LIQUID LINE SWIVEL COUPLING
(This fitting is a
ORIFICE
DISTRIBUTOR
FIGURE 5: Orifice Installation
SECTION V: TXV INSTALLATIONS
When using a TXV, models
The following are the basic steps for installation. For detailed instruc- tions, refer to the Installation Instructions accompanying the TXV kit. Install TXV kit as follows:
1.Relieve the holding charge by pulling off the rubber cap plug on the suction manifold line of the coil.
2.After holding charge is completely discharged, loosen and remove the schraeder cap seal.
3.Loosen and remove distributor cap seal.
4.Install the thermal expansion valve to the orifice distributor assem- bly with supplied fittings. Hand tighten and turn an additional 1/4 turn to seal. Do not overtighten fittings.
5.Install the liquid line to the top of the thermal expansion valve with fitting supplied with the liquid line. Hand modify the liquid line to align with casing opening. Hand tighten the liquid line and an addi- tional 1/4 turn to seal.
6.Install the TXV equalizer line into the vapor line as follows:
a.Hand tighten the 1/4” SAE nut to the schraeder fitting and an additional 1/3 turn to seal.
7.Install the TXV bulb to the vapor line near the equalizer line, using the bulb clamp(s) furnished with the TXV assembly. Ensure the bulb is making maximum contact.
a.Bulb should be installed on a horizontal run of the vapor line if possible. The bulb should be installed on top of the line.
b.If bulb installation is made on 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 the bulb acts as a reservoir.
c.Bulb should be insulated using thermal insulation provided to protect it from the effect of the surrounding ambient tempera- ture. Cover completely to insulate from
In all cases, mount the TXV bulb after vapor line is brazed and has had sufficient time to cool.
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
See tabular data sheet provided in unit literature packet for charge requirements. Each unit has been shipped from the factory with a nitro- gen holding charge and POE oil in the compressor.
This unit does not contain any refrigerant. It contains a nitrogen hold- ing charge. Operating this unit with the nitrogen holding charge will damage the compressor.
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 initial unit charge from tabular data sheet.
2.Calculate the line charge using the tabular data sheet if line length is greater than 15 feet.
3.Total system charge = item 1 + item 2.
4.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.
DO NOT attempt to pump “Total System Charge” into outdoor unit for maintenance, service, etc. This may cause damage to the compres- sor and/or other components. the outdoor unit only has enough vol- ume for the factory charge, not the “Total System Charge”.
Refrigerant charging should only be carried out by a qualified air con- ditioning 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,
Johnson Controls Unitary Products | 5 |
