Page 64
MS8C / MS8H (208-230V)
Continued — 18 - 24 kBtu System Status or Error Codes — Indoor Character Display and Outdoor LEDs
Indoor
Unit
Display
Outdoor Unit LED Status
Error Description
System Status
Troubleshooting for Possible
Causes
This unit has three display
status indicators
o
OFF
n
ON
®
BLINKS
D5
D6
D16
D30
H3
o
®
®
o
Compressor overload
protection sensor malfunction
All system functions are termi
nated except indoor fan.
Check for proper wiring and loose
connections at outdoor control in
put plug. Also, check for continuity
across overload protection sensor
terminals mounted at top of com
pressor.
H4
n
o
n
n
System operating abnormally
All system functions are termi
nated except indoor fan.
See unit information manual.
H5
o
®
o
n
Intelligent Power Module
protection
Intelligent Power Module
protection error can result from
any of the following:
S
Loss of cooling to the heat sink
S
Low voltage
S
High ambient temperature
S
Loose screws fastening the
outdoor control to the heat sink
Check all and correct, if necessary.
Lc
o
®
o
®
Unit start-up failure
All system functions are termi
nated.
See unit start-up troubleshooting
charts.
L3
n
o
o
o
Fan module protection
Outdoor unit operations are termi
nated. Indoor fan will run.
Check wire connections to outdoor
fan motor or fan motor module on
main board is damaged. Replace
main board.
PH
o
n
o
®
High voltage protection
All system functions are termi
nated.
S
Check input voltage on outdoor
unit terminal strip (N and L
terminals).
S
If voltage is higher than 265VAC,
disconnect power to unit. Correct
input voltage problem before
reapplying power to system.
S
If voltage is within normal range,
test capacitor output. If capacitor
range is between 200-208VAC,
replace outdoor control.
PL
o
n
n
o
Low voltage protection
All system functions are termi
nated.
S
Check input voltage on outdoor
unit terminal strip (N and L termi
nals).
S
If voltage is lower than 150VAC,
restart system and check power
again.
S
Check reactor (choke) line con
nection on outdoor control termi
nal marked INDC1.
PU
o
n
o
n
Capacitor charge failure
See unit information manual for
further information.
P5
o
®
o
o
Compressor overcurrent
protection
P7
o
o
n
®
Outdoor control failure
Replace outdoor control.
P8
n
o
®
n
Intelligent Power Module
temperature is too high
All system functions are termi
nated except indoor fan.
Intelligent Power Module high
temperature error can result from
any of the following:
S
Loss of cooling to the heat sink
S
Low voltage
S
High ambient temperature
S
Loose screws fastening the
outdoor control to the heat sink
Check all and correct, if necessary.
U1
o
®
n
o
Compressor current test circuit
malfunction
All system functions are termi
nated except indoor fan.
Replace outdoor control.
U3
o
n
n
n
Unstable DC voltage protection
Input voltage is not stable.
