed, high voltage is present in some areas of the electrical panel. Exercise cau- tion when working with energized equipment. Failure to heed this safety precaution could lead to personal injury.

COOLING — The cooling setting determines the cooling (normal) cfm for all units with ECM motor. Cooling (normal) setting is used when the unit is not in Dehumidification mode. Tap 1 is the lowest cfm setting, while tap 4 is the highest cfm setting. To avoid air coil freeze-up, tap 1 may not be used if the Dehumidification mode is selected. See Table 11.

HEATING — The heating setting determines the heating cfm for 50PSH, PSV, PSD units. Tap 1 is the lowest cfm setting, while tap 4 is the highest cfm setting. See Table 11.

CFM ADJUST — The CFM Adjust setting allows four selec- tions. The NORM setting is the factory default position. The + or – settings adjust the airflow by ±15%. The + or – settings are used to “fine tune” airflow adjustments. The TEST setting runs the ECM at 70% torque, which causes the motor to operate like a standard PSC motor, and disables the cfm counter. See Tables 11-13 for ECM and PSC blower motors performance data.

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