Thermo King VM-405 PBBD2 User manual

VM-405 PBBD2
TK 52317-E-1-MM (Rev. 1, 2/09)
Copyright©2004 Thermo King Corp., Minneapolis, MN, U.S.A.
Printed in U.S.A.

The contents of this manual covers information related to the VM-405 PBBD2 unit.
For further information, refer to…
VM-405 PBBD2 Operating Manual TK 52318-E-1-OP
The information in this manual is provided to assist owners, operators and service people in the proper upkeep
and maintenance of Thermo King units.
This manual is published for informational purposes only and the information so provided should not be considered
as all-inclusive or covering all contingencies. If further information is required, Thermo King Corporation should be
consulted.
Sale of product shown in this manual is subject to Thermo King’s terms and conditions including, but not limited to,
the Thermo King Limited Express Warranty. Such terms and conditions are available upon request.
Thermo King’s warranty will not apply to any equipment which has been “so repaired or altered outside the manu-
facturer’s plants as, in the manufacturer’s judgment, to effect its stability.”
No warranties, express or implied, including warranties of fitness for a particular purpose or merchantabil-
ity, or warranties arising from course of dealing or usage of trade, are made regarding the information, rec-
ommendations, and descriptions contained herein. Manufacturer is not responsible and will not be held
liable in contract or in tort (including negligence) for any special, indirect or consequential damages,
including injury or damage caused to vehicles, contents or persons, by reason of the installation of any
Thermo King product or its mechanical failure.

Recover Refrigerant
At Thermo King, we recognize the need to preserve the environ-
ment and limit the potential harm to the ozone layer that can
result from allowing refrigerant to escape into the atmosphere.
We strictly adhere to a policy that promotes the recovery and
limits the loss of refrigerant into the atmosphere.
In addition, service personnel must be aware of Federal regula-
tions concerning the use of refrigerants and the certification of
technicians. For additional information on regulations and tech-
nician certification programs, contact your local THERMO KING
dealer.
WARNING: Use ONLY Polyol Ester based refrigeration compressor oil (TK P/N 203-513).
DO NOT use Polyol Ester based oil in standard Thermo King units.
DO NOT mix Polyol Ester and standard synthetic compressor oils.
Keep Polyol Ester compressor oil in tightly sealed containers. If Polyol Ester oil becomes
contaminated with moisture or standard oils, dispose of properly—DO NOT USE!
WARNING: When servicing Thermo King R-404A units, use only those service tools
certified for and dedicated to R-404A refrigerant and Polyol Ester compressor oils.
Residual non-HFC refrigerants or oils will contaminate R-404A systems.
R-404A

Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Maintenance Inspection Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Defrost Timer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Protection Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Starting the Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Electronic Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Electrical Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Electric Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
P.C. Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Fuses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Troubleshooting Cab Control Box M13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Defrost Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Defrost Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Defrost Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Testing the Defrost System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Refrigeration Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Charging an Evacuated Unit by Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
High Pressure Cutout Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Refrigeration Service Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Compressor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Filter Drier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Evaporator Assy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
High Pressure Cutout (HPCS). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Low Pressure Cutout Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Hot Gas Solenoid Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Low Side Pumpdown Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Compressor Pumpdown Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Installing and Purging a Gauge Manifold Equipped with Low Loss Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Removing the Gauge Manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
SettingThe CPR Valve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Table of Contents (continued)
Structural Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Unit Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Evaporator Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Condenser Coil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Unit MountingBolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .29
Mechanical Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Electrical Mechanical Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Refrigeration Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Wiring Diagrams and Schematic Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

