Mitsubishi Heavy Industries SRK100VNXPZSX Technical Manual page 89

SRK series
1) Cautions 1) Cautions
a) If you are disassembling and checking an air-conditioner, be sure to turn off the power before beginning. a) If you are disassembling and checking an air-conditioner, be sure to turn off the power before beginning.
When working on indoor units, let the unit sit for about 1 minute after turning off the power before you begin work. When working on indoor units, let the unit sit for about 1 minute after turning off the power before you begin work.
b) When taking out printed circuit boards, be sure to do so without exerting force on the circuit boards or package components. b) When taking out printed circuit boards, be sure to do so without exerting force on the circuit boards or package components.
c) When disconnecting and connecting connectors, take hold of the connector housing and do not pull on the lead wires. c) When disconnecting and connecting connectors, take hold of the connector housing and do not pull on the lead wires.
2) Items to check before troubleshooting 2) Items to check before troubleshooting
a) Is the air-conditioner running? Is it displaying any self-diagnosis information? a) Is the air-conditioner running? Is it displaying any self-diagnosis information?
b) Is a power source with the correct voltage connected? b) Is a power source with the correct voltage connected?
c) Are the control lines connecting the indoor and outdoor units wired correctly and connected securely? c) Are the control lines connecting the indoor and outdoor units wired correctly and connected securely?
d) Is the outdoor unit's service valve open? d) Is the outdoor unit's service valve open?
3) Troubleshooting procedure (If the air-conditioner does not run at all) 3) Troubleshooting procedure (If the air-conditioner does not run at all)
If the air-conditioner does not run at all, diagnose the trouble using the following troubleshooting procedure. If the air-conditioner does not run at all, diagnose the trouble using the following troubleshooting procedure.
When all the following conditions are satisfied, we say that the air-conditioner will not run at all. When all the following conditions are satisfied, we say that the air-conditioner will not run at all.
Important Important
a) The RUN light does not light up. a) The RUN light does not light up.
b) The f laps do not open. b) The f laps do not open.
c) The indoor unit fan motors do not run. c) The indoor unit fan motors do not run.
d) The self-diagnosis display does not function. d) The self-diagnosis display does not function.
Troubleshooting procedure (If the air-conditioner does not run at all) Troubleshooting procedure (If the air-conditioner does not run at all)
Is the correct voltage Is the correct voltage
connected for the power connected for the power
source? source?
With the power off, do With the power off, do
the ßaps open manually, the ßaps open manually,
then close again when then close again when
the power is turned on? the power is turned on?
Replace the indoor printed Replace the indoor printed
circuit board and perform an circuit board and perform an
operation check. operation check.
Make sure the correct volt-
NO NO
age is connected, then per-
form an operation check.
YES YES
NO NO
YES YES
Proceed to the indoor printed
circuit board check.
Make sure the correct volt-
age is connected, then per-
form an operation check.
Is the current fuse on the in- Is the current fuse on the in-
, ,
door unit door unit s board broken? s board broken?
NO NO
Proceed to the indoor printed
circuit board check.
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'17 • PAC-T-257
* If the voltage is correct, it will be * If the voltage is correct, it will be
within the following voltage range. within the following voltage range.
AC198 - 264V AC198 - 264V
YES YES
If the package components If the package components
are not damaged, replace are not damaged, replace
the fuse and perform an op- the fuse and perform an op-
eration check again. eration check again.