Carrier 50WQ - Manual (Page 9)

#
#
COMPRESSOR DISCHARGE PRESSURE® SERVICE PORT (PSIG)
Fig. 16 — 50WQ042 Cooling Cycle
Charging Chart (R-22)
Fig. 17 — 50WQ042 Heating Cycle Operation
Check Chart (R-22)
6. Read evaporator temperature at red needle posi­
tion on Chargemaster temperature gage and
suction line temperature at black needle position.
CAUTION; i>o not read evaporator tem­
perature witfe Chargernaster valve open.
7. Enter 50WQ Chargemaster Charging Chart,
Table 5, at unit leaving water temperature (step 5)
and evaporator temperature (step 6). (Do not use
standard charging chart on cover of Charge-
master device.) Find the suction line temperature
required for correct system charge. If actual
suction line temperature (step 6) is higher than
table value, the system is undercharged. If
suction line temperature is lower than table
value, the system is overcharged.
Example: At leaving water temperature of 93 F
and evaporator temperature of 41 F, the system is
correctly charged at 50 F ( ± 2 F) suction line
temperature.
8. Add charge by slowly opening Chargemaster
valve. If necessary, reduce charge by bleeding at
liquid line Schrader valve. Check outdoor air and
evaporator temperature during procedure. If
they change, refer back to Chargemaster
Charging Chart for new value.
Correct use of Chargemaster device ensures that
an optimum refrigerant charge is in system when
conditions and system components are normal.
However, the device does not solve or fix system
abnormalities. It indicates correct charge for condi­
tion of system. It does not make corrections for dirty
filters, slow fans, or other abnormal conditions.
This charging device ensures that a correct relation­
ship exists between leaving water temperature, evap­
orator temperature, and suction line temperature on
a specific system.
CHARGEMASTER® DEVICE OPERATION —
Operate unit 10 minutes before using device. Ensure
unit indoor fan section access panel is in place for
proper Chargemaster operation.
1. Tape Chargemaster feeler bulb to unit suction
line. Insulate bulb. Ensure suction line is clean
for good contact with bulb.
2. Connect refrigerant drum to Chargemaster inlet
port with drum in position for vapor charging.
3. Connect Chargemaster outlet port (loosely) to
unit suction line Schrader valve.
4. Crack valves on refrigerant drum and Charge-
master device to purge lines from drum to suction
line Schrader valve. After purging lines, close
valve on Chargemaster device only. Tighten
Chargemaster
connection at suction line
Schrader valve.
5. Measure unit leaving water temperature.
Table 5 — Chargemaster Charging Chart
UNIT
LEAVING
WATER
TEMP
(F)
3o] 41 44
EVAPORATOR TEMP (F)
33_I ss J m 47 50 53 56
Suction Line Temperature (F)
" _
75
46
45*
49^
47
51
50
54
53
57
55
59
58
61
60 64
—
81 46 49 51 54 56 57 63
87 48 50 52 54 56 62 65
93 46 48 50 53 55 57 61
99 47 49 51 54 56 61 64
105 45 47 50 53 56 60 63
112 46 49 53 55 59 62
117 45 47 52 55 57 61
123 46 50 53 55 56
*Saturated evaporator temperature which is the equivalent tem­
perature of pressure taken at unit suction service valve.