- WattMaster Water Source Heat Pump Operations Manual

WattMaster WHP Section 4
4-10 Start-Up and Troubleshooting
3.2 Loop Controller Inputs & Outputs
3.2.1 Analog Inputs
AIN1 - Return Water Temp - This input accepts a two wire 10K Type III ther-
mistor temperature sensor. The sensor measures 10,000 Ohms @ 77°F. The re-
sistance drops as the temperature increases. The sensor is connected between this
terminal and the GND terminal.
AIN2 - Supply Water Temp - This input accepts a two wire 10K Type III ther-
mistor temperature sensor. The sensor measures 10,000 Ohms @ 77°F. The re-
sistance drops as the temperature increases. The sensor is connected between this
terminal and the GND terminal.
AIN3 – Proof of Flow/Loop Pressure - This input accepts a differential pressure
contact closure for proof of flow or a 0-50 PSI (0-5VDC) pressure transducer sig-
nal.
AIN4 - Outdoor Air Temp - The OA temperature is used to determine if pumps
should be turned on during off periods, to prevent freezing. When the OA tem-
perature is below 40° F, the pumps will be turned on.
AIN5 - Manual Reset Input - Used to restart equipment after alarm condition
has occurred. When this input is shorted to GND by a momentary pushbutton, a
signal to restart is sent.
AIN7 – Phase Loss – If a phase monitor is being used, a normally open contact is
connected here. When a loss of phase is detected, this contact closes shutting
down the Loop Controller.
GND - Common return wire. This point is tied to ground on the Loop Controller.
3.2.2 Analog Output
This connector carries a 0-10 volt control signal for the following items:
AOUT1- Pump VFD Signal - If you have selected the variable speed pump op-
tion this output signal is used to control the loop pressure.
AOUT2 - Proportional Heat Signal - This output may be used when a modulat-
ing signal is required to control heat addition temperature.
GND - Common return wire, this point is tied to GND on the Loop Controller.