GPH16M Installation Manual

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c. If subcooling and superheat are high, adjust TXV valve superheat, then check subcooling.
d. If subcooling is high and superheat is low, adjust TXV valve superheat and remove charge to lower the subcooling.
NOTE: Do NOT adjust the charge based on suction pressure unless there is a gross undercharge.
4. Disconnect manifold set, installation is complete.
Refrigerant Charge Check (Units with Fixed Orifice Devices)
After completing airflow measurements and adjustments the unit’s refrigerant charge must be checked. All package units with
fixed orifice devices are charged using the super heat method at the compressor suction line.
After superheat is adjusted it is recommended to check unit sub-cooling at the condenser coil liquid line out. For charge adjustments,
see superheat and subcooling charts shown for each model.
SYSTEM CHARGING HEATING MODE
The proper method of charging a heat pump in the heat mode is by weighing the charge according to the total charge listed on the
rating plate.
Measure the hot gas discharge at the compressor to ensure proper TXV setting. To ensure optimum system performance in heat
mode, the TXV may require adjustment.
1. Allow the system to operate for at least 20 minutes.
2. Attach and insulate an electronic thermometer to the hot gas discharge
line mid-way between the compressor and the reversing valve.
NOTE: The thermometer must be well insulated to prevent ambient
influences.
3. Allow the compressor to operate for about 10 additional minutes and
measure the hot gas discharge temperature.
4. Using an additional electronic thermometer, measure the ambient
temperature.
5. Adjust the TXV until the hot gas temperature equals 100°F + ambient
temperature (+ or - 3°F). Close TXV to increase the temperature.
NOTE: When adjusting the TXV, allow the compressor to operate for
about 10 minutes before taking readings. Do not adjust TXV more
than 1/4 of a turn between readings.
SUCTION PRESSURE
SATURATED SUCTION
TEMPERATURE ºF
PSIG R-410A
50 1
52 3
54 4
56 6
58 7
60 8
62 10
64 11
66 13
68 14
70 15
72 16
74 17
76 19
78 20
80 21
85 24
90 26
95 29
100 31
110 36
120 41
130 45
140 49
150 53
160 56
170 60
SATURATED SUCTION PRESSURE
TEMPERATURE CHART
SUPERHEAT = SUCTION LINE TEMP - SAT. SUCTION TEMP
LIQUID PRESSURE
SATURATED LIQUID
TEMPERATURE ºF
PSIG R-410A
200 70
210 73
220 76
225 78
235 80
245 83
255 85
265 88
275 90
285 92
295 95
305 97
325 101
355 108
375 112
405 118
415 119
425 121
435 123
445 125
475 130
500 134
525 138
550 142
575 145
600 149
625 152
SATURATED LIQUID PRESSURE
TEMPERATURE CHART
SUBCOOLING = SAT. LIQUID TEMP. - LIQUID LINE TEMP.
Models Superheat °F Subcooling °F
GPH1624M41 15 ±2 8 ±2
GPH1630M41 15 ±2 10 ±2
GPH1636M41 13 ±2 10 ±2
GPH1642M41 15 ±2 10 ±2
GPH1648M41 15 ±2 13 ±2
Design Superheat & Subcooling
@ 95
°
F Outdoor Ambient Temperature
High Stage