i
Safety Precautions
GENERAL PRACTICES
1. ALWAYS WEAR GOGGLES OR SAFETY
GLASSES. Refrigerant liquid, refrigeration oil, and
battery acid can permanently damage the eyes (see First
Aid under Refrigeration Oil).
2. Never operate the unit with the compressor discharge
valve closed.
3. Keep your hands, clothing and tools clear of the fans
and belts when the unit is running. This should also be
considered when opening and closing the compressor
service valves.
4. Make sure gauge manifold hoses are in good condition.
Never let them come in contact with a belt, fan motor
pulley, or any hot surface.
5. Never apply heat to a sealed refrigeration system or
container.
6. Fluorocarbon refrigerants, in the presence of an open
flame or electrical short, produce toxic gases that are
severe respiratory irritants capable of causing death.
7. Make sure all mounting bolts are tight and are of cor-
rect length for their particular application.
8. Use extreme caution when drilling holes in the unit.
The holes may weaken structural components, and
holes drilled into electrical wiring can cause fire or
explosion.
9. Use caution when working around exposed coil fins.
The fins can cause painful lacerations.
10. Use caution when working with a refrigerant or refrig-
eration system in any closed or confined area with a
limited air supply (for example, a truck box or garage).
Refrigerant tends to displace air and can cause oxygen
depletion resulting in suffocation and possible death.
11. EPA Section 608 Certification is needed to work on
refrigeration systems.
REFRIGERANT
Although fluorocarbon refrigerants are classified as safe
refrigerants, certain precautions must be observed when
handling them or servicing a unit in which they are used.
When exposed to the atmosphere from the liquid state, fluo-
rocarbon refrigerants evaporator rapidly, freezing anything
they contact.
First Aid
In the event of frost bite, the objectives of First Aid are to
protect the frozen area from further injury, to warm the
affected area rapidly and to maintain respiration.
• EYES: For contact with liquid, immediately flush eyes
with large amounts of water and get prompt medical
attention.
• SKIN: Flush area with large amounts of lukewarm
water. Do not apply heat. Remove contaminated cloth-
ing and shoes. Wrap burns with dry, sterile, bulky
dressing to protect from infection/injury. Get medical
attention. Wash contaminated clothing before reuse.
• INHALATION: Move victim to fresh air and use CPR
if necessary. Stay with victim until arrival of emer-
gency medical personnel.
REFRIGERATION OIL
Avoid refrigeration oil contact with the eyes. Avoid pro-
longed or repeated contact of refrigeration oil with skin or
clothing. Wash thoroughly after handling refrigeration oil to
prevent irritation.
First Aid
In case of eye contact, immediately flush with plenty of
water for at least 15 minutes. Wash skin with soap and
water. CALL A PHYSICIAN.

Safety Precautions (Rev. 1, 2/09)
ii
ELECTRICAL HAZARDS
High Voltage
When servicing or repairing a refrigeration unit, the possi-
bility of serious or even fatal injury from electrical shock
exists. Extreme care must be used when working with an
operating refrigeration unit. Lethal voltage potentials can
exist on connections in the high voltage tray of the control
box.
Precautions
1. When working on high voltage circuits on the refrigera-
tion unit, do not make any rapid moves. If a tool drops,
do not grab for it. People do not contact high voltage
wires on purpose. It occurs from an unplanned move-
ment.
2. Use tools with insulated handles that are in good condi-
tion. Never hold metal tools in your hand if exposed,
energized conductors are within reach.
3. Treat all wires and connections as high voltage until a
meter and wiring diagram show otherwise.
4. Never work alone on high voltage circuits on the refrig-
eration unit, another person should always be standing
by in the event of an accident to shut off the refrigera-
tion unit and to aid a victim.
5. Have electrically insulated gloves, cable cutters and
safety glasses available in the immediate vicinity in the
event of an accident.
First Aid
IMMEDIATE action must be initiated after a person has
received an electrical shock. Obtain immediate medical
assistance if available.
The source of shock must be immediately removed by
either shutting down the power or removing the victim from
the source. If it is not possible to shut off the power, the wire
should be cut with either an insulated instrument (e.g., a
wooden handled axe or cable cutters with heavy insulated
handles) or by a rescuer wearing electrically insulated
gloves and safety glasses. Whichever method is used do not
look at the wire while it is being cut. The ensuing flash can
cause burns and blindness.
If the victim has to be removed from a live circuit, pull the
victim off with a non-conductive material. Use the victim’s
coat, a rope, wood, or loop your belt around the victim’s leg
or arm and pull the victim off. DO NOT TOUCH the victim.
You can receive a shock from current flowing through the
victim’s body. After separating the victim from power
source, check immediately for the presence of a pulse and
respiration. If a pulse is not present, start CPR (Cardio Pul-
monary Resuscitation) and call for emergency medical
assistance. If a pulse is present, respiration may be restored
by using mouth-to-mouth resuscitation, but call for emer-
gency medical assistance.
Low Voltage
Control circuits used in the refrigeration unit are low volt-
age (24 volts dc). This voltage potential is not considered
dangerous, but the large amount of current available (over
30 amperes) can cause severe burns if shorted or ground.
Do not wear jewelry, watch or rings. These items can short
out electrical circuits and cause severe burns to the wearer.

