Carrier GEN IV User manual

R
OPERATOR’S MANUAL
for
SPLIT SYSTEM
Bus Air Conditioning Units
T--326 Rev --
Transport Air Conditioning
TRANSPORT AIR CONDITIONING

OPERATOR’S
MANUAL
BUS AIR CONDITIONING
UNITS
GEN IV & GEN V

i
CONTENTS
Page
Introduction 1............................
Safety 3..................................
Unit/System Information 4.................
1.1 WHAT IS AIR CONDITIONING 4.............
1.2 SPLIT SYSTEM 4..........................
1.3 SYSTEM DESIGNATIONS 4................
1.4 SYSTEM COMPONENTS 4.................
1.5 MODEL AND SERIAL NUMBER TAGS 6......
1.6 SYSTEM REQUIREMENTS LABEL 8........
Unit Operation 9..........................
2.1 OPERATING INSTRUCTIONS 9.............
2.2 DRIVER’S CONTROL PANEL -- STANDARD 9.
2.3 DRIVER’S CONTROL PANEL -- FLORIDA 10...
2.4 PRE--TRIP INSPECTION 12..................
System Maintenance 13....................
3.1 Maintenance Schedule 13....................
3.2 Warranty/Service 14.........................
Index Index 1...............................

1
INTRODUCTION
SPLIT SYSTEM OPERATOR’S MANUAL
This guide has been prepared for the operator of Carrier Transport
Air Conditioning systems. It contains basic instructions for the daily
operation of the air conditioning system as well as safety
information, and other information that will help you to maintain a
comfort level for your self and your passengers. Please take the
time to read the information contained in this booklet and refer to
it whenever you have a question about the operation of your Carrier
Transport Air Conditioning system.
More comprehensive information can be found in the Split System
Operation and Service Manual (T--299). This manual can be
obtained from your Carrier Transport A/C dealer.
Your air conditioning system has been engineered to provide long,
trouble-free performance when it is properly operated and
maintained. A comprehensive maintenance program will help to
insure that the unit continues to operate reliably. Such a
maintenance program will also help to control operating costs,
increase the unit’s working life, and improve performance.
Some Vehicles may require information from manuals supplied by
the vehicle manufacturer or other special equipment suppliers. We
urge you to review all these publications carefully. This will help you
enjoy safe and trouble--free operation of your vehicle.
When having your unit serviced, be sure to specify genuine Carrier
Transicold replacement parts for the highest quality and best
reliability.
Carrier Transport Air Conditioning Dealers know your vehicle air
conditioning system best and will ensure your complete
satisfaction. To find the Dealer nearest you, go to
www.transportaircon.carrier.com and click on “Dealer Locator”, or
refer to the Carrier Bus Stop Dealer Directory (62--10810) or
contact the Carrier Transport Air Conditioning Technical Service
Hot--Line 1 (800) 450--2211.
At Carrier Transport Air Conditioning, we are continually working to
improve the products that we build for our customers. As a result,
specifications may change without notice.

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SAFETY
Your Carrier Transport Air Conditioning system has been designed
with the safety of the operator in mind. During normal operation, all
moving parts are fully enclosed to help prevent injury. During all
pre-trip inspections, daily inspections, and problem
troubleshooting, you may be exposed to moving parts; please stay
clear of all moving parts when the unit is in operation.
WARNING
Beware of unannounced starting of the unit. The unit
may cycle the fans and operating compressor unex-
pectedly as control requirements dictate. Turn system
off and disconnect battery power.
REFRIGERANT
The refrigerant contained in the air conditioning system can cause
frostbite, severe burns, or blindness when in direct contact with the
skin or eyes. For this reason, and because of legislation regarding
the handling of refrigerants during system service, we recommend
that, whenever your unit requires service of the refrigeration
system, you contact your nearest Carrier Transport Air
Conditioning authorized dealer for service.

