22
TK 56433-5-MM-EN
Engine Compartment
Components
The following maintenance items can be checked
visually.
W
WA
AR
RN
NIIN
NG
G
R
Riisskk o
off IIn
njju
urry
y!!
T
Th
he
e u
un
niitt cca
an
n sstta
arrtt a
att a
an
ny
y ttiim
me
e w
wiitth
ho
ou
utt w
wa
arrn
niin
ng
g..
P
Prre
essss tth
he
e O
OF
FF
F kke
ey
y o
on
n tth
he
e H
HM
MII cco
on
nttrro
oll p
pa
an
ne
ell a
an
nd
d
p
plla
acce
e tth
he
e m
miiccrro
op
prro
occe
esssso
orr O
On
n//O
Offff ssw
wiittcch
h iin
n tth
he
e O
Offff
p
po
ossiittiio
on
n b
be
effo
orre
e iin
nssp
pe
eccttiin
ng
g o
orr sse
errv
viicciin
ng
g a
an
ny
y p
pa
arrtt o
off
tth
he
e u
un
niitt..
C
Co
om
mp
prre
esssso
orr O
Oiill S
Siig
gh
htt G
Glla
assss:: Use this sight glass to
check the compressor oil level. See the Refrigeration
Maintenance section for the correct procedure.
C
CA
AU
UT
TIIO
ON
N
S
Se
errv
viicce
e P
Prro
occe
ed
du
urre
ess!!
T
Tu
urrn
n tth
he
e u
un
niitt o
offff b
be
effo
orre
e a
atttte
em
mp
pttiin
ng
g tto
o cch
he
ecckk tth
he
e
e
en
ng
giin
ne
e o
oiill..
E
En
ng
giin
ne
e O
Oiill D
Diip
pssttiicckk:: Use the engine oil dipstick to
check the engine oil level.
R
Re
ecce
eiiv
ve
err T
Ta
an
nkk S
Siig
gh
htt G
Glla
assss:: Use this sight glass to
check the level of refrigerant in the receiver tank. See
the Refrigeration Maintenance section for the correct
procedure.
Figure 4. Engine Compartment Components
1.
Compressor Sight Glass
3.
Engine Oil Filter
2.
Engine Oil Dipstick
Unit Protection Devices
C
Co
oo
olla
an
ntt L
Le
ev
ve
ell S
Sw
wiittcch
h:: The coolant level switch closes
if the coolant level drops below an acceptable level. If it
stays closed for a specified time, the microprocessor
records Alarm Code 37.
E
En
ng
giin
ne
e C
Co
oo
olla
an
ntt T
Te
em
mp
pe
erra
attu
urre
e S
Se
en
nsso
orr:: The
microprocessor uses the engine coolant temperature
sensor to monitor the engine coolant temperature. If
the engine coolant temperature rises above an
acceptable level, the microprocessor records Alarm
Code 41 and possibly 18. The microprocessor might
also shut the unit down.
F
Fu
usse
e L
Liin
nkk ((C
Cu
urrrre
en
ntt L
Liim
miitte
err)):: The fuse link is located in
the positive battery cable. The fuse link protects the
electric system from a short. If the fuse link burns out,
replace it by replacing the positive battery cable.
F
Fu
usse
ess:: Various fuses are located on the base controller
to protect circuits and components. See “Fuses” in the
Electrical Maintenance Chapter for more information.
S
Sm
ma
arrtt F
FE
ET
Tss:: Smart FETs in the base controller protect
circuits and components. See “Smart FETs” in the
Electrical Maintenance Chapter for more information.
H
Hiig
gh
h P
Prre
essssu
urre
e C
Cu
utto
ou
utt S
Sw
wiittcch
h:: The high pressure
cutout switch is located on the compressor discharge
manifold. If the compressor discharge pressure
becomes excessive, the switch opens the circuit to the
run relay to stop the unit. The microprocessor will
record Alarm Code 10.
H
Hiig
gh
h P
Prre
essssu
urre
e R
Re
elliie
eff V
Va
allv
ve
e:: This valve is designed to
relieve excessive pressure in the refrigeration system.
It is located on the receiver tank. The valve is a spring-
loaded piston that lifts off its seat when refrigerant
pressure exceeds 500 psig (3447 kPa). The valve will
reseat when the pressure drops to 400 psig (2758 kPa).
The valve could possibly leak refrigerant after it has
relieved excess pressure. Tapping the valve lightly may
help the valve reseat and seal properly. The valve is
non-repairable and requires no adjustment. If the valve
fails to reseat properly, recover the refrigerant charge
and replace the valve.
L
Lo
ow
w O
Oiill L
Le
ev
ve
ell S
Sw
wiittcch
h:: The low oil level switch closes
if the oil drops below an acceptable level. If it stays
closed for a specified time, the microprocessor shuts
the unit down and records Alarm Code 66.
L
Lo
ow
w O
Oiill P
Prre
essssu
urre
e S
Sw
wiittcch
h:: The low oil pressure switch
closes if the oil pressure drops below an acceptable
level. If it stays closed for a specified time, the
microprocessor shuts the unit down and records Alarm
Code 19.
P
Prre
eh
he
ea
att B
Bu
uzzzze
err:: The preheat buzzer sounds when the
controller energizes the preheat relay. This warns
anyone near the unit that the controller is about to start
the engine.
Serial Number Locations
U
Un
niitt:: Nameplate on the frame inside the front doors.
E
En
ng
giin
ne
e:: Engine identification plate is located on the
engine valve cover.
C
Co
om
mp
prre
esssso
orr:: Stamped between the cylinders on the
front end above the oil pump.