1
Specifications
Design Features
• M13 Controller
• Digital Thermometer
• Electronic Thermostat, adjustable
from -26 F to 86 F
•DefrostTimer
• Hot Gas Defrost
• Defrost Termination Switch
• Manual Defrost Switch
• Receiver Tank with Outlet Service Valve
• 2HP Semihermetic Compressor 50/60 Hz
• Compressor Thermal Protection
• Hourmeter
• 100W Lamp Plug
• Draining Heater Wire Resistances
• Electric Resistant Heaters (750 W)
Standby AC Motor
Refrigeration Specifications
CAUTION: When the oil is removed from the compressor, oil level should be noted so that the same
level can be maintained in the replacement compressor.
CAUTION: Polyol Ester compressor oil should be used in standard Thermo King units, and PAG-type
or mineral oils should not be added to systems using R404A.
Voltage Phase Frequency Horsepower Full Load
Current
230/400 3 50/60 Hz 2 14.1/8.1A
Total System Oil Charge 1250 cc (42.2 oz.)
Compressor Oil Type Polyol Ester P/N 203513
Refrigerant Charge and Type 2.2 kg (4.8 lb) R-404A
Defrost Method Hot Gas
Defrost Termination Switch: Opens
Closes
8.9 ± 3C (48 ± 5.4 F)
2.2 ± 3C (36 ± 5.4 F)
High Pressure Cutout Switch Opens
Closes
450 ± 10 psi
375 ± 10 psi
Low Pressure Cutout Switch Opens
Closes
5 to 11 inch. Vacuum
27.6 to 48.3 kPa (4 to 7 psi)
Defrost Timer: Initiation Interval From 1 minute to 10 hours
Termination Interval When Defrost Termination Switch opens

Specifications (Rev. 1, 2/09)
2
Condenser & Evaporator Fan Motors
Fuses
Hot Gas Solenoid Coils
Heaters
Voltage Number Power Rating
in W. Full Load RPM Full Load Current
Evaporator 26 V 2 100 2800 5.2 A
Condensor 26 V 1 180 2800 8.9 A
Voltage
Evaporator
fan
Fuse 1
Evaporator
fan
Fuse 2
Condenser
fan
Fuse 3
M-13
Fuse 4
M-13
Fuse 4/1
Transformer
Fuse 5
24 V 10 A 10 A 15 A 3 A 3 A 5 A
Voltage
External
lamp
Fuse 6
External
lamp
Fuse 7
24 V 1 A 1 A
Voltage Current Resistance
24 V 1.3 A 20 Ohms
Voltage AC Number Power in W. Full Load Current
220 V 2 750 3.5 A

3
Maintenance Inspection Schedule
First Week Inspection and Maintenance
AFTER FIRST WEEK OF OPERATION:
• Tighten the unit and mount bracket mounting bolts
Bi-monthly Annually Inspect/Service These Items
ELECTRICAL
••
Check defrost initiation and termination.
••
Check thermostat cycle sequence.
••
Check operation of protection shutdown circuits.
•Check thermostat and thermometer calibration in 32 F (0 C) ice-water bath.
•Inspect wire harness for damaged wires or connections.
REFRIGERATION
••
Check refrigerant level.
•Replace dehydrator.
STRUCTURAL
••
Visually inspect unit and refrigerant hoses for fluid leaks.
••
Visually inspect unit for damaged, loose or broken parts.
••
Clean defrost drains.
••
Clean entire unit including evaporator coil and condenser coil.
••
Check all unit mounting bolts, brackets, lines, etc.

