T-340
7–22
7. Examine compressor and service valves. Ensure that the O-ring is not stuck in the gland of the valve.
8. Discard the O-ring on the O-ring face seal connection.
7.20.2
Installing the DUV:
1. Lubricate the gland shoulder area and O-ring with refrigerant oil.
2. Fit new valve in position and hand-tighten the O-ring nut.
3. Use a wet rag to keep valve cool while brazing. Braze DUV to service valve connection.
4. Reinstall and tighten the brackets that secure the valve body to the discharge line.
5. Torque O-ring face seal connections to 18 to 20 ft-lbs.
6. Install the coil onto the valve body and tighten the attachment bolt.
NOTE
Confirm that the small spacer tube is inserted into the coil prior to attaching it to the valve body. The valve
will not function correctly without it.
7. Leak check and evacuate low side of unit as applicable (see
).
8. Open service valves.
7.21 Valve Override Controls
Controller function code Cd41 is a configurable code that allows timed operation of the automatic valves for trou
-
bleshooting. Test sequences are provided in
. Capacity mode (CAP) allows alignment of the economizer
solenoid valve in the standard and economized operating configurations. DUV Capacity Modulation,% Setting
(PCnt) and Electronic Expansion Valve (EEV) allows opening of the digital unloader valve and electronic expansion
valve, respectively, to various percentages. If the unit is equipped with an LIV, the Liquid Valve Setting allows the
LIV to be automatically controlled, or manually opened and closed.
The Override Timer (tIM) selection is also provided to enter a time period of up to five minutes, during which the
override(s) are active. If the timer is active, valve override selections will take place immediately. If the timer is not
active, changes will not take place for a few seconds after the timer is started.When the timer times out, the override
function is automatically terminated and the valves return to normal machinery control. To operate the override:
1. Press the CODE SELECT key then press an Arrow key until Cd41 is displayed in the left window. The right
window will display a controller communications code.
2. Press the ENTER key. The left display will show a test name alternating with the test setting or time remain
-
ing. Use an Arrow key to scroll to the desired test. Press the ENTER key, SELCt will appear in the left dis
-
play.
3. Use an Arrow key to scroll to the desired setting, and then press the ENTER key. Selections available for
each of the tests are provided in
.
4. If the timer is not operating, follow the above procedure to display the timer. Use an Arrow key to scroll to the
desired time interval and press ENTER to start the timer.
5. The above described sequence may be repeated during the timer cycle to change to another override.
