Panasonic U-72MF2U9 Installation Instructions Manual page 59

Wired remote
control display
Abnormal device function
H21
H31
• The parentheses of << >> used in the table of alarm display does not affect anything the operation of other indoor units.
• The parentheses of < > used in the table of alarm display implies that there are two cases: according to the content of the
symptom, some affect the operation of other indoor units and others do not affect anything.
Alarm messages displayed on system controller
Error in transmitting serial
communication signal
Serial
communication
errors
Error in receiving serial
Mis-setting
communication signal
Activation of
Protective device of sub indoor
protective
unit in group control is activated.
device
NOTE
1. Alarm messages in << >> do not affect other indoor unit operations.
2. Alarm messages in < > sometimes affect other indoor unit operations depending on the fault.
ATTENTION!
Adjustment of terminating resistance (pin) is necessary.
Communication failure will occur unless adjustment is made correctly.
• Terminating resistance (pin) is mounted on outdoor unit control P.C. board.
• When connecting central controller, interface or peripheral equipment, adjustment of terminating resistance (pin) is necessary.
Although the connection is not made, confirmation is necessary for VRF systems.
• In the case of a refrigerant system, the terminating resistance (pin) for this inter-unit control wiring (S-LINK wiring) is one
location (See the section "7-5. Auto Address Setting").
For 2 or more refrigerant systems, 2 locations should be valid ("SHORT" for VRF systems at shipment). See the section
"7-5. Auto Address Setting".
In order to make 2 locations valid, let the terminating resistance (pin) of the nearest outdoor unit and the farthest outdoor unit be
valid (SHORT side) from the location of central controller.
In other refrigerant systems excepting 2 locations described above, make them invalid (OPEN side).
It is prohibited making more than 3 locations of terminating resistance valid.
• Since the use of linking the sub outdoor units of VRF systems is not connected to the inter-unit control wiring, it is not necessary
to make the terminating resistance invalid "OPEN side".
Make final confirmation regarding the central controller or interface & inter-unit control wiring (S-LINK wiring) connected to the
peripheral equipment.
Measure the line resistance with a tester and check whether the values are in the range of 30Ω - 120Ω.
If the resistance values are out of range, check again the terminating resistance.
Nevertheless, if the values are out of range, the problem comes from wiring.
• Is the connection properly made?
• Are there any scratches or damages on the coated surface?
• Measure the line, between wires and ground with the 500V megger (insulation
resistance meter) and check the values are over 100MΩ.
• When measuring, be sure to remove both edges of the wire from the terminal board.
If not removed, it will be damaged.
• If the line resistance is within 100MΩ, newly carry out the wiring work.
Detected contents
HIC for 2nd compressor has failure. Overcurrent or overheat of HIC.
HIC for 1st compressor has failure. Overcurrent or overheat of HIC.
Indoor or main outdoor unit is not operating correctly.
Mis-wiring of control wiring between indoor unit, main outdoor unit and
system controller.
Indoor or main outdoor unit is not operating correctly.
Mis-wiring of control wiring between indoor unit, main outdoor unit and
system controller.
CN1 is not connected properly.
When using wireless remote controller or system controller, in order to
check the alarm message in detail, connect wired remote controller to
indoor unit temporarily.
59
C05
C06
P30
Megger
Line
(Wire)
(Wire)
Between wires and ground
(Wire)
(Wire)
(Ground)