Bard 11EER WA W18AB-A, Руководство пользователя для приложения

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Manual 7960-811
Page
3 of 13
Problem Probable Cause Solution
The green LED is not lit. Controller not
receiving 24VAC
signal. Check that the controller is getting 24VAC. Reference unit wiring
diagram for proper connections. If 24V is present, but the green
LED is not lit, replace the controller.
The red LED is flashing. One of the following is likely the fault:
1. Low superheat is
detected and the
controller is taking
steps to protect the
system by closing the
valve.
Stator is broken
or connected
incorrectly. Disconnect the stator from the valve and the control and measure
the resistance of the windings using an electrical tester. The
resistance of both windings should be around 40 ohms +/– 10%.
There are two sets of three wires that will have this resistance. If
the resistance falls outside these values, replace the stator.
Valve is stuck open. Check to see if valve can be moved by manually moving the
stepper motor using the EEV service tool (Bard Part # 2151-
021). See Figure 1. If valve still does not control, check the
temperature and pressure sensors as described below. If sensors
are good, replace the valve.
2. Suction temperature
sensor error.
Poor connection
of sensor or faulty
sensor. Refer to Table 2 on page 4 to check the resistance of the 10k
ohm NTC thermistor to determine if the sensor is faulty. Replace
sensor if no reading or out of range.
3. Suction pressure
transducer error.
Pressure transducer
wiring incorrect. Check continuity of all three wires from transducer plug to
controller plug. Replace wires if poor connection in any wire.
Check to ensure wires are correctly connected as follows:
Blue wire = pin 1 of controller plug to pin C on transducer plug
Red wire = pin 2 of controller plug to pin B on transducer plug
Black wire = pin 3 of controller plug to pin A on transducer plug
Transducer is faulty. Check that there is 5V between the red and black wires going
to the transducer. Then check the signal voltage on the blue
wire as described below in
Troubleshooting the Suction Pressure
Transducer . Replace transducer if out of range.
The red LED is on steady. The operating
parameters have
been damaged. The controller needs to be replaced.
Table 1
Electronic Expansion Valve Troubleshooting
Troubleshooting the Suction Pressure Transducer
0-250 psig
-5vdc Nominal .5 – 4.5vdc Actual
4v/250 psig = .016 volts per 1 psig
Example: 125 psig x .016 + .5 volts = 2.5 volts
Formula for Tech:
Measured Pressure x .016 = Expected Transducer
Signal Voltage (see Figure 2).
FIGURE 2
Voltage to Pressure: Suction Pressure Transducer