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.
2.Verify that the Enable SAT jumper is on.
3.Verify that the Enable SAT and Remote jumper is in the left position.
Wiring an Indoor Air Quality (IAQ) Sensor — An IAQ sensor monitors CO2 levels. The WSHP Open controller uses this information to adjust the
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
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.
2.Install a
3.Verify the the RH/IAQ jumper is set to 0 to
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 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 inches.
2.Strip 1/4 in. of insulation from each wire.
3.Wire the sensor to the controller.
PRE-START-UP
System Checkout — When the installation is complete, follow the system checkout procedure outlined below before starting up the system. Be sure:
1.Voltage is within the utilization range specifications of the unit compressor and fan motor and voltage is balanced for 3 phase units.
2.Fuses, breakers and wire are correct size.
3.Low voltage wiring is complete.
4.Piping and system flushing is complete.
5.Air is purged from closed loop system.
6.System is balanced as required. Monitor if necessary.
7.Isolation valves are open.
8.Water control valves or loop pumps are wired.
9.Condensate line is open and correctly pitched.
10.Transformer switched to lower voltage tap if necessary.
11.Blower rotates freely — shipping support is removed.
12.Blower speed is on correct setting.
13.Air filter is clean and in position.
14.Service/access panels are in place.
15.
16.Air coil is clean.
17.Control
AIR COIL — To obtain maximum performance, clean the air coil before starting the unit. A ten percent solution of dish- washer detergent and water is recommended for both sides of the coil. Rinse thoroughly with water.
PSC (Permanent Split Capacitor) Blower Speed Selection — All water source heat pumps are factory set to deliver rated airflow at nominal static (0.15 in. wg) on medium speed. Where higher static is needed, high speed can be utilized (0.4 to 0.5 in. wg). Low speed will deliver approximately 85% of rated airflow (0.10 in. wg). The PSC blower fan speed can be changed on all units by swapping wires connected to the relay contacts that control the fan. See Fig. 30.
CONNECT THE BLUE WIRE TO:
H FOR HIGH SPEED FAN
M FOR MEDIUM SPEED FAN
L FOR LOW SPEED FAN
BLU
MEDIUM FACTORY SETTING
H M L
FAN MOTOR
Fig. 30 — Blower Speed Selection
The PSC blower fan speed can be changed by moving the blue wire on the fan motor terminal block to the desired speed as shown in Fig. 30. The 50PC units are designed to deliver rated airflow at nominal static (0.15 in. wg) on medium speed (factory setting) and rated airflow at a higher static (0.4 to
0.5in. wg) on high speed for applications where higher static is required. Low speed will deliver approximately 85% of rated airflow at 0.10 in. wg. An optional ‘high static’ blower is avail- able by using the special option code in the model nomenclature.
NOTE: Blower performance is shown in Tables
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