3. Reconnect the motor to the frequency converter.
4. Connect mains to the frequency converter, and
start the frequency converter.
5. Monitor current on the 3 output phases at the
motor terminals U, V, and W, using the clamp-on
ammeter. An analog device is preferred. To
achieve an accurate reading, run the frequency
converter above 40 Hz as this is normally the
frequency limitation of such meters.
The output current must be balanced from phase-to-phase,
and no phase must be more than 2–3% dierent from
another. If these tests are successful, the frequency
converter is operating normally.
6. If the imbalance is greater than described
previously, disconnect the motor cables and
repeat the voltage balance test.
7. Stop the motor and disconnect mains from the
frequency converter.
Since the current follows the voltage, it is necessary to
dierentiate between a load problem and a frequency
converter problem. When a voltage imbalance in the
output is detected with the motor disconnected, the
inverter is faulty. Exchange the frequency converter.
6.4.7 Input Terminal Signal Tests
The presence of signals on either the digital or analog
input terminals of the frequency converter can be veried
on the frequency converter display. Digital or analog input
status can be selected or read in parameters 16-60 to
16-64.
Digital inputs
With digital inputs shown, control terminals 18, 19, 27, and
29 are shown left to right, with a 1 indicating the presence
of a signal.
If the desired signal is not present in the display, the
problem is either in the external control wiring to the
frequency converter or a faulty control card. To determine
the fault location, use a voltmeter to test for voltage at the
control terminals.
Verify that the control voltage power supply is correct
as follows:
1. Use a voltmeter for measuring voltage at control
card terminal 12 and 13 with respect to terminal
20. The meter should read 21-27 V DC.
If the 24 V supply voltage is not present, test the control
card in chapter 6.2.1 Introduction.
If 24 V is present, proceed with checking the individual
inputs as follows:
2. Connect the (-) negative meter lead to reference
terminal 20.
3. Connect the (+) positive meter lead to the
terminals in sequence.
The presence of a signal at the desired terminal must
correspond to the digital input display readout. A reading
of 24 V DC indicates the presence of a signal. A reading of
0 V DC indicates that no signal is present.
Analog inputs
The value of signals on analog input terminals 53 and 54
can also be shown. The voltage or current in mA,
depending on the switch setting, is shown in line 2 of the
display.
If the desired signal is not present in the display, the
problem is either in the external control wiring to the
frequency converter, or a faulty control card. To determine
the fault location, use a voltmeter to test for a signal at the
control terminals.
Verify that the reference voltage power supply is correct
as follows.
1. Use a voltmeter for measuring the voltage at
control card terminal 50 with respect to terminal
55. The meter must read between 9.2 and 11.2 V
DC.
If the 10 V supply voltage is not present, conduct basic
control card voltage test, see chapter 6.4.3 Basic Control
Card Voltage Test.
If 10 V is present, proceed with checking the individual
inputs as follows.
2. Connect the (-) negative meter lead to reference
terminal 55.
3. Connect the (+) positive meter lead to desired
terminal 53 or 54.
For analog input terminals 53 and 54, a DC voltage
between 0 and +10 V DC must be read to match the
analog signal sent to the frequency converter. Or a reading
of 0.9 V DC to 4.8 V DC corresponds to a 4–20 mA signal.
NOTICE
A (-) minus sign preceding any reading above indicates a
reversed polarity. In this case, reverse the wiring to the
analog terminals.
Test Procedures TR150 and TR170 Service Manual
BAS-SVM04B-EN 02/2017 All rights reserved. 55
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