Carrier 25HCR installation instructions Care and Maintenance

25HCR

STEP 12 —Check Charge

Factory charge and charging method are shown on unit rating plate. To check charge in cooling mode, refer to Cooling Only Procedure. To check charge in heating mode, refer to Heating Check Chart Procedure.

Cooling Only Procedure

NOTE: If subcooling charging conditions are not favorable, charge must be weighed in accordance with unit rating plate,

±0.6 oz./ft. of 3/8-in. liquid line above or below 15 ft., respectively. Favorable conditions fall within the ranges given on the charging chart on the outdoor unit plate.

This system requires charging by the subcooling method.

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

2.Measure liquid service valve pressure by attaching an accurate gage to service port.

3.Measure liquid line temperature by attaching an accurate thermistor type or electronic thermometer to liquid line near outdoor coil.

4.Refer to unit rating plate for required subcooling temperature.

5.Refer to Table 3. Find the point where required subcooling temperature intersects measured liquid service valve pressure.

6.To obtain required subcooling temperature at a specific liquid line pressure, add refrigerant if liquid line temperature is higher than indicated or reclaim refrigerant if temperature is lower. Allow a tolerance of ± 3°F.

Heating Check Chart Procedure

To check system operation during heating cycle, refer to the Heating Check Chart on outdoor unit. This chart indicates whether a correct relationship exists between system operating pressure and air temperature entering indoor and outdoor units. If pressure and temperature do not match on chart, system refrigerant charge may not be correct. Do not use chart to adjust refrigerant charge.

STEP 13 —Final Checks

IMPORTANT: Before leaving job, be sure to do the following:

1.Ensure that all wiring is routed away from tubing and sh eet m etal ed g es to p rev en t ru b - th ro u g h o r w ire pinching.

2.Ensure that all wiring and tubing is secure in unit before adding panels and covers. Securely fasten all panels and covers.

3.Tighten service valve stem caps to 1/12-turn past finger tight.

4.L eav e U sers M an u al w ith o w n er. E x p lain sy stem operation and periodic maintenance requirements outlined in manual.

5.Fill out Dealer Installation Checklist and place in customer file.

Table 3—Required Liquid-Line Temperature

Liquid
Pressure	Required Subcooling Temperature (°F)
at Service
Valve
(PSIG)	5	10	15	20
134	71	66	61	56
141	74	69	64	59
148	77	72	67	62
156	80	75	70	65
163	83	78	73	68
171	86	81	76	71
179	89	84	79	74
187	92	87	82	77
196	95	90	85	80
205	98	93	88	83
214	101	96	91	86
223	104	99	94	89
233	107	102	97	92
243	110	105	100	95
253	113	108	103	98
264	116	111	106	101
274	119	114	109	104
285	122	117	112	107
297	125	120	115	110
309	128	123	118	113
321	131	126	121	116
331	134	129	124	119
346	137	132	127	122
359	140	135	130	125

CARE AND MAINTENANCE

For continuing high performance and to minimize possible equipment failure, periodic maintenance must be performed on this equipment.

Frequency of maintenance may vary depending upon geographic areas, such as coastal applications. See Users Manual for information.

Copyright 2006 Carrier Corp. S 7310 W. Morris St. S Indianapolis, IN 46231	Printed in U.S.A.	Edition Date: 02/06	Catalog No: 25HCR-2SI
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.			Replaces: 25HCR--1SI

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