Evacuation - Amana V Series Service Manual

Service Procedures
To avoid risk of electrical shock, severe personal injury or death; disconnect power to unit before servicing, unless
testing requires power. Discharge capacitor through a 10,000 ohm resistor before handling. Wires removed during
disassembly must be placed on the correct terminals to ensure proper grounding and polarization.
Slight or partial restrictions can give the same symptoms
as refrigerant shortage, including lower-than-normal
back pressure, head pressure and wattage readings.
Inside the unit, temperatures are above normal.
Total restriction on the discharge side of the compressor
(when the restriction is between the compressor and the
first half of the condenser) results in higher-than-normal
head pressure and wattage while the low side is being
pumped out.
Testing for Restrictions
To determine if a restriction exists:
1. Attach gauge and manifold between suction and
discharge sides of sealed system.
2. Turn unit on and allow pressure on both sides to
stabilize. Inspect condenser side of system. Tubing
on condenser should be warm and temperature
should be equal throughout (no sudden drops at any
point along tubing).
• If temperature of condenser tubing is consistent
throughout, go to step 4.
• If temperature of condenser tubing drops suddenly
at any point, tubing is restricted at point of
temperature drop (if restriction is severe, frost
may form at point of restriction and extend down
in direction of refrigerant flow in system). Go to
step 5.
3. Visually check system for kink(s) in refrigeration
tubing that could cause the restriction. Correct
kink(s) and repeat step 2.
4. Turn unit off and determine how long it takes high-
pressure and low-pressure gauges to equalize:
• If pressure equalization takes longer than 10
minutes, a restriction exists in the capillary tube or
drier filter. Go to step 5.
• If pressure equalization takes less than 10
minutes, system is not restricted. Check for other
possible causes of malfunction.
5. Recover refrigerant in sealed system.
NOTE: Before opening any refrigeration system,
capture refrigerant for safe disposal.
6. Disconnect unit from power.
• Protect yourself by wearing goggles, gloves and
other personal protective equipment.
• Protect components by using heat-trap paste,
heat sinks and other means to isolate heat.
7. Remove and replace restricted device.
8. Evacuate and charge system per the following
instructions:
!
WARNING

Evacuation

Proper evacuation of a sealed refrigeration system is an
important service procedure. Usable life and operational
efficiency of a sealed system greatly depend upon how
completely air, moisture and other non-condensables
are evacuated.
Before opening system, evaporator coil must be at
ambient temperature to minimize moisture infiltration
into system.
NOTE: Before opening any refrigeration system, EPA
regulations require refrigerant in system to be
captured for safe disposal.
Procedure:
1. Connect vacuum pump, vacuum-tight manifold set
with high-vacuum hoses, thermocouple vacuum
gauge and charging cylinder as shown in illustration.
NOTE: Evacuation should be done through I.D. opening
of tubes and not through a line-piercing valve.
2. Connect low-side line to compressor process tube.
3. Connect high-side line to drier process tube.
4. Evacuate both sides simultaneously. With valves "C"
and "F" closed, open all other valves and start
vacuum pump.
Micron
Vacuum Gauge
Compressor
5. After compound gauge (low side) drops to
approximately 29 inches gauge, open valve "C" to
micron vacuum gauge and take micron reading.
NOTE: A high-vacuum pump can produce good
vacuum only if oil in pump is not contaminated.
Pumps contaminated from use with other
refrigerants must not be used on HFC134a
systems.
21
High Side Gauge
Low Side Gauge
D
E
Valve
Valve
C
Charging Hose
B
Compressor
Process
A
Tube
.6 cm Copper
Tubing
Vacuum Pump
Evacuation & Charging Setup
Drier/Process Tube
Charging Hose
F
Valve
Charging
Cylinder
RS1300004 Rev. 1