INSTALLATION INSTRUCTIONS
Step 3 - Installation of the Outdoor Unit (Cont.)
Models:
4U36MS2VHB
3U24EH2VHA
3U24MS2VHB
2U20EH2VHA
4U36EH2VHA
Models:
2U18MS2VHB
D. Wiring Error Check
• This unit is capable of automatically checking for wiring errors
between the indoor and outdoor units.
• To enter the wiring error check test, remove power to unit,
place all 4 DIP switches on the test board in the "ON" position
(illustration 6). Reapply power to the unit. The system will now
enter "Wiring Error Check"
• The numeric display will initialize and begin to alternate
between the compressor working frequency (a number
representing the Hz value) and "CH" (Checking).
• As the check is being performed, all units that are properly
connected will be indicated by the corresponding LED for that
circuit being lit constantly. (LED 1 = piping circuit A, LED 2 =
piping circuit B, ...)
• After the check has completed, if all wiring is correct,
the numeric display will indicate "0" and the single LEDs
representing the individual circuits for the connected indoor
units will be lit constantly.
• If there are any miswired units, the numeric display will flash
"EC" (error connection), and th corresponding LED for the
miswired circuit will flash. Check and correct the wiring as
needed.
14
Power Wiring
To Service Disconnect
230 Volt Supply. 1 to L1, 2 to L2.
Indoor unit A
Strain Relief
Brackets
Indoor unit B
Indoor unit 1
Indoor unit 2
Sugested Colors
Control Wiring
4 Wire - 14 AWG
Diagnostic and Control
Only on 3U24MS*,
Only on 3U24MS*,
Only on FlexFit 4U
Only on FlexFit 3U & 4U
4U36MS*, 2U20EH*,
4U36MS*, 2U20EH*,
and Arctic 2U & 3U
and Arctic 2U & 3U
Outdoor unit
3U24EH*, and 4U36EH*
3U24EH*, and 4U36EH*
3
4
( C
)
( C
)
1 )
(N
(L
)
3
1 )
(N
(L
)
3
1 )
(N
(L
)
3
2
2
2
A
B
C
Indoor unit C
Control Wiring
4 Wire - 14 AWG
Stranded
Outdoor unit
1
=White
=Black
2
( C
)
1 )
( N
2
(L
)
3
1 )
( N
3
=Red
=Green
Stranded
Strain Relief
Brackets
• Refer to the chart shown below. (Table 2)
• When the test is complete, remove power to the system and
return the 4 DIP switches to the OFF position. Reapply power
to the the system. The test is complete.
• If the self-check is not possible, check the indoor unit wiring
and piping in the usual manner.
Only on 3U24MS
Only on FlexFit 3U
)
)
1
(N
2
(L
3
4
( C
)
( C
)
1 )
(N
(L
)
3
2
D
Indoor unit D
Sugested Colors
1
=White
2
=Black
3
=Red
=Green
( N
)
(L
)
1
2
( C
)
2
(L
)
3
Power Wiring
To Service Disconnect
230 Volt Supply. 1 to L1, 2 to L2.
31-5000001 Rev. 6