Diode Bridge Test; Transistor Leakage Test - PowerTec Regenerative Brushless DC Motor Control 1000AR Installation And Operation Instruction Manual

46
Page
D I O D E B R I D G E TE S T
Equipment : A Digital Multi-Meter (DMM)with a diode scale is preferred. You should have a RED lead in the
positive (+) input and a BLACK lead in the negative (-) input.
Preparation: Different meters give different readings on diode tests. KNOW YOUR METER !! Some meters read
backwards due to battery polarity. Test YOUR meter on a known good diode bridge before
performing tests so that you know how your meter will act.
Precautions: If the diode bridge is to be tested in circuit, make sure power has been off long enough for the
capacitor banks to completely discharge.
Procedure: The procedure is the same for in circuit or out of circuit testing. If a component tests bad in circuit, it
must be tested again after it is removed because of the possibility of alternate paths when the
component is in circuit.
1. Set the DMM on the diode scale.
2.
Place the RED (positive) lead on the "-" or "N" terminal of the diode bridge. Place the BLACK
(negative) lead on each of the AC terminals in turn. In each case you should read about 0.300
to 0.700 on a digital meter. If you see a short or an open circuit, disconnect the wires from the
diode bridge terminals and re-test.
3.
Repeat the above step with the BLACK lead on the "+" or "P" terminal of the diode bridge,
placing the RED lead on each of the AC terminals.
4.
Place the RED lead on the "+" or "P" terminal and the BLACK lead on the "-" or "N" terminal. It
should read an open circuit.
TR AN S I S TO R L E AK AG E TE S T
Equipment: A Digital Multi-Meter (DMM) is preferred. You should have a RED lead in the positive (+) input and a
BLACK lead in the negative (-) input.
Preparation: Set the meter on the 1000VDC scale. Be sure the leads are insulated for this voltage.
Refer to page 28 for the drive power schematic and semi-conductor diagrams.
Precautions: This test is an in-circuit test with power on. It should be performed by personnel who have been
trained to work around high voltage.
Procedure: Turn the drive power off and disconnect motor leads T1, T2, and T3.
Turn the power on and wait for the bus to charge (a green BUS LED). If the bus will not charge, turn
power off and go to TRANSISTOR MODULE STATIC TEST.
Measure the BUS voltage (POSITIVE BUS to NEGATIVE BUS) before beginning.
1. Place the Red lead of the meter on the POSITIVE BUS. Place the BLACK lead, in turn, on T1,
then T2, then T3. In each case, notice the voltage reading.
•
•
2. Repeat the above test with the BLACK lead on the NEGATIVE BUS and touching the RED
lead, in turn, to T1, T2, and T3. Check the transistor block connected to any T lead reading 0
VDC or BUS voltage.
•
•
1000AR
Model Installation and Operation Manual
If any voltage reading is 0 VDC, there may be a bad transistor. Turn off power, disconnect
the transistor module connected to the T lead with the bad reading, and perform the
TRANSISTOR MODULE STATIC TEST.
If any voltage reading is the same as the BUS VOLTAGE, it may indicate a problem in
the opposing transistor in that T lead leg or an unexpected alternate path in the circuit.
If any voltage reading is 0 VDC, there may be a bad transistor. Turn off power, disconnect
the transistor module connected to the T lead with the bad reading, and perform the
TRANSISTOR MODULE STATIC TEST.
If any voltage reading is the same as the BUS VOLTAGE, it may indicate a problem in
the opposing transistor in that T lead leg or an unexpected alternate path in the circuit.
6/4/2001 © copyright 1997 by Powertec