Carrier AquaForce 30XV140, Controls, Start-Up, Operation, Service And Troubleshooting Instructions

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to either 0% or 100% will add an additional 160 steps to the
move, to ensure the valve is open or closed completely.
Follow the steps below to diagnose and correct EXV problems.
Check EXV motor operation first. Switch the Enable-Off-Re-
mote (EOR) Contact switch to the Off position.
Check the appropriate circuit EXV, EXV Position Circuit A %
Open ( Main Menu

Quick Test

Circuit A EXV Position )
or EXV Position Circuit B % Open ( Main Menu

Mainte-
nance Menu

EXV Control ). Use Quick Test procedure on
page 226. The current value of 0 will be displayed. Increase the
EXV position to select 100% valve position. The actuator
should be felt moving through the EXV. To close the valve, se-
lect 0%. The actuator should knock when it reaches the bottom
of its stroke.
If the valve is not working properly, continue with the follow-
ing test procedure:
1. Check the EXV output signals at appropriate terminals on
SIOB-A (J17-STPR1) and SIOB-B (J17-STPR1). Refer to
Tables 7 and 8 for additional information.
2. Connect positive test lead to SIOB(X)-J17 terminal 12V for
EXV(X) and SIOB(X)-J18 terminal 12V for economizer
EXV(X). Using the Quick Test procedure on page 226,
move the valve output under test to 100%. DO NOT short
meter leads together or pin 12V to any other pin, as board
damage will occur. During the next several seconds, careful-
ly connect the negative test lead to pins A,B,C and D in suc-
cession. Digital voltmeters will average this signal and dis-
play approximately 6 vdc. If the output remains at a constant
voltage other than 6 vdc or shows 0 volts, remove the con-
nector to the valve and recheck.
3. Select 0% to close the valve.
NOTE: The output is 12 vdc from the SIOB when the valve is
stationary.
If a problem still exists, replace the SIOB. If the reading is cor-
rect, the expansion valve and EXV wiring should be checked.
Check the EXV connector and interconnecting wiring.
1. Check color-coding and wire connections. Make sure they
are connected to the correct terminals at the EXV board and
EXV plug and that the cables are not crossed.
2. Check for continuity and tight connection at all pin terminals.
Check the resistance of the EXV motor windings. Remove the
EXV module plug SIOB(X)-J17 for main EXV and SIOB(X)-
J18 for economizer EXV. Check the resistance of the two
windings between pins A and C for one winding and pins B
and D for the other winding. The resistance should be 52 ohms
(± 5.2 ohms). Also check pins A-D for any shorts to ground.
Inspecting/Opening Electronic Expansion Valves
To check the physical operation of an EXV, the following steps
should be performed. Charge not isolated within the unit must
be recovered using proper refrigerant recovery techniques.
1. Isolate refrigerant within the chiller and recover remain-
ing charge. This will allow access to internal EXV com-
ponents. Closing the valves will minimize the amount of
refrigerant that will need to be removed.
For units without isolation valve option: Close the liquid
line ball valve directly above the filter drier as well as the
discharge line ball valves (see the Actuated Ball Valve
section on page 55 for instructions). Remove any remain-
ing refrigerant from the system low side using proper re-
covery techniques. The evaporator liquid line inlet has an
access port that can be used to remove charge from the
evaporator. The economizer assembly has a 1 /
4
-in. access
connection which can be used to remove charge from the
inlet of the EXVs. Turn off the line voltage power supply
to the compressors.
For units with isolation valve option: Close the ball valves
on the liquid line directly above the filter drier, after the main
EXV before the evaporator, and on the economizer line to
the compressor. Remove any remaining refrigerant from the
economizer assembly using proper recovery techniques. The
economizer assembly has a 1 /
4
-in. access connection which
can be used to remove charge from the inlet of the EXVs.
Turn off the line voltage power supply to the compressors.
2. The expansion valve motor is hermetically sealed inside the
top portion of the valve. See Fig. 60. Disconnect the EXV
plug. Carefully unscrew the motor portion from the body of
the valve. The EXV operator will come out with the motor
portion of the device. Reconnect the EXV plug.
3. Enter the appropriate EXV test step under the Test mode
( Main Menu

Quick Test Table ). Locate the desired pa-
rameter for the Main EXVs: Circuit A EXV Position, Circuit
B EXV Position or Economizer EXVs: EXV Eco Position
Cir A, EXV Eco Position Cir B. Change the position to
100%. Observe the operation of the lead screw. See Fig. 60.
Motor actuator movement should be smooth and uniform
from fully closed to fully open position. Select 0% and check
open to closed operation. If the valve is properly connected
to the processor and receiving correct signals, yet does not
operate as described above, the sealed motor portion of the
valve should be replaced.
Installing EXV Motor
If re-installing the motor, be sure to use a new gasket in the as-
sembly. See Fig. 61. It is easier to install the motor assembly
with the piston in the fully closed position. Insert the motor into
the body of the EXV. Tighten the motor to the body to 36 ft-lb
(50 N-m) and then tighten the valve another 30 degrees.
Moisture Liquid Indicator
Clear flow of liquid refrigerant indicates sufficient charge in sys-
tem. Bubbles in the sight glass indicate undercharged system or
presence of noncondensables. Moisture in system, measured in
parts per million (ppm), changes color of indicator. See Table 41.
Change filter drier at first sign of moisture in system.
Filter Drier
Whenever moisture-liquid indicator shows presence of mois-
ture, replace filter drier(s). There is one filter drier assembly on
each circuit with two cores. Refer to the Carrier Standard Ser-
vice Techniques Manual, Chapter 1, Refrigerants, for details on
servicing filter driers.
CAUTION
Do not remove EXV cables from the SIOB with the power
applied to the board. Damage to the board may occur.
IMPORTANT: Obtain replacement gaskets before open-
ing EXV. Do not re-use gaskets.
CAUTION
Ensure refrigerant is removed from both the inlet and outlet
of EXV assemblies. Equipment damage could result.
IMPORTANT: Obtain replacement gasket before opening
EXV. Do not re-use gaskets.
IMPORTANT: Unit must be in operation at least 12 hours
before moisture indicator can give an accurate reading.
With unit running, indicating element must be in contact
with liquid refrigerant to give true reading.