TWA-SVX01A-EN
13
Note:
For tubing over 40 ft. calculate the additional
refrigerant needed, based on notes above.
Gaseous Charging
This procedure is accomplished with the unit operating.
Electrical connections must be complete. Do not proceed
until the system is ready to operate.
Procedure
1. Connect R-22 drum with gauge manifold to the Schrader
valves (pressure taps) on the compressor discharge and
suction lines (Figure 6).
Note:
The compressor access panel must be installed
when the unit is running and being charged. The control
box access panel must be removed, and the manifold
hoses must be routed through an opening located in
the
bottom front of the control box. The opening has a pivoted
cover plate.
USE EXTREME CAUTION
WHILE SERVICING THE UNIT WHEN THE CONTROL
BOX ACCESS PANEL IS REMOVED AND POWER IS
APPLIED TO THE UNIT. FAILURE TO OBSERVE ALL
SAFETY PRECAUTIONS COULD RESULT IN SEVERE
PERSONAL INJURY OR DEATH.
!
2. Turn on power to the unit. Allow the system to run for five to
ten minutes to stabilize operating conditions.
3. Measure airflow across the indoor coil. Compare the mea-
surements with the fan performance data in the Data/Sub-
mittal or Service Facts. Once proper airflow is established,
observe the suction and head pressure gauges on the
gauge manifold. Pressure reading should fall approxi-
mately at the points shown by the pressure curves in Ser-
vice Facts. Add or remove refrigerant (gas only) as re-
quired to obtain correct head and suction pressures.
Check suction line superheat and condenser subcooling to
ensure the unit is operating properly.
4. Disconnect all power to the unit.
5. Remove the charging system from the unit and close the
opening in the bottom of the control box with the pivotal
cover before attempting to replace access panel.
6. Replace all panels.
Electrical Wiring
TWA field wiring consists of providing power supply to the
unit, installing the system indoor thermostat and providing
low voltage system interconnecting wiring. Access to elec
trical connection locations is shown in Figure 1, Figure 2 and
Figure 3.
Unit Power Supply
The installer must provide line voltage circuit(s) to the unit
main power terminals as shown by the unit wiring diagrams in
Service Facts or field wiring. Power supply must include a
disconnect switch in a location convenient to the unit. Ground
the unit according to local codes and provide flexible conduit if
codes require and/or if vibration transmission may cause noise
problems.
Important:
All wiring must comply with applicable local
and national
(NEC)
codes. Type and location of
disconnect switches must comply with all applicable
codes.
CAUTION:
Use copper conductors only. Unit terminals
are not designed for use with aluminum conductors. Use
of improper wiring materials can result in equipment
damage.
OPEN THE ELECTRICAL
DIS-CONNECT SWITCH AND LOCK IN OPEN
POSITION TO PREVENT ACCIDENTAL POWER
APPLICATION. FAILURE TO DO SO MAY RESULT IN
PERSONAL INJURY OR DEATH DUE TO ELECTRICAL
SHOCK.
Determine proper wire sizes and unit protective fusing
requirements by referring to the unit nameplate and/or the
unit Service Facts. Field wiring diagrams for accessories
are shipped with the accessory.
Low Voltage Wiring
Mount the indoor thermostat in accordance with the
thermostat installation instructions. Install color-coded,
weather-proof, multi-wire cable according to the
Interconnecting Wiring diagrams in the Air Handler IOM.
Installation