4

5
Unit Description
The Thermo King VM 405 PBBD2 refrigeration system is a
one-piece nose mounted unit. It uses a semihermetic com-
pressor in the condenser section for cooling operation.
The unit is designed for low and medium temperature
small-sized compartments. It can cool and defrost on elec-
tric compressor operation to refrigerate one compartment
with R404A. Heating is accomplished by connecting the
heating resistances.
The control circuits operate on 24 Vdc rectified from an AC
transformer. Each refrigeration system is protected by high
and low pressure cutout switches.
Unit operation is performed from a remote control box. It
includes an On/Off switch, manual defrost switch, ther-
mometer, thermostat, thermostat adjustment, and indicator
lights.
Compressor operation is controlled by the thermostat, ener-
gizing the compressor contact during cooling operation.
Defrost: A hot gas solenoid valve provides local heat to the
evaporator by means of hot gas from the discharge line. An
electronic defrost timer can initiate defrost automatically.
Defrost is normally terminated by the defrost termination
switch mounted on the evaporator coil. The defrost cycle
can be terminated by pressing the On/Off switch.
DEFROST TIMER
The defrost timer automatically initiates the defrost cycle at
preset intervals.
The Defrost Timer is powered directly by the standby power
supply. This means that the Defrost Timer is counting when-
ever the unit is connected to the main supply (while Klixon
is closed), even when the unit is switched off.
PROTECTION FEATURES
• High Pressure Cutout Switch
The High Pressure Cutout Switch is a pressure-sensi-
tive switch located in the discharge line. If the dis-
charge pressure rises above 450 psi (3100 kPa), the
switch opens the circuit to the PR Relay to stop the
unit. When the discharge pressure falls below 375 psi
(2600 kPa), the switch closes.
• Low Pressure Cutout Switch
The Low Pressure Cutout Switch is a pressure-sensitive
switch located in the suction line. If the pressure falls
below 5 to 11 inch vacuum, the switch opens the circuit
to the PR Relay to stop unit operation. The switch
closes at 4 to 7 psi.
• Overload Relay Protection for Electric Motor
• Overload Relay Protection for heater resistance
•Fuses
• Power Cord LED
• Overload Relay LED
• Thermistor: Disconnects AC motor if its temperature
reaches a threshold value.
OPERATION
General
These units cycle among Heat, Cool and Null to maintain
the box temperature at the thermostat setpoint. The operat-
ing modes are: Cool, Null, Heat and Defrost.
The thermostat controls the operation of the unit by energiz-
ing and de-energizing the Power Relay PR.
When the Power Relay is energized, the condenser fans are
powered up (as well as the compressor motor).

Unit Description (Rev. 1, 2/09)
6
When the unit is connected to the main supply, the external
lamp is powered up by 110 V.
Operating Modes
Cool
The thermostat energizes the Power Relay at box tempera-
tures higher than setpoint. The thermostat keeps the Power
Relay energized while the box temperature is higher than
4 F (2.2 C) above setpoint. The Power Relay energizes the
evaporator and condenser fan relays, the drain heaters and
the compressor contactor. The fans and the compressor run
and the unit cools.
Null
The thermostat shifts from Cool to Null at box temperatures
lower than setpoint. The thermostat shifts the unit from
Cool to Heat at 4 F (2.2 C) below the setpoint. The thermo-
stat shifts the unit from Heat to Null at setpoint.
Heat
The thermostat shifts the unit to Heat at temperatures more
than 4 F (2.2 C) below the thermostat setpoint. The thermo-
stat keeps the unit running in Heat until the temperature
reaches the thermostat setpoint.
When the unit is in Heat mode, the thermostat drives the
heater contactor, the evaporator fans and the electric resis-
tant heaters, and the unit heats.
Defrost
The Defrost cycle can be initiated any time the evaporator
coil temperature is below 36 F. Defrost is initiated automati-
cally by the defrost timer, or manually by pressing the man-
ual defrost switch.
When the Power Relay is energized, the drain heaters are
activated and the defrost relay energizes the Solenoid Valve
PS to route hot refrigerant gas to the evaporator. The defrost
relay also interrupts power to the fan relays to stop the evap-
orator and condenser fans during defrost.
The Defrost cycle will continue until the evaporator coil
temperature rises to 48 F, causing the defrost termination
switch to open. Defrost cycle can also be terminated by
pressing the On/Off switch twice.
Operating Modes
1. Temperature Drop
2. Setpoint
3. 4 F
4. Temperature Rise
5. 4 F
6. Cool
7. Null
8. Heat
1
2
3
4
5
6
7
8ANA144

