Care And Maintenance - Carrier R-22 Application Manual And Service Manual

OUTDOOR TEMP (°F)
55
60
65
70
75
80
85
90
95
100
105
110
115
Where a dash appears, do not attempt to charge system under these conditions or refrigerant slugging may occur.
7. Locate superheat temperature located in previous step and
vapor pressure in Table 23. At this intersection note vapor-line
temperature.
8. If unit has a higher vapor-line temperature than charted
temperature, add refrigerant until charted temperature is
reached.
9. If unit has a lower vapor-line temperature than charted
temperature, bleed refrigerant until charted temperature is
reached.
10. If outdoor-air temperature or pressure at vapor valve changes,
charge to new vapor-line temperature indicated on chart.
SUBCOOLING CHARGING METHOD
1. Operate unit a minimum of 15 minutes before checking
charge.
2. Measure liquid service-valve pressure by attaching an accurate
gage to the service port.
3. Measure the liquid-line temperature by attaching an accurate
thermistor-type or electronic thermometer to the liquid line
near the outdoor coil.
4. Refer to unit-rating plate to find required subcooling tempera-
ture for units produced during or after January 1993. For units
produced through December 1992, refer to Table 24. Find the
point at which the required subcooling temperature intersects
the measured liquid service-valve pressure on Table 25.
5. To obtain the required subcooling temperature at a specific
liquid-line pressure, add refrigerant if liquid-line temperature
is higher than indicated or remove refrigerant if temperature is
lower. Allow a tolerance of 3°F.

CARE AND MAINTENANCE

To assure high performance and minimize possible equipment
malfunction, it is essential that maintenance be performed periodi-
cally on this equipment. The frequency with which maintenance is
performed is dependent on such factors as hours of operation,
geographic location, and local environmental conditions.
Table 22—Superheat Charging Table
INDOOR COIL ENTERING AIR TEMP (°F WET BULB)
50 52 54 56
9 12 14 17
7 10 12 15
— 6 10 13
— — 7 10
— — — 6
— — — —
— — — —
— — — —
— — — —
— — — —
— — — —
— — — —
— — — —
58 60 62 64
20 23 26 29
18 21 24 27
16 19 21 24
13 16 19 21
9 12 15 18
5 8 12 15
— — 8 11
— — 5 9
— — — 6
— — — —
— — — —
— — — —
— — — —
Disconnect all electrical power to unit before performing any
maintenance or service on outdoor unit. Remember to dis-
connect power supply to air handler as this unit supplies
low-voltage power to the outdoor unit. Electric shock can
cause personal injury or death.
The minimum maintenance that should be performed on this
equipment is as follows.
1. Check outdoor coil for cleanliness each month during the
heating (heat pump only) or cooling season and clean as
necessary, but clean at least once each heating (heat pump
only) and cooling season.
2. Check fan motor and blade for cleanliness each heating and
cooling season and clean as necessary.
3. Check electrical connections for tightness and controls for
proper operation each heating (heat pump only) or cooling
season and service as necessary.
Because of possible damage to the equipment or personal
injury, maintenance should be performed by qualified person-
nel only.
COIL CLEANING
1. Remove top cover. See Remove Top Cover section.
Coil fin damage can result in higher operating costs or
compressor damage. Do not use flame, high-pressure water,
steam, or volatile or corrosive cleaners on fins or tubing.
2. Clean coil using vacuum cleaner and its crevice tool. Move
crevice tool vertically, close to area being cleaned, making
sure tool touches only the dirt on the fins and not the fins. To
prevent fin damage, do not scrub fins with tool or move tool
horizontally against fins.
3. If oil deposits are present, spray coil with ordinary household
detergent. Wait 10 minutes, and proceed to next step.
4. Using garden hose, spray coil vertically downward with
constant stream of water at moderate pressure. Keep nozzle at
a 15° to 20° angle, about 3 in. from coil face and 18 in. from
tube. Spray so debris is washed out of coil and basepan.
46
66 68 70 72
32 35 37 40
30 33 35 38
27 30 33 36
24 27 30 33
21 24 28 31
18 21 25 28
15 19 22 26
13 16 20 24
10 14 18 22
8 12 15 20
5 9 13 17
— 6 11 15
— — 8 14
74 76
42 45
40 43
38 41
36 39
34 37
31 35
30 33
27 31
25 29
23 27
22 26
20 25
18 23