Noise - Mitsubishi Electric Mr.SLIM PUH-P1VGAA Technical & Service Manual

<Output pulse signal and the valve operation>
Output
(Phase)
1
ON OFF
{1
ON ON
{2
OFF ON
{3
OFF OFF
{4
Linear expansion valve operation
Close
A
E
B
Extra tightning (32 pulse)
Trouble shooting
Problem
Operation circuit Remove the connector from the controller board and connect diagnostic
failure of the micro LEDs.
processor.
Pulse signal will be sent out for 10 seconds as soon as the main switch is
turn on. If there is LED with lights on or lights off, it means the operation
circuit is abnormal.
Linear expansion
Motor will idle and make ticking noise when motor is operated while the linear
valve mechanism is
expansion valve is locked.
locked.
This ticking sound is the sign of the abnormality.
Measure the resistance between the each coil (red-white, red-orange,
Short or breakage of
brown-yellow, brown-blue) using a tester. It is normal if the resistance
the motor coil of the
is in the range of 150' ±10%.
linear expansion valve.
1 Check improperly connected connector terminals and the wire colors.
Wrong connection of
2 Remove the connector on the controller board side and check electrical
the connector or
contact failure.
Output
2 3 4
OFF ON
OFF OFF
ON OFF
ON ON
C
D
Open
2000 pulse
Opening a valve
all the way
Pulse number
1k" LED
conductance
Closing a valve : 1 2
Opening a valve : 4 3
The output pulse shifts in above order.
1. When linear expansion valve operation stops, all output phase
become OFF.
2. At phase interruption or when phase does not shift in order,
motor does not rotate smoothly and motor will locks and vibrates.
When the switch is turned on, 2200 pulse closing valve signal
will be send till it goes to
tion.
When the valve move smoothly, there is no noise or vibration
occurring from the linear expansion valve : however, when the
pulse number moves from
more noise can be heard than normal situation.
Noise can be detected by placing the ear against the screw dri-
ver handle while putting the screw driver to the linear expansion
valve.
Check point
6
5
4
3
2
1
47
3 4 1
2 1 4
point in order to define the valve posi-
A
to or when the valve is locked,
E A
Corrective measure
Exchange the indoor
controller board at drive
circuit failure.
Exchange the linear
expansion vale.
Exchange the linear
expansion valve.
Disconnect the connector
at the controller board,
then check the continuity.