PowerTec 2000C Instruction Manual page 65

ELECTRICAL TESTS
WITH POWER
APPLIED BUT NOT
RUNNING MOTOR
Page 8-2
1. Connect a voltmeter to the bus capacitors with the scale set to
1000VDC.
- Turn on the breaker to the equipment and observe the voltage
indicated on the meter. It will start at zero volts and climb rapidly to near
640VDC (320 for 230VAC units) in approximately 15 seconds. At
the point that the bus reaches 560VDC a contactor in the drive will turn on
and bypass the charging resistor and at that point the bus will charge instantly
to the full 640VDC. If the bus voltage does not come up quickly and within
30 seconds maximum, there may be a problem preventing the charge up. This
is an abnormal condition and action should be taken to determine where the
problem lies before continuing. Call the factory for additional information.
2. During the power-up process the following LEDs will be on:
Power On
Bus
Zero Speed
- At the moment the contactor pulls in, the bus LED will turn from red
to green.
Do not depress the run pushbutton yet. There are more checks to make!!
3. This step will check the proper operation of the three commutation
hall effect channels and the two speed feedback channels coming back to the
current regulator board on TB1.You will need a voltmeter or an oscilloscope
for this check. Connect either the meter or the scope common to TB1-1
(Drive Common). A more convenient place to connect an alligator-type clip
to common is to the heatsink tab of the positive regulator on the speed board.
There are two regulators on the board under the ribbon cable connecting the
two boards. This will be the one on the right side. Connect the positive lead
of the meter or the probe of the scope to TB1-2 and rotate the motor shaft by
hand. The voltage at this point should switch from a few tenths of a volt to
8.5 volts in a square wave as the motor rotates. The switching will occur four
times per revolution for a 250 Series or smaller motor and eight times per
revolution for a 280 Series or larger motor. Repeat the above measurements
for terminals TB1-3 and TB1-4. Each of the three terminals will have a
similar output, switched as the motor rotates in either direction. This checks
all three of the commutation channels. Move the positive meter lead or scope
probe to TB1-5 and turn the motor. Many more pulses will be available. The
voltage levels should be the same as before but will switch from low to high
30 times per revolution for a small motor up through 250 Series frames and
60 times per revolution for big motors of the 280 and 320 Series. Move the
lead to TB1-6 and you should see the same signals being switched.
4. Turn the current limit potentiometer on the drive to zero (full
counter-clockwise). Set the speed reference on the drive to approximately
10%. This can be determined by measuring the voltage from TB2-12 to TB2-
10 and setting it at 1 volt. Energize the drive with the start pushbutton and the
run LED and the current limit LED should come on on the speed regulator
board. The motor will not actually run because the current limit is set at zero.
The enable LED on the current regulator board should come on. Leave the
current limit pot set to zero (full counter-clockwise.)
Color Green
Red
Out
Model 2000C/3000C Instruction Manual