13
TROUBLESHOOTING INFORMATION: CONDENSING UNIT
For detailed service information refer to the Remote Condensing Unit Service manual.
Com plaint
Sys te m
Ope r ating
Pr e s s ur e s
POSSIBLE CAUSE
DOTS IN ANALYSIS
GUIDE INDICATE
"POSSIBLE CAUSE"
SYM
PT
O
M
S
y
s
te
m
w
ill
no
t s
tar
t
C
o
m
p
re
s
s
o
r w
ill
n
o
t s
ta
rt
-
f
a
n
r
u
n
s
C
o
m
p
. a
n
d
C
o
n
d
. F
a
n
w
ill n
o
t
s
ta
rt
Ev
a
p
o
ra
to
r f
a
n
w
ill
n
o
t s
ta
rt
C
o
n
d
e
n
s
e
r f
a
n
w
ill
n
o
t s
ta
rt
C
o
m
p
re
s
s
o
r r
u
n
s
-
go
es
of
f on
o
v
e
rl
o
a
d
Com
p
re
s
s
or
c
y
c
le
s
on
ov
er
lo
ad
Sy
s
te
m
r
u
n
s
c
o
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tin
u
o
u
s
ly
-
lit
tl
e
c
o
o
lin
g
/h
tg
T
o
o c
o
o
l an
d
th
e
n
t
o
o
w
a
rm
N
o
t c
ool
en
ou
gh
on
w
a
rm
d
a
y
s
Cer
tai
n
ar
ea
s
t
o
o c
o
ol
, ot
h
e
rs
t
o
o w
a
rm
Com
p
re
s
s
or
i
s
no
is
y
S
y
s
te
m
r
u
n
s
-
bl
ow
s
c
o
ld
a
ir
in
h
eat
in
g
U
n
it w
ill n
o
t t
e
rm
in
a
te
d
e
fr
o
s
t
U
n
it w
ill n
o
t d
e
fr
o
s
t
Low
s
u
c
tio
n
p
res
s
u
re
L
o
w
he
ad
pr
es
s
u
re
Hi
gh
s
u
c
tio
n
pr
es
s
u
re
Hi
gh
he
ad
pr
es
s
u
re
Te st Me thod
Re m e dy
Pow er Failure
•
Test V oltage
Blow n Fuse
•
• •
Inspect Fuse Size & Type
Unbalanced Pow er, 3PH
•
• •
Test V oltage
Loose Connection
•
•
•
Inspect Connection - Tighten
Shorted or Broken Wires
• • • • • •
Test Circuits With Ohmmeter
Open Fan Overload
• •
Test Continuity of Overload
Faulty Thermostat
•
• •
•
Test Continuity of Thermostat & Wiring
Faulty Transf ormer
•
•
Check Control Circuit w ith V oltmeter
Shorted or Open Capacitor
•
• • • •
Test Capacitor
Internal Compressor Overload Open
•
♦
Test Continuity of Overload
Shorted or Grounded Compressor
•
•
Test Motor Windings
Compressor Stuck
•
• •
♦
Use Test Cord
Faulty Compressor Contactor
•
• •
Test Continuity of Coil & Contacts
Faulty Fan Relay
•
Test Continuity of Coil A nd Contacts
Open Control Circuit
•
Test Control Circuit w ith V oltmeter
Low V oltage
•
• •
Test V oltage
Faulty Evap. Fan Motor
•
•
♦
Repair or Replace
Shorted or Grounded Fan Motor
•
•
Test Motor Windings
Improper Cooling A nticipator
•
•
Check Resistance of A nticipator
Shortage of Ref rigerant
• •
♦
• •
Test For Leaks, A dd Ref rigerant
Restricted Liquid Line
• •
• •
•
Remove Restriction, Replace Restricted Part
Open Element or Limit on Elec. Heater
♦
♦
Test Heater Element and Controls
Dirty A ir Filter
•
• •
•
♦
Inspect Filter-Clean or Replace
Dirty Indoor Coil
•
• •
•
♦
Inspect Coil - Clean
Not enough air across Indoor Coil
•
• •
•
♦
Check Blow er Speed, Duct Static Press, Filter
Too much air across Indoor Coil
♦
•
Reduce Blow er Speed
Overcharge of Ref rigerant
• •
•
♦
• •
Recover Part of Charge
Dirty Outdoor Coil
• •
•
♦
•
Inspect Coil - Clean
Noncondensibles
•
•
♦
•
Recover Charge, Evacuate, Recharge
Recirculation of Condensing A ir
•
•
•
Remove Obstruction to A ir Flow
Inf iltration of Outdoor A ir
•
• •
Check Window s, Doors, V ent Fans, Etc.
Improperly Located Thermostat
•
•
Relocate Thermostat
A ir Flow Unbalanced
•
•
Readjust A ir V olume Dampers
System Undersized
•
•
Ref igure Cooling Load
Broken Internal Parts
•
♦
Replace Compressor
Broken V alves
•
•
• •
Test Compressor Ef f iciency
Inef f icient Compressor
•
♦
• •
Test Compressor Ef f iciency
Wrong Type Expansion V alve
• • •
•
• •
♦
Replace V alve
Expansion Device Restricted
• • •
•
• •
•
Remove Restriction or Replace Expansion Device
Oversized Expansion V alve
•
•
Replace V alve
Undersized Expansion V alve
• • •
•
•
Replace V alve
Expansion V alve Bulb Loose
•
•
Tighten Bulb Bracket
Inoperative Expansion V alve
•
•
•
Check V alve Operation
Loose Hold-dow n Bolts
•
Tighten Bolts
Faulty Reversing V alve
•
♦ ♦ ♦
♦ ♦ ♦
Replace V alve or Solenoid
Faulty Def rost Control
•
♦ ♦ ♦ ♦ ♦
♦
Test Control
Faulty Def rost Thermostat
♦ ♦ ♦ ♦ ♦ ♦ ♦
Test Def rost Thermostat
Flow rator Not Seating Properly
•
• •
Check Flow rator & Seat or Replace Flow rator
•
Cooling or He ating Cycle (He at Pum p)
♦
No Cooling
Uns atis factor y
Cooling/He ating
He ating Cycle Only (He at Pum p)
