1-1/2 Ton Subcooling Charging Chart; System Start-Up - York International CMB SERIES Installation Manual

163911-UIM-A-0106
Subcooling Charging Method
For the cooling operation, 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 1.
6. Subcooling temperature TC = Saturated Temperature (ST) - Liquid
Temp (T).
Example: The pressure P and temperature T measured at the liquid
service port is 228 Psig and 101 °F. From Table 1, the saturated tem-
perature for 228 Psig is 110.5°. The subcooling temperature TC =
110.5°-101°=9.5°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 1
for R-22 saturation temperatures.
See Tables 2-7 for unit specific subcooling charts.
SECTION VIII: SYSTEM START-UP
ENERGIZE CRANKCASE HEATER
If this unit is equipped with a crankcase heater for the compressor, a
warning label with an adhesive back is supplied in the unit installation
instruction packet. This label should be attached to the field supplied
disconnect switch where it will be easily seen.
In order to energize the crankcase heater, set the indoor cooling ther-
mostat to the "OFF" position. Close the line power disconnect to the
unit.
IMPORTANT: An attempt to start the compressor without at least 8
hours of crankcase heat will damage the compressor.
WITH POWER TO UNIT AND THERMOSTAT IN COOLING POSITION.
1. In the cooling cycle, discharge gas is pumped to the outdoor coil
which is the condenser. The indoor coil is the evaporator.
2. If fan switch is in "ON" position, a circuit is made through blower
relay to provide continuous blower operation.
3. With fan switch in "AUTO" position, a circuit is made from thermo-
stat cooling contact through blower relay to provide blower opera-
tion.
4. System will cycle with thermostat demand to provide cooling as
needed.
INDICATIONS OF PROPER OPERATION
Cooling
1. The outdoor fan should be running, with warm air being dis-
charged from the top of the unit.
2. The indoor blower (furnace or air handler) will be operating, dis-
charging cool air from the ducts. Coils or other parts in the air cir-
cuit should be cleaned as often as necessary to keep the unit
clean. Use a brush, vacuum cleaner attachment, or other suitable
means.
3. The vapor line at the outdoor unit will feel cool to the touch.
4. The liquid line at the outdoor unit will feel warm to the touch.
8
Instructing the Owner
Assist owner with processing warranty cards and/or online registration.
Review Owners Guide and provide a copy to the owner and guidance
on proper operation and maintenance. Instruct the owner or the opera-
tor how to start, stop and adjust temperature setting.
When applicable, instruct the owner that the compressor is equipped
with a crankcase heater to prevent the migration of refrigerant to the
compressor during the "OFF" cycle. The heater is energized only when
the unit is not running. If the main switch is disconnected for long peri-
ods, do not attempt to start the unit until 8 hours after the switch has
been connected. This will allow sufficient time for all liquid refrigerant to
be driven out of the compressor.
The installer should also instruct the owner on proper operation and
maintenance of all other system components.
Maintenance
1. Dirt should not be allowed to accumulate on the outdoor coils or
other parts in the air circuit. Clean as often as necessary to keep
the unit clean. Use a brush, vacuum cleaner attachment, or other
suitable means.
2. The outdoor fan motor is permanently lubricated and does not
require periodic oiling.
3. If the coil needs to be cleaned, it should be washed with Calgon
Coilclean (mix one part Coilclean to seven parts water). Allow
solution to remain on coil for 30 minutes before rinsing with clean
water. Solution should not be permitted to come in contact with
painted surfaces.
4. Refer to the furnace or air handler instructions for filter and blower
motor maintenance.
5. The indoor coil and drain pan should be inspected and cleaned
regularly to prevent odors and assure proper drainage.
IT IS UNLAWFUL TO KNOWINGLY VENT, RELEASE OR DIS-
CHARGE REFRIGERANT INTO THE OPEN AIR DURING
REPAIR, SERVICE, MAINTENANCE OR THE FINAL DISPOSAL
OF THIS UNIT.
WHEN THE SYSTEM IS FUNCTIONING PROPERLY AND THE
OWNER HAS BEEN FULLY INSTRUCTED, SECURE THE
OWNER'S APPROVAL.
TABLE 1: 1-1/2 Ton Subcooling Charging Chart
Outdoor
Ambient
57
DB (°F) Liquid Pressure (psig) at Base Valve
65 136 (7)
70 149 (8)
75 162 (9)
80 176 (9)
85 191 (9)
90 205 (9)
95 221 (9)
100 236 (9)
105 253 (9)
110 269 (9)
115 286 (9)
120 304 (8)
125 322 (8)
Indoor Wet Bulb (°F)
62 67 72
137 (7) 139 (7) 142 (7)
150 (8) 152 (8) 155 (8)
163 (9) 165 (9) 168 (9)
177 (9) 179 (9) 182 (9)
192 (9) 194 (9) 197 (9)
206 (9) 208 (9) 211 (9)
222 (9) 224 (9) 227 (9)
237 (9) 239 (9) 242 (9)
254 (9) 256 (9) 259 (9)
270 (9) 272 (9) 275 (9)
287 (9) 289 (9) 292 (9)
305 (8) 307 (9) 310 (9)
323 (8) 325 (9) 328 (8)
Unitary Products Group