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UNIT/SYSTEM INFORMATION
1.1 WHAT IS AIR CONDITIONING
Air Conditioning is the cooling, heating, dehumidification, and
filtration of the air within the passenger compartment of a vehicle.
1.2 SPLIT SYSTEM
A Split System normally includes an Evaporator(s), a Condenser(s)
a Compressor(s) and interconnecting refrigerant hoses, fittings,
and electrical harnesses and controls. A listing of the system
components, along with specific data for each, is provided in
Paragraph 1.4.
1.3 SYSTEM DESIGNATIONS
Tie--In System -- Is a Carrier evaporator and condenser connected
to an existing OEM compressor and dash evaporator. The OEM
radiator type condenser is normally removed.
Max System -- A Carrier system installed along with an existing
OEM system. The systems operate independent of each other.
Stand--Alone (Standard) System -- All Carrier components
installed on a vehicle. These can be either single or dual
compressor systems.
1.4 SYSTEM COMPONENTS (Refer To Figure 1-1)
Return Air Thermostat/Sensor -- The system may be supplied
with a thermostat or thermistor. Both of these devices are
temperature sensitive components which when activated, signals
the Electro--Magnetic Clutch to engage/disengage. The return air
thermostat is normally located in the drivers control panel while the
return air thermistor is normally located in the return air flow of the
evaporator assembly.
Electro--Magnetic Clutch -- The Electro--Magnetic clutch controls
the operation of the compressor. When engaged, the compressor
circulates refrigerant and provides cooling.
Compressor -- The compressor is a belt driven, high--pressure
pump, which circulates the refrigerant through the evaporator and
condenser . The operation of the compressor is controlled by the
Electro--Magnetic clutch.
Condenser -- The condenser is normally located in the skirt or on
the roof of the vehicle. Its primary function is to reject heat, which
was transferred to the refrigerant by the evaporator from the
passenger compartment of the vehicle.

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Air In
Air Out
Air In
Air Out
10
1
2
3
4
5
6
7
89
1. Compressor
2. Electro--Magnetic Clutch
3. Discharge Line
4. Condenser
5. Filter Dryer/Sight Glass
Assembly
6. Liquid Line
7. Evaporator
8. Block Valve (TXV)
9. Freezestat--(Coil
freeze--up thermostat)
10. Suction Line
Figure 1-1 Component Locations
Filter/Dryer -- The filter/dryer removes moisture and particulate
matter from the refrigerant.
Expansion/Block Valve -- Meters the refrigerant flow into the
evaporator coil. The majority of the Gen 4 (Excel) and all Gen 5
systems use a nonadjustable block valve with an 8°F superheat
setting, which is preset at the factory. If you feel there is a problem
with the block valve, do not attempt to adjust the valve, if needed,
it should be replaced by an authorized Carrier Transport A/C
service center.
Evaporator -- The evaporator is located in the interior of the
vehicle. Its primary function is to transfer heat contained in the
passenger compartment air, into the refrigerant, which is circulated
by the compressor, through the evaporator coil. During this process
the air is also filtered and dehumidified.
Resistor -- Resistors are used to control the speeds of the
permanent magnet evaporator blower motors.

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Pressure Switch -- The systems use high and low pressure
switches wired in series to control the power circuit of the
compressor clutch relay. If either pressure switch opens,
interrupting the circuit to the clutch relay, the operation of the
compressor will stop. When conditions return to normal the switch
will automatically reset and the compressor will resume operating.
The switches are non--adjustable.
Freeze--Up Thermostat -- Freeze--up thermostats are used to
prevent ice formation on the evaporator coil, which is an indication
that liquid refrigerat is getting back to the compressor. Carrier
Transport Air Conditioning systems use a freeze thermostat
(freezestat) wired in series with the system pressure switches and
thermostat/thermistor to control the operation of the compressor
clutch.
Refrigerant -- A refrigerant is a material that is used to move heat
from the passenger compartment to the outside air. It is a
substance that gives up heat by condensing at high temperature
and pressures and absorbs heat by evaporating at low
temperatures and pressures. The heat transfer properties
exhibited when refrigerant changes state is the foundation of the
refrigerant cycle.
1.5 MODEL AND SERIAL NUMBER TAGS
In order to identify the air conditioning components you have, you
will need to know the model number and serial number. All Carrier
Transport Air Conditioning evaporators, condensers and
compressors have a model/serial number tag located on the
assembly. See Figure 1-2 for skirt mounted condenser data tag
location, Figure 1-3 for the CM--7/11 rooftop condensers data tag
location, Figure 1-4 for GEN 4 (Excel) evaporator data tag location
and Figure 1-5 for GEN 5 evaporator data tag location. Knowing
these locations and the information on the data tags will aid you in
identifying the correct service procedures.
Figure 1-2 Skirt Mounted Condensers

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Figure 1-3 Roof Mounted Condensers
EM--9 Location
Figure 1-4 Rear/Side Mounted Gen IV Evaporators
NOTE
The EM--9 evaporator data tag is located on the side of the
evaporator assembly, not between the blower assemblies.
Figure 1-5 Rear/Side Mounted Gen V Evaporators

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1.6 SYSTEM REQUIREMENTS LABEL
The system requirements label (See Figure 1-6) is conveniently
located within the vehicle’s engine compartment. This label, when
properly completed by the installer, will give the servicing technician
the refrigerant and oil charge(s), evaporator(s), condenser(s), and
compressor(s) serial numbers, the drive belt(s) number, mount kit
number, the date of installation and the installer.
Figure 1-6 System Requirement Label