Mitsubishi Electric CITY MULTI PUHY-P200YEM-A Service Handbook page 82

Connector connection specifications on the pressure sensor body side.
The connector's pin numbers on the pressure sensor body side differ from the pin numbers on the main circuit board
side.
Sensor Body Side
Vcc
Vout
GND
(2) Solenoid Valve (SV1, 3, 4 for PU(H)Y-P200·250·315, SV1 for PU(H)Y-200·250·315)
Check if the control board's output signals and the operation of the solenoid valves match.
Setting the self-diagnosis switch (SW1) as shown in the figure below causes the ON signal of each relay to be output to
the LED's.
Each LED shows whether the relays for the following parts are ON or OFF. When a LED lights up, it indicates that the
relay is ON.
SW1
1 2 3 4 5 6 7 8 9 10
ON
1 2 3 4 5 6 7 8 9 10
ON
1) In the case of SV1 (Bypass Valve)
(a) When the compressor starts, SV1 is ON for 4 minutes, check operation by whether the solenoid valve is emitting
an operating noise.
(b) Changes in the oper
bypass circuit and the sound of the refrigerant.
(c) SV1 goes on in accordance with the rise in high pressure in the cooling and heating mode, check operation
by LED display and the operating noise emitted by the solenoid valve.
2) SV3, 4 (Control of heat exchanger capacity)
(a) Operations can be confirmed by LED display and operating sound of solenoid valve, because one or more of
SV3, 4 are turned on depending on conditions during cooling-only operations.
3) In the case of 21S4 (Multi-directional valve)
Multi-directional valve features
When power is OFF: Used as a conductor for the cooling circuit between the oil separator outlet and heat
When power is ON : Used as a conductor for the heating circuit between the oil separator and gas-ball valve, and
It is possible to determine whether the unit is functioning properly by checking from which point to which point the
current is flowing by monitoring the LED display, or by checking the temperature at the time at both the inlet and
outlet of the multi-directional valve. Do not to check the temperature of the oil separator by direct contact due to the
high temperature of the piping.
Do not apply excessive external impact, as the valve will not function properly if the outer wall is deformed.
(3) Outdoor unit fan
· The outdoor unit fan is phase control and controls the number of fan rotations. Confirm the number of rotations while
monitoring the output status of the phase control output at the LED. The fan rotates at approximately 600rpm at full
speed.
· Refer to the outdoor unit control section for details on fan control.
The fan operates at 100% for 5 seconds and then alternates between high and low pressure control.
Turn the self-diagnosis switch ON to
control output status at the LED display.
There are times when the AK does not go as high as 100 when in night mode etc.
MAIN Board Side
Pin 1 Pin 3
Pin 2 Pin 2
Pin 3 Pin 1
1 2
Comp Comp
operation operation
SV1
ating condition by solenoid valve operation can be confirmed by the temperature of the
exchanger, and the gas-ball valve (BV1) and accumulator.
the heat exchanger and accumulator.
1 2 3 4 5 6 7 8 9 10
ON
LED
3 4 5
52C1
, the phase
- 81 -
6 7 8
lights
for normal
operation
SV3 SV4
LED Display
0
Stop Full speed
Fan
100