Q11-17. When the liquid line sight glass has a cloudy
duct pressure switch is located in the discharge air
or milky appearance, it is an indication that
plenum chamber.
which of the following conditions exists?
Q11-12. Which of the following statements best
1. That water is present in the system
describes the function of the compressor in an
2. The system pressure is too high
air-conditioning system?
3. The refrigerant is dirty and needs to be
1. It receives low-pressure refrigerant vapor
replaced
from the condenser and compresses it to
4. The level of refrigerant is low
such an extent that it liquefies in the
Q11-18. Where would you find a fusible plug in an
evaporator
air-conditioning system?
2. It receives low-pressure refrigerant vapor
from the evaporator and compresses it to
1.
In the receiver
such an extent that it liquefies in the
2.
In the pump
condenser
3.
In the liquid line
3. It receives low-pressure liquid from the
4.
In the expansion valve
receiver and circulates it throughout the
Q11-19. What is the purpose of the high- and
system
low-pressure cutouts in an air-conditioning
4. It receives low-pressure liquid from the
system?
expansion valve and circulates it to the
evaporator
1. To protect the condenser from low inlet
pressure and excessive discharge pressure
Q11-13. Which of the following components will
2. To protect the evaporator from low inlet
entrap the liquid refrigerant during the pump
pressure and excessive discharge pressure
down cycle?
3. To protect the compressor from low inlet
1.
The evaporator
pressure and excessive discharge pressure
2.
The condenser
4. To protect the receiver from low inlet
3.
The piping
pressure and excessive discharge pressure
4.
The receiver
Q11-14. Which of the following components is located
A/M32C-17 TRAILER-MOUNTED
between the high-pressure side and the
AIR-CONDITIONING UNIT
low-pressure side of the system and meters
LEARNING OBJECTIVES: Identify pro-
the amount of refrigerant that flows into the
cedures for inspecting, checking, testing, and
evaporator?
adjusting air-conditioner components. Identify
1.
The expansion valve
procedures for troubleshooting and repairing
2.
The heat exchanger
air-conditioner components.
3.
The flow control valve
There are two primary mobile air-conditioners in
4.
The regulator
use in the fleet today, the A/M32C-17 and the
Q11-15. What part of the expansion valve is attached
A/M32C-21. The A/M32C-21 (fig. 11-18) is
to the diaphragm housing by a small tube?
electric-powered and is used both ashore and afloat.
The A/M32C-17 (fig. 11-19) is diesel-powered and is
1.
The thermometer
used ashore only. The units are similar in many ways,
2.
The metering bulb
so we have chosen to focus primarily on the
3.
The thermobulb
A/M32C-17 in this course. For information on the
4.
The pressure regulator
A/M32C-21, see AG-180AO-MMM-000.
Q11-16. What is the state of the refrigerant when it
The A/M32C-17 is a mobile self-contained unit
exits the evaporator?
that consists primarily of a diesel engine drive system,
1.
A hot vapor at low pressure
refrigeration system, ventilating system, hydraulic
2.
A cool vapor at low pressure
system, and control system. This unit is enclosed in a
3.
A super-heated vapor at high pressure
trailer-mounted metal housing. The trailer is suitable
4.
A super-heated vapor at low pressure
for towing behind a military vehicle.
11-18