7
Operating Instructions
Leaks
Inspect for refrigerant leaks and worn refrigerant lines.
Electrical
Electrical connections should be securely fastened. Wires
and terminals should be free of corrosion, cracks or mois-
ture.
Defrost Drain
Check the defrost drain hose and fittings to be sure that they
are open so condensation can run out during defrosting.
Check the bottom end of the drain hose to be sure that it is
not plugged or crushed.
Structural
Visually check for physical damage.
Sightglass
Check for proper refrigerant charge level.
STARTING THE UNIT
Electric Operation
1. Connect the external power supply to the power recep-
tacle. Make sure that the power supply voltage is cor-
rect for the unit. The Power Cord LED must be ON.
2. Press the On/Off Switch in the Control Box. The On/
Off LED must be ON.
3. Adjust the thermostat setting.
After Start Inspection
Thermostat
Dial the thermostat setting above and below the box
temperature to check thermostat operation.
Pre-Cooling
With the thermostat set at the desired temperature, allow the
unit to run for one-half to one hour before loading the con-
tainer. Pre-cooling will remove residual body heat and
moisture from the box interior and provide a good test of the
refrigeration system.
Defrost
When the unit has finished pre-cooling, the container
interior (evaporator temperature dropped below 2.2 C/36 F),
initiate a defrost cycle with the manual defrost switch. The
defrost cycle should end automatically.
Loading Procedure
1. Be sure the unit is OFF before opening the door to min-
imize frost accumulation on the evaporator coil and
heat gain inside the box.
2. Spot check and record load temperature while loading.
Especially note any off-temperature product.
3. Load product so that there is adequate space for air cir-
culation completely around the load. DO NOT block
the evaporator inlet or outlet.
4. Products should be pre-cooled before loading. Thermo
King units are designed to maintain loads at a consis-
tent temperature, NOT to cool down hot loads.

Operating Instructions (Rev. 1, 2/09)
8
Post Load Procedure
To remove excess moisture before storage:
1. Be sure all doors are closed and locked.
2. Adjust the thermostat to the desired temperature set-
point.
3. Start the unit.
4. Half an hour after loading, defrost the unit by momen-
tarily pressing the Manual Defrost switch. If the coil
temperature drops below 36 F, the unit will defrost. The
defrost cycle should stop automatically.
ELECTRONIC CONTROLS
Units are equipped with an M13 controller. The controller
regulates unit functions and displays operating information
quickly and accurately.
WARNING: Do not operate the unit until you are
completely familiar with the display screen and
function of each control key.
The M13 controller automatically displays the return air
temperature; provides temperature control from -26 to 86 F
(-32 to 30 C) in 2 F (1 C) increments; and automatically
defrosts every three hours.
NOTE: The defrost interval is set at the factory. The inter-
val may be reset, if needed, by a certified Thermo King
technician.

