Maytag Amana VZC20, Installation & Service Reference

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10
System Wiring
SYSTEM START-UP PROCEDURE
GENERAL NOTES:
Adequate refrigerant charge for the matching indoor coil
and 15 feet of line set is supplied with the heat pump unit. If
liquid line set exceeds 15 feet in length, refrigerant should
be added at 0.6 ounces per foot of liquid line.
Start-up Procedure Detail
Liquid and suction valves on heat pump unit are closed to
contain the charge within the unit. The unit is shipped with
the valve stems closed and caps installed. Do not open
valves until the indoor coil and line set is evacuated.
Step 1. Calculate Refrigerant Charge Based on
Line Set Length
The heat pump unit is shipped with a predetermined factory
charge level as shown in unit serial plate . For longer line
sets greater than 15 feet, add 0.6 ounces of refrigerant per
foot. Refer to the following page for the equivalent length
of the elbow fittings.
NOTICE
T
OTAL
R
EFRIGERANT
=
F
ACTORY
C
HARGE
+ ( 0.6
OZ
./
FT
. * A
DDITIONAL
F
EET
OF
A
CTUAL
L
INE
S
ET
).
Step 2. Connect Manifold Gauges to System
CAUTION
OPEN THE LIQUID VALVE FIRST! If the suction service valve
is opened first, oil from the compressor may be drawn into
the indoor coil or TXV restricting refrigerant flow and
affecting operation of the system.
POSSIBLE REFRIGERANT LEAK!
T
O AVOID A POSSIBLE REFRIGERANT LEAK
,
OPEN THE SERVICE VALVES
UNTIL THE TOP OF THE STEM IS
1 /8”
FROM THE RETAINER
.
CAUTION
E
NSURE VALVES ARE OPEN AND ADDITIONAL CHARGE IS ADDED
BEFORE APPLYING POWER
.
CAUTION
Type of
Elbow Fittings 3/4 7/8 1 1/8
90° short radius 1.7 2 2.3
90° long radius 1.5 1.7 1.6
45° 0.7 0.8 1
Inside Diameter (inches)
Note: The following table lists the equivalent length
gained from adding bends to the suction line.
Properly size the suction line to minimize capacity
After the refrigerant charge has bled into the system, open
the liquid service valve.
When opening valves with retainers, open each valve
only until the top of the stem is 1/8” from the retainer. To
avoid loss of refrigerant, DO NOT apply pressure to the
retainer. When opening valves without a retainer, remove
service valve cap and insert a hex wrench into the valve
stem and back out the stem by turning the hex wrench
counterclockwise. Open the valve until it contacts the rolled
lip of the valve body.
The service valve cap is the secondary seal for the valves
and must be properly tightened to prevent leaks. Make
sure cap is clean and apply refrigerant oil to threads and
sealing surface on inside of cap. Tighten cap finger-tight
and then tighten additional 1/6 of a turn to properly seat the
sealing surfaces.
Do not introduce liquid refrigerant from the cylinder into the
crankcase of the compressor (suction side) as this may
damage the compressor.
Break vacuum by fully opening liquid and gas base valve.
NOTE. Units may utilize ball valves or front
seating valves. These are not back-seating valves.
It is not necessary to force the stem tightly
against the rolled lip.