Water Requirement; Water Flow Switch Installation - A.O. Smith CAHP-MC-38 Installation, Operation And Maintenance Instructions

1.14. Water Requirement

Please check the installation location water hardness data before formal installation. The heat pump
units could only be operated with water which has hardness less than 200ppm. A water treatment
device is requested if the water hardness is higher than 200ppm. Please do not use the untreated water
from river, lake, or underground directly.

1.15. Water Flow Switch Installation

Please install the water flow switch (accessory part) on the outlet pipeline from each heat pump unit to
the tank. The water flow switch should be installed at a location which has straight pipe at both inlet
and outlet side. The minimum straight pipe length needs to be longer than 5 times of the pipe
diameter.
Picture 5.6
Please wire the water flow switch with reference to the heat pump wiring diagram and the yellow line
should be connected to the "D16" terminal and the red line should be connected to one of the "GND"
terminal.
The water flow switch could be adjusted based on the actual conditions. Correct flow switch setting
should create a flow rate at 6.5CMH (turn off if the water flow rate is lower than 4CMH and turn on if
the water flow rate is higher than 5.5CMH). Please contact the qualified service personnel for detailed
ajustement methodology.