Operating Instructions (Rev. 1, 2/09)
9
Figure 1: M13 Controller
Table 1: M13 Components
1. ON Indicator Light 5. Defrost Indicator Light 9. AC Overload Led 13 Thermostat Dial
2. ON-OFF Key 6. Manual Defrost Key 10. Setpoint Led 14. Digital Display
3. Power Cord Indicator Light 7. Celsius Led Indicator 11. Setpoint Key Indicator
4. Unit Operation Indicator Light 8. Fahrenheit Led Indicator 12. Setpoint Key
7
13
8
9
11
12
AKB72
10
1456
2
1
3
4

Operating Instructions (Rev. 1, 2/09)
10
M13 Unit Controls
On-Off Key Press this key to turn the unit ON and OFF.
When the unit has been stopped by the HEAT or COOL
Overload Relay, press this key to restart the unit.
ON Indicator When this light is on, it indicates that the unit
is turned ON. When this light is off, it indicates that the unit
is turned OFF.
Power Cord Indicator When this light is on, it indicates
that the unit is connected to an AC voltage power supply.
Unit Operation Indicator Light When this light is on, it
indicates that the unit is operating. This light indicates both
cooling and heating modes. If the light is green, the unit is
cooling. If the light is red, the unit is heating. When the unit
is stopped by the thermostat, HPCO, or LPCO, the Unit
Operation Indicator Light must be OFF and the ON Indica-
tor must remain ON.
Manual Defrost Key Press this key to start a defrost cycle.
The unit will not defrost unless the defrost termination
switch is closed and the evaporator coil temperature is
below 36 F (2 C).
Defrost Indicator When this light is on, it indicates that the
unit is in defrost.
Digital Display This display is active only when the unit is
turned on. The thermometer reading (return air sensor tem-
perature) normally appears on the display.
Celsius Indicator When this light is on, it indicates that the
temperature is being displayed in degrees Celsius.
Fahrenheit Indicator When this light is on, it indicates that
the temperature is being displayed in degrees Fahrenheit.
AC Overload Indicator When this light is on, it indicates
that the overload relay has opened and the unit has been
stopped. This indicator must be reset by pressing the On-Off
Key after allowing time for the overload relay to cool.
Setpoint Key Press this key to make the thermostat setpoint
appear on the digital display. The thermostat setpoint will
remain on the display for 10 to 15 seconds after the key is
released. This gives the operator time to adjust the thermo-
stat setpoint.
Thermostat Dial Turn this dial to adjust the thermostat set-
point.
NOTE: The Thermostat Dial will change the thermostat
setpoint without pressing the Setpoint Key.
M13 Display Information
With the unit or the controller OFF, the display screen will
be dark—nothing will appear on the display screen. When
the unit ON/OFF key is pressed ON, the Unit Operation
Indicator Light will be lit.
The unit will display the return air temperature or the set-
point temperature on the display screen, depending on the
current operating mode.
When the unit is switched OFF, the screen is blank and the
Unit Operation Indicator Light goes OFF.
M13 Display Operating Data
During normal operation, the return air temperature remains
on the display screen. To display the setpoint, press the set-
point key.
NOTE: The setpoint will remain on the display screen for
10 seconds after the setpoint key has been pressed.

Operating Instructions (Rev. 1, 2/09)
11
M13 Initiate Manual Defrost
You may initiate a manual defrost anytime the evaporator
coil temperature is below 36 F (2 C).
1. Press the manual defrost key. The defrost will light,
indicating that the unit is defrosting. The unit will auto-
matically return to the proper operating mode when the
defrost cycle is finished. The unit will return to cooling
mode automatically when the coil temperature reaches
48 F (8.9 C).
2. To end the defrost cycle before automatic termination,
press the ON/OFF key to OFF.
M13 Enter The Setpoint
The setpoint can be easily changed once you are familiar
with the controls.
1. Press the setpoint key and the setpoint temperature is
displayed on the screen.
2. Observe the controller display and turn the thermostat
dial to the desired setpoint temperature.
3. Release the setpoint key. The return air temperature
should appear on the display screen after 10 seconds.
CAUTION: Do not accidentally move the thermo-
stat dial. The setpoint temperature can be changed
by moving the dial without pressing the setpoint
key.

12