Daikin CMSQ200A7W1B Service Manual page 167

Troubleshooting by Indication on the Remote Controller
Troubleshooting
156
Be sure to turn off power switch before connect or disconnect connector,
Caution or parts damage may be occurred.
Is the stop
valve open?
Mount a pressure gauge on the low-pressure service port.
Connect the Service Checker.
Reset the operation using the remote controller, and then
restart the operation.
Are the
characteristics of the
low pressure sensor
normal?
(See *1.)
Is the
pressure detected
with the PC board
normal?
(See *2.)
· The low pressure sensor is normal, and the pressure
detected with the PC board is also normal.
· The low pressure has really become low.
Referring to information on page 228, remove the
CHECK 4
causes by which the low pressure has become low.
*1: Make a comparison between the voltage of the pressure sensor and that read by the
pressure gauge.
(As to the voltage of the pressure sensor, make measurement of voltage at the connector,
and then convert it to pressure according to information on page 249.)
*2: Make a comparison between the low pressure value checked with the Service Checker
and the voltage of the pressure sensor (see *1).
*3: Make measurement of voltage of the pressure sensor.
Micro controller
A/D input
Make measurement of DC voltage between these wires.
NO
YES
NO
YES
NO
YES
+5V
Connector for low pressure sensor
(Blue)
(4)
(3)
(2)
(1)
SiBE28-805
Open the stop valve.
Replace the low pressure sensor.
Replace the main PC board.
Red
Black
Low
pressure
White sensor
Troubleshooting