87
MAINTENANCE
11. Capac
ity
too
great
Rep
l
ace
,
repair
or
re
-
set
Fault
Probable cause
Action required
1. Suct
i
on Temperature
too
high
Too
mu
ch suct
i
on gas superheat
(
above 20K)
E
xamine
and ad
ju
st
the thermostatic
expans
ion
valves
in
the
evaporators
1
L
iquid in
the
suct
i
on
lin
e
Ad
just thermostatic
expans
i
on
valves
1
2
.
Suct
i
on Temperature
too
l
ow
Sensor
i
s
l
oose
or
in
correct
ly
positioned
Check
if
the
sensor
i
s
in
contact
with the
suct
i
on
lin
e and
replace
if
necessary
3. Suct
i
on Pressure
too
l
ow
Too
much oil
in
evaporators
Dra
in
oil from
evaporators
1
F
ilt
er
in
the
liquid lin
e
clogged
E
xam
in
e and
clean filters
in liquid lin
e
Too
much
superheat of suct
ion
gas
Ad
just thermostatic
expans
ion
valves
1
In
sta
ll
at
i
on
in
suff
i
c
i
ently charged
Charge
the
in
sta
ll
at
i
on
with refrigerant
4. Compressorcuts
in
and out
too often
on
L
P safety sw
it
ch
5. Suct
i
on Pressure
too high
6. Gas coo
l
er Pressure
too high
See
point3
1
E
vaporator
i
ced
over
or frozen water
present
in
the distributor
C
l
ean
or defrost
evaporator
Restart after
defrost
Wait for
conf
irm
at
i
on
Compress
ion
prob
l
ems
Change compressor
1
ln
suff
i
c
i
entf
low
of
a
ir in
to the
gas
coo
l
er
C
l
ean
the
gas coo
l
er. Check
motor fans
In
sta
ll
at
i
on
overcharged
Dra
in liquid int
o
reservoir
1
A
ir
or non
-
condensab
l
e gas
in
the HP
c
ir
cu
it
Dra
in,
use
a
vacuum pump
and
recharge
1
7. Gas coo
l
er Pressure
too
l
ow Fan eut-
in in
correct
ly
set
Ad
just
1
8.
D
i
scharge Temperature
too
high
Too
mu
ch superheat on suct
i
on
Ad
just thermostatic
expans
ion
valves
Int
erna
i
by-pass
Check compressor
9. O
il
Temperature
too high
Superheat on suct
i
on
too
great
Check and ad
ju
st
thermostatic
expans
i
on
valves
1
O.
Oil temperature too
l
ow
Oil return
saturated
in li
qu
id
refrigerant
Ad
just
e
l
ectron
i
c expans
i
on
valve
Prob
l
em
with
contro
l
system or
other
automat
i
c
deviees
Rep
l
ace
,
repair
or
re
-
set
12.
lnsufficient
Capac
ity
Prob
l
em
with
contro
l
system or other
automat
i
c dev
i
ees
13.
Oil foams heavily
after
Thermostat
i
c expans
i
on
valve
(fluid in
suct
i
on
lin
e
)
Check thermostatic
expans
i
on
valve
stoppage
Sensor
l
oose or
in
correct
ly
pos
iti
oned Check bu
lb
pos
iti
on
Crankcase heater
out of
order
Rep
l
ace
heater
