Bryant R-22 service manual Superheatcharging Table, Requiredvapor Temperature F

TABLE 21—SUPERHEAT CHARGING TABLE

OUTDOOR TEMP (°F)							INDOOR COIL ENTERING AIR TEMP (°F WET BULB)
	50	52		54		56		58		60	62	64	66	68	70	72	74	76
55	9	12		14		17		20		23	26	29	32	35	37	40	42	45
60	7	10		12		15		18		21	24	27	30	33	35	38	40	43
65	—	6		10		13		16		19	21	24	27	30	33	36	38	41
70	—	—		7		10		13		16	19	21	24	27	30	33	36	39
75	—	—	—			6		9		12	15	18	21	24	28	31	34	37
80	—	—	—		—			5		8	12	15	18	21	25	28	31	35
85	—	—	—		—		—		—		8	11	15	19	22	26	30	33
90	—	—	—		—		—		—		5	9	13	16	20	24	27	31
95	—	—	—		—		—		—	—		6	10	14	18	22	25	29
100	—	—	—		—		—		—	—	—		8	12	15	20	23	27
105	—	—	—		—		—		—	—	—		5	9	13	17	22	26
110	—	—	—		—		—		—	—	—	—		6	11	15	20	25
115	—	—	—		—		—		—	—	—	—	—		8	14	18	23

Where a dash appears, do not attempt to charge system under these conditions or refrigerant slugging may occur.

TABLE 22—REQUIRED VAPOR TEMPERATURE (°F)

SUPERHEAT TEMP			VAPOR PRESSURE AT SERVICE PORT (PSIG)
(°F)	61.5	64.2	67.1	70.0	73.0	76.0	79.2	82.4	85.7
0	35	37	39	41	43	45	47	49	51
2	37	39	41	43	45	47	49	51	53
4	39	41	43	45	47	49	51	53	55
6	41	43	45	47	49	51	53	55	57
8	43	45	47	49	51	53	55	57	59
10	45	47	49	51	53	55	57	59	61
12	47	49	51	53	55	57	59	61	63
14	49	51	53	55	57	59	61	63	65
16	51	53	55	57	59	61	63	65	67
18	53	55	57	59	61	63	65	67	69
20	55	57	59	61	63	65	67	69	71
22	57	59	61	63	65	67	69	71	73
24	59	61	63	65	67	69	71	73	75
26	61	63	65	67	69	71	73	75	77
28	63	65	67	69	71	73	75	77	79
30	65	67	69	71	73	75	77	79	81
32	67	69	71	73	75	77	79	81	83
34	69	71	73	75	77	79	81	83	85
36	71	73	75	77	79	81	83	85	87
38	73	75	77	79	81	83	85	87	89
40	75	77	79	81	83	85	87	89	91

a TXV, the subcooling method must be used. Heat pumps must be operating in the cooling mode. To charge by superheat, a service technician needs an accurate superheat thermocouple or thermistor-type thermometer, a sling psychrometer, and a gage manifold. Do not use mercury or small-dial-type thermometers as they are not adequate for this type of measurement. Then use 1 of the following procedures:

SUPERHEAT CHARGING METHOD

1.Operate a unit a minimum of 10 minutes before checking charge.

2.Measure vapor pressure by attaching a gage to vapor valve-service port.

3.Measure vapor-line temperature by attaching a service thermometer to unit vapor line near vapor valve. On a heat pump, attach to the suction tube between the accumulator and the compressor. Insulate thermometer for accurate readings.

4.Measure outdoor-air, dry-bulb temperature with a second thermometer.

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5.Measure indoor-air (entering indoor coil), wet-bulb tem- perature with a sling psychrometer.

6.Locate outdoor temperature and evaporator entering air wet-bulb temperature in Table 21. At this intersection note the superheat.

7.Locate superheat temperature located in previous step and vapor pressure in Table 22. 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.