Hitachi UTOPIA RAS-4HVRP2E - Page 282

10 Troubleshooting
Troubleshooting procedure
SMGB0136 rev.0 - 07/2021
280
Alarm code
31
Incorrect Capacity Setting of Outdoor Unit and Indoor Unit
• Thealarmcodeisashedonthe7-segmentdisplayoftheoutdoorunit.
• The alarm code is displayed on the wired controller of the indoor unit.
ThisalarmcodeisdisplayedwhenanundenedsettingissettoDSW3(forcapacityandpowersupplysetting)onthe
service board or O.U.PCB (4~6HP).
This alarm code is displayed when the total indoor unit capacity is outside the range of connectable indoor unit capacity
ratio.
Connectable Indoor Unit Capacity
Outdoor Unit Model
Connectable Indoor Unit Capacity Ratio
Minimum Maximum
4HP ~ 6HP 45% 150%
Phenomenon
Cause
Check Item
Action (Turn OFF
Main Switch)
No
No
No
Yes
Yes
Yes
Is DSW3 of outdoor unit set
incorrectly?
Is DSW3 on Indoor Unit PCB set
incorrectly?
Are the setting of DSW4 and
RSW1 on Outdoor Unit and
setting of DSW5 and RSW2 on
Indoor Unit PCB totally same in a
refrigerant system?
Total Indoor Unit capacity is wrong
Outdoor Unit: DSW4, RSW1
Indoor Unit: DSW5, RSW2
Set them correctly
Set capacity correctly
Set capacity of Indoor Unit PCB
Incorrect Capacity Setting of Indoor Unit
Incorrect Capacity Setting of Outdoor Unit
Total Indoor Unit Capacity Connected to Outdoor Unit is Beyond
Permissible Range
Refrigerant System Setting of Outdoor Unit and Indoor Unit is Different
Check combination of Indoor
Units and capacity setting of
Indoor Unit PCB
Check capacity setting of
Outdoor Unit
Check Outdoor Unit model by
calculating total Indoor Units
capacity
Check refrigerant system setting
of Outdoor Unit and Indoor Unit
PCB
Correctly set DIP switch, DSW3
Correctly set DIP switch, DSW3
Ensure the total Indoor Unit
capacity
Set them correctly