Johnson Controls 13 SEER installation manual Section V Installations Requiring AN ADD-ON TXV KIT

347337-UIM-A-0408

SECTION V: INSTALLATIONS REQUIRING AN ADD-ON TXV KIT

For installations requiring a TXV kit, refer to the Installation Instructions accompanying the TXV kit.

Schrader valve core MUST NOT be installed with TXV installation. Poor system performance or system failure could result.

SECTION VI: EVACUATION

It will be necessary to evacuate the system to 500 microns or less. If a leak is suspected, leak test with dry nitrogen to locate the leak. Repair the leak and test again.

To verify that the system has no leaks, simply close the valve to the vac- uum pump suction to isolate the pump and hold the system under vac- uum. Watch the micron gauge for a few minutes. If the micron gauge indicates a steady and continuous rise, it’s an indication of a leak. If the gauge shows a rise, then levels off after a few minutes and remains fairly constant, it’s an indication that the system is leak free but still con- tains moisture and may require further evacuation if the reading is above 500 microns.

SECTION VII: SYSTEM CHARGE

The factory charge in the outdoor unit includes enough charge for the unit, a 15 ft. line set, and the smallest indoor coil match-up. Some indoor coil matches may require additional charge. See tabular data sheet provided in unit literature packet for charge requirements.

Do not leave the system open to the atmosphere.

The “TOTAL SYSTEM CHARGE” must be permanently stamped on the unit data plate.

Total system charge is determined as follows:

1.Determine outdoor unit charge from tabular data sheet.

2.Determine indoor coil adjustment from tabular data sheet.

3.Calculate the line charge using the tabular data sheet if line length is greater than 15 feet.

4.Total system charge = item 1 + item 2 + item 3.

5.Permanently stamp the unit data plate with the total amount of refrigerant in the system.

Use the following charging method whenever additional refrigerant is required for the system charge.

Refrigerant charging should only be carried out by a qualified air conditioning contractor.

Compressor damage will occur if system is improperly charged. On new system installations, charge system per tabular data sheet for the matched coil and follow guidelines in this instruction.

If a calibrated charging cylinder or accurate weighing device is avail- able, add refrigerant accordingly. Otherwise, model-specific charging charts are provided on the access panel of the unit. If mix matched TXV indoor coils are used with these models, the following subcooling charg- ing method must be used. Superheat charging charts are not valid with TXV equipped systems.

SUBCOOLING CHARGING METHOD - MIXED MATCH COILS

The recommended subcooling is 10°F

1.Set the system running in the cooling mode by setting the thermo- stat at least 6°F below the room temperature.

2.Operate the system for a minimum of 15-20 minutes.

3.Refer to the tabular data sheet for the recommended airflow and verify this indoor airflow (it should be about 400 SCFM per ton).

4.Measure the liquid refrigerant pressure P and temperature T at the service valve.

5.Calculate the saturated liquid temperature ST from Table 2.

6.Subcooling temperature TC = Saturated Temperature (ST) - Liquid Temp (T).

Example: The pressure P and temperature T measured at the liq- uid service port is 196 psig and 90°F, respectlvely. From Table 2, the saturated temperature for 196 psig is 100°F. The subcooling temperature TC = 100°-90°=10°F

Add charge if the calculated subcooling temperature TC in Step 6 is lower than the recommended level. Remove and recover the refrigerant if the subcooling TC is higher than the recommended level. See Table 2.

Check flare caps on service ports to be sure they are leak tight. DO NOT OVERTIGHTEN (between 40 and 60 inch - lbs. maximum).

TABLE 2: R-22 Saturated Properties

Pressure	Temp °F	Pressure	Temp °F	Pressure	Temp °F	Pressure	Temp °F	Pressure	Temp °F	Pressure	Temp °F
PSIG		PSIG		PSIG		PSIG		PSIG		PSIG
80	48	110	64	140	78	170	91	200	101	230	111
82	49	112	65	142	79	172	91	202	102	232	112
84	50	114	66	144	80	174	92	204	103	234	112
86	51	116	67	146	81	176	93	206	103	236	113
88	52	118	68	148	82	178	94	208	104	238	114
90	54	120	69	150	83	180	94	210	105	240	114
92	55	122	70	152	84	182	95	212	105	242	115
94	56	124	71	154	84	184	96	214	106	244	115
96	57	126	72	156	85	186	97	216	107	246	116
98	58	128	73	158	86	188	97	218	107	248	117
100	59	130	74	160	87	190	98	220	108	250	117
102	60	132	75	162	88	192	99	222	109	252	118
104	61	134	76	164	88	194	99	224	109	254	118
106	62	136	77	166	89	196	100	226	110	256	119
108	63	138	78	168	90	198	101	228	111	258	119

Johnson Controls Unitary Products 5