Carrier NDK33BN0KB, Руководство по эксплуатации и обслуживанию

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62-61753-21 8-22
tor tester to manually open the valve to 100% before
it is installed. Torque nut to 47.4 Nm (35 ft-lb).
c. Leak check, evacuate the unit and charge in ac-
cordance with sections 8.5.2, 8.5.3 & 8.5.4.
Emergency Repair Procedures:
In the event that the SMV system has a failure, and
replacement components are not readily available in
an emergency. A
LIMP-HOME procedure can be done
as follows:
a. Attach a manifold gauge set.
b. Remove the refrigerant charge. (Refer to section
8.5.1).
c. Remove SMV power head by loosening the
2-1/8 inch diameter nut (see Figure 8-13), and slid-
ing the power head out.
d. Remove the piston by loosening the Allen screw and
removing the piston and screw.
e. Install the power head assembly (without piston),
torque to 47 to 54 Nm (35 to 40 ft-lb).
f. Leak check, evacuate the unit and charge in ac-
cordance with sections 8.5.2, 8.5.3 & 8.5.4.
g. Start the unit.
7. Adjust the suction service valve so that the approx-
imate temperature OR current limit is maintained.
For perishable loads, it is recommended that the ad-
justment be made so that the available capacity is
slightly larger than the load, the unit will cycle OFF
and ON.
h. Once repair parts become available, repair as re-
quired.
8.6.8 Electronic Expansion Valve
The electronic expansion valve (EVXV - see Figure
8-15) is an automatic device which maintains constant
superheat of the refrigerant gas leaving the evaporator
regardless of suction pressure. The valve functions
are: (a) automatic response of refrigerant flow to
match the evaporator load and (b) prevention of liquid
refrigerant return to the compressor. Unless the valve
is defective, it seldom requires any maintenance.
NOTE
As a preliminary check, ensure the EVXV coil
is snapped down fully, and the coil retention
tab is properly seated in one of the valve body
dimples.
FLOW
DIRECTION
1
4
3
2
1. Electronic Expansion
Valve
2. Coil Boot
3. Coil
4. Five Pin Connector
Figure 8-16. Electronic expansion valve
Diagnostics - Microprocessor or Wiring
a. Locate the wires, on the engine harness side of the
EVXV connector labeled EXVA, EXVB, EXVC,
EXVD and EXVE. These will correlate to the con-
nector pins labeled A, B, C, D and E. Refer to Table
8-3.
Table 8-3. EVXV Connections
Connector Pin Wire Color Winding
A ORANGE A
B RED B
C YELLOW
A
D BLACK
B
E GREY COM (+12V)
b. Place the SROS in the Start/Run position. DO NOT
ALLOW THE UNIT TO START. When the Mes-
sageCenter displays "SMV CLOSING", measure the
AC voltage between pins E & A and then between E
& B, E & C and E & D. A voltage should be read by
the digital voltmeter for each pair of wires. If the
reading is present on all of the wire pairs there is a
good signal coming from the microprocessor.
c. If the reading is not present on one or more of the
wire pairs, check the wiring between the micropro-
cessor and the SMV connector, or check the micro-
processor for proper model number Configuration.