ENGLISH
12.1.2 Alarms for YUTAKI CASCADE CONTROLLER ATW-YCC-(01/02)
Alarm
Code
Retry
Stop
Code
Origin
Detail of Abnormality
Main Factors
03
-
Communication
Lost communication with all slave YUTAKI Units
Loose, disconnected, broken or
short-circuited connector
15
-
Indoor
Water Circuit 2 thermistor abnormally (THMwo2)
Loose, disconnected, broken or
short-circuited connector
16
-
Indoor
Water DHW thermistor abnormally (THMdhwt)
Loose, disconnected, broken or
short-circuited connector
17
-
Indoor
Auxiliary sensor 2 thermistor abnormally (THMaux2)
Loose, disconnected, broken or
short-circuited connector
18
-
Indoor
Auxiliary sensor 1 thermistor abnormally (THMaux1)
Loose, disconnected, broken or
short-circuited connector
25
-
Indoor
Auxiliary sensor 3 thermistor abnormally (THMaux3)
Loose, disconnected, broken or
short-circuited connector
40
-
Indoor
Incorrect LCD setting
Current LCD configuration does not
allow proper operation
60
-
Slave unit
All slave units are in alarm state or there is no communication.
Alarm release, when issue disappears
Slave unit alarm
73
Indoor
Mixing over-temperature limit protection for Mixed circuit.
Circuit 2 supply temperature >
Target tempe offset
74
P74
Indoor
Unit over-temperature limit protection
Two > Tmax +5K
75
-
Indoor
Freeze Protection by Cold water inlet, outlet temperature detection
77
-
Indoor-LCD
Receiver Communication failure
No Opentherm/Hlink
communication for a continuous
period of 10 minutes.
78
Indoor-LCD
RF Communication failure
There is no communication for 1
hour with on or two RF receives
which are bound to the RF-Bridge.
80
-
Indoor
LCD H-link RCS transmission error
No H-link communication for a
continuous period of 1 minute
between Indoor and LCD User
control by connection wiring
(breaking, wiring error, etc.)
LCD
(If no H-LINK RCS has no power)
21X
-
Slave unit
Module X is in alarm state. X stands for the module number. A
module is determined to be in alarm state in case that module is in
alarm or YUTAKI CASCADE CONTROLLER lost communication
with specific module.
Slave unit alarm
12.1.3 Alarms for Outdoor units
Code
number
Category
Type of abnormality
Main cause
2
Outdoor unit
Activation of protection device
(high pressure cut)
Activation of PSH, locked motor, abnormal operation in the power
supply phase.
Failure of fan motor, drain discharge, PCB, relay, float switch
activated.
(Pipe clogging, excessive refrigerant, innert gas mixing, fan motor
locking at cooling operation)
3
Transmission
Abnormal transmission between outdoor and
indoor units
Incorrect wiring. Loose terminals, Failure of PCB. Tripping of fuse.
Power supply OFF.
4
Abnormal transmission between inverter PCB
and RASC unit PCB
Transmission failure between inverter PCBs. (Loose Connector,
Wire Breaking, Blowout of Fuse).
5
Power supply
Reception of abnormal operation code for
detection of power source phase
Power source with abnormal wave pattern. Main power supply
phase is reversely connected or one phase is not connected.
6
Voltage
Excessively low voltage or excessively high
voltage for the inverter
Voltage drop in power supply. Incorrect wiring or insufficient
capacity of power supply wiring.
TROUBLESHOOTING
PMML0575 rev.2 - 03/2022
317
