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035-20401-001 Rev. A (0904)

Unitary Products Group

7

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, its 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 pro-
vided in unit literature packet for charge requirements.

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 than15 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 subcooling charging method whenever additional
refrigerant is required for the system charge. A superheat charging
method is not suitable for TXV equipped systems.

Measurement Method

If a calibrated charging cylinder or accurate weighing device is avail-
able, add refrigerant accordingly.

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

Subcooling Charging Method

For the 

heating operation

, there is no accurate subcooling method for

charging the unit. If unit charging is required during heating operation,
the unit must be evacuated and charge weighed-in per the marking on
the rating plate.

For the 

cooling operation

, the recommended subcooling is typically

around 10°F. This may vary greatly based on each unique syatem.

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 12 on the
last page of this document.

6.

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

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
12 for R-410A saturation temperatures.

See Tables 13 - 16 for unit specific subcooling charts.

See Figure 10 to trace the flow of refrigerant through the system.

R-410A refrigerant cylinders are rose colored, and have a dip tube
which allows liquid to flow out of the cylinder in the 

Upright Posi-

tion.

 Always charge the system slowly with the tank in the upright

position.

Do not leave the system open to the atmosphere.  Unit damage
could occur due to moisture being absorbed by the POE oil in the
system.  This type of oil is highly susceptible to moisture absorp-
tion.

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.

Example: The pressure P and temperature T measured at the liquid 
service port is 360 Psig and 93°F. From Table 12, the saturated tem-
perature for 360 Psig is 109°. The subcooling temperature TC = 
109°-93°=16°F

 FIGURE 10: 

Heat Pump Flow Diagram

.

TXV
(Cooling)

SHOWN IN COOLING POSITION.

COOLING CYCLE FLOW

HEATING CYCLE FLOW

INDOOR COIL

4-WAY
REVERSING
VALVE

SUCTION
ACCUMULATOR

COMPRESSOR

OUTDOOR
COIL

FIELD CONNECTED LINE

FILTER DRYER
(Solid core)

LIQUID
SENSOR

FIELD CONNECTED LINE

TXV
(Heating)

Summary of Contents for HC5B Series

Page 1: ...ractices and hazards involving only property dam age Improper installation may create a condition where the operation of the product could cause personal injury or property damage Improper installatio...

Page 2: ...topped ground area the unit should be raised sufficiently above the roof or ground to avoid taking the accumulated layer of hot air into the outdoor unit Provide an adequate structural support ADD ON...

Page 3: ...a line will result in loss of capacity and other problems caused by insufficient refrigerant flow Slope horizontal vapor lines at least 1 every 20 feet toward the out door unit to facilitate proper oi...

Page 4: ...tem from the vapor service port connection After this con nection has cooled remove the nitrogen source from the liquid fit ting service port 7 Replace the Schrader core in the liquid and vapor valves...

Page 5: ...a vertical run the bulb should be located at least 16 inches from any bend and on the tub ing sides opposite the plane of the bend The bulb should be positioned with the bulb tail at the top so that t...

Page 6: ...hat a mini mum air flow of 325 cfm ton be supplied at all times CFM SELECTION BOARD SETTINGS For proper system operation the CFM Selection Board jumpers must be set properly Refer to the Tabular Data...

Page 7: ...operation the unit must be evacuated and charge weighed in per the marking on the rating plate For the cooling operation the recommended subcooling is typically around 10 F This may vary greatly base...

Page 8: ...ys that are already energized but will not energize any additional relays until the voltage level increases If the voltage drops below approximately 16 VAC the control will imme diately de energize th...

Page 9: ...not be displayed when a fault code is present During the following conditions the control will not energize the X L out put FAULT CODE DISPLAY X L Output The X L terminal of the heat pump control is...

Page 10: ...ored fault codes from the control s memory This practice will enable better troubleshooting and diagnosis of system problems If the stored fault codes are not cleared after the cause of the problem ha...

Page 11: ...be removed and reapplied When the hard lockout condition is reset the control will de energize the LED and X L outputs and respond to thermostat inputs normally Wiring or Setting Related Lockouts The...

Page 12: ...ing cycle The control will initiate a defrost cycle every 6 hours accumulated com pressor run time to recirculate refrigerant lubricants This forced defrost timer will be reset and restarted following...

Page 13: ...es Recycling 24VAC to the control Shorting the TEST input pins If the Y2 LOCK jumper is in the OFF position the control will not imple ment second stage anticipation mode This results in second stage...

Page 14: ...uid line temperature Therefore if the control energizes Y2 OUT because the outdoor ambient temperature is greater than or equal to 50F or because the liquid line temperature exceeds the curve for the...

Page 15: ...ode If the other exit conditions are met while the unit is in defrost mode the control will complete the defrost cycle and then exit the forced second stage feature During defrost operation the contro...

Page 16: ...re is greater than the bal ance point setting the control will not energize the auxiliary heat out puts However the control shall ignore the balance point setting and energize auxiliary heat under som...

Page 17: ...t the control will de energize the compressor outputs and energize W1 OUT and W2 OUT immediately Table 11 describes the auxiliary heat operation for fossil fuel mode Bonnet Sensor Fossil Fuel Mode The...

Page 18: ...this document for detailed information The Y2 Lock jumper on the control is shown in figures 11 14 The fac tory places the Y2 Lock jumper in the ON position If the jumper is removed the control will...

Page 19: ...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...

Page 20: ...404 11 105 412 6 416 9 426 12 431 11 110 441 7 445 9 454 12 458 11 115 471 8 475 10 482 12 487 11 120 503 9 507 10 512 11 516 11 125 536 10 540 10 543 11 546 10 TABLE 15 15Z48HP Subcooling Charging C...

Page 21: ...035 20401 001 Rev A 0904 Unitary Products Group 21 SECTION X WIRING DIAGRAM FIGURE 15 Wiring Diagram...

Page 22: ...035 20401 001 Rev A 0904 22 Unitary Products Group NOTES...

Page 23: ...035 20401 001 Rev A 0904 Unitary Products Group 23...

Page 24: ...ct to change without notice Printed in U S A 035 20401 001 Rev A 0904 Copyright by York International Corp 2004 All rights reserved Supersedes Nothing Unitary 5005 Norman Product York OK Group Drive 7...

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