SECTION 22: HEATING AND AIR CONDITIONING
DOB 2490-2789 | X3-45 Commuter PA1605 Maintenance Manual (Final Version – Rev.2 April 2016)
1
CONTENTS
1.
HEATING
AND
AIR
CONDITIONING
SYSTEM
OVERVIEW
..................................................................
5
2.
AIR
CIRCULATION
..........................................................................................................................
8
2.1
DRIVER’S
AREA
................................................................................................................................
8
2.2
PASSENGERS’
AREA
.........................................................................................................................
8
3.
HVAC
SYSTEM
OPERATION
............................................................................................................
9
3.1
HVAC
CONTROL
UNIT
.....................................................................................................................
9
3.2
PASSENGERS’
SECTION
OPERATION
.............................................................................................
10
4.
HVAC
UNIT
BASIC
MAINTENANCE
................................................................................................
11
4.1
COIL
CLEANING
.............................................................................................................................
11
4.2
DRIVER'S
SECTION
AIR
FILTERS
.....................................................................................................
12
4.3
PASSENGERS’
SECTION
AIR
FILTER................................................................................................
13
4.4
PARCEL
RACK
FAN
AIR
FILTER
.......................................................................................................
13
5.
HVAC
SYSTEM
PARTICULARITIES,
TESTING
AND
TROUBLESHOOTING
...........................................
13
5.1
ON
DEMAND
DISPLAY
OF
A/C
COMPRESSOR
HIGH
AND
LOW
SIDE
PRESSURE
...........................
13
5.2
ON
DEMAND
ACTIVATION
OF
HOT
WATER
CIRCULATING
PUMP
................................................
14
5.3
HVAC
SYSTEM
AND
TEST
MODE
FOR
ELECTRIC
MOTORS
............................................................
14
5.4
MODES
OF
OPERATION
................................................................................................................
15
5.5
HVAC
SYSTEM
MULTIPLEX
TROUBLESHOOTING
...........................................................................
16
6.
AIR
CONDITIONING
SYSTEM
........................................................................................................
18
6.1
A/C
CYCLE
.....................................................................................................................................
18
6.2
REFRIGERANT
................................................................................................................................
18
6.2.1
Procurement
.........................................................................................................................
18
6.2.2
Precautions
in
Handling
Refrigerant
.....................................................................................
18
6.2.3
Treatment
in
Case
of
Injury
...................................................................................................
19
6.2.4
Precautions
in
Handling
Refrigerant
Lines
............................................................................
19
6.3
PUMPING
DOWN
..........................................................................................................................
20
6.3.1
Procedure
..............................................................................................................................
20
6.4
LIQUID
REFRIGERANT
RECOVERY
.................................................................................................
21
6.5
EVACUATING
SYSTEM
...................................................................................................................
22
6.6
ADDING
VAPOR
STATE
REFRIGERANT
..........................................................................................
22
6.6.1
Verification
............................................................................................................................
22
6.6.2
Refrigerant
addition
..............................................................................................................
23
6.7
CHARGING
SYSTEM
.......................................................................................................................
24
6.8
REFRIGERANT
SYSTEM
CLEAN
‐
OUT
AFTER
COMPRESSOR
FAILURE
.............................................
24
6.8.1
Determining
Severity
of
Failure
............................................................................................
24
6.8.2
Clean
‐
out
after
Minor
Compressor
Failure
...........................................................................
25
6.8.3
Clean
‐
out
After
Major
Compressor
Failure
...........................................................................
25
7.
A/C
SYSTEM
COMPONENTS
.........................................................................................................
25
7.1
COMPRESSOR
...............................................................................................................................
25
7.1.1
Belt
Replacement
..................................................................................................................
25
7.1.2
Belt
Tension
Adjustment
–A/C
drive
belt
..............................................................................
25
7.1.3
Suction
and
Discharge
Hose
Connection
...............................................................................
26
7.1.4
Compressor
Maintenance
.....................................................................................................
27
7.1.5
Oil
Level
Check
and
Oil
Change
.............................................................................................
27
7.1.6
Troubleshooting
Guide
..........................................................................................................
27