Mitsubishi Heavy Industries SRK25QA-S Technical Manual page 40

(6) Service mode (failure mode reading function)
The air conditioner records the past error indication and protection stops (service data). If the
indication of self-diagnosis can't be confirmed, it can be confirmed through service data to
grasp the condition when the error occurs.
(a) Terms
Term
Service mode Service mode refers to indicating service data with the lamp on the display board
through the operation of the indoor controller described in (b).
Service data Refers to the content of past error indication and protection stops of the air conditioner.
The controller of the indoor unit uses nonvolatile memory (the data stored will not
disappear even after the power is cut) to memorize the past error indication and
protection stops of the air conditioner. Service data is composed of self-diagnosis data
and stop data.
Self-diagnosis data Refers to the indication data of causes of past stops of the indoor unit (self-diagnosis
indication). Data of last 5 times can be memorized, and the older data is deleted
automatically. It also includes the temperatures measured by the various sensors (room
temperature, indoor heat exchanger, outdoor liquid pipe, and outdoor temperature
discharge pipe sensors) and information of the remote controller (operation switching
and air flow changes). More detailed data can be confirmed.
Stop data Data of causes of past stops due to protection control, etc. in the air conditioner. If only
stop data is indicated, the system will be restored automatically. (The indication will be
restored automatically after the appliance enters the stop mode normally). Data of last
10 times can be memorized and the older data is deleted automatically. (Important) If
only stop data is indicated, the air conditioner is normal. However, when the same
protection repeats (more than 3 times), it will become the cause of user's complaint.
(b) Indication sequence of service modes
Temporarily switch off the power and wait over one
minute.
Press and hold the back-up switch and insert the cable
into the socket.
No
Does the buzzer on the
indoor unit sound?
Use the remote controller to send signals within one
minute after inserting the cable into the supply.
Count the flashing and going off of the RUN lamp and
(*3)
TIMER lamp , and confirm the content of failure in the
list (see Page 40, 41).
Is there any other data
Make changes according to the remote controller setting
(*4)
list
Description
Begin
Yes
(*2)
No
indication?
Yes
(see Page 41)
-37-
*1: If the buzzer does not sound after
several operations, the back-up
switch may be defective.
*2: The settings of the remote
controller are "Cooling operation",
"Air flow: Me", and "Set
temperature: 21℃).
Restart the appliance more than one
minute after the power is switched off
and the maintenance mode is ended.