8.5.11 IGBT Gate Drive Signals Test
NOTICE
DRIVE TYPE
This test is applicable to only D-sized drives. E1h–E4h
drives do not have test connectors on the gate drive
card.
This procedure tests the gate drive signals at the output of
the gate drive card just before they are delivered to the
IGBTs. A simple test to check for the presence of the gate
signals can be performed with a voltmeter. To check the
waveforms more precisely, however, an oscilloscope is
required.
NOTICE
POTENTIAL PIN DAMAGE
Disable the DC bus when performing this test with split
bus power supply. Failure to do so can result in damage
to the drive if the probe is inadvertently connected to
the wrong pins.
Before beginning the tests, ensure that power is removed
from the unit and that the DC bus capacitors have fully
discharged.
Install the split bus power supply.
1. Remove the AC busbars or RFI lter (option).
2. Connect the split bus power supply. Refer to
chapter 9.1.1 Overview.
In D-sized drives, there is a 3-pin test connector on the
gate drive card near each gate signal lead. Refer to
Illustration 8.8. These leads are labeled:
•
MK500
•
MK502
•
MK600
•
MK602
•
MK700
•
MK702
•
MK200 (if equipped with a brake option)
See Illustration 8.8.
Refer to the 3 pins as 1, 2, and 3, reading bottom to top.
Pins 1 and 2 of each connector are in parallel with the
gate drive signal sent to the IGBTs. Pin 1 is the signal and
pin 2 is common.
1. Turn on the split bus power supply (only 650 V).
2. In stop mode, measure pins 1 and 2 of each test
connector. A correct reading is approximately -9 V
DC, which indicates that all IGBTs have been
turned oîš‚.
3. Apply the run command to the drive and 30 Hz
reference.
4. If using a voltmeter, measure pins 1 and 2 of
each connector. Waveform to IGBTs is a square
wave that goes positive to 14 V DC and negative
to -9 V DC. Average voltage read by the
voltmeter is 2.2–2.5 V DC.
When using an oscilloscope, the readings in Illustration 8.16
are correct.
Test Procedures
VLT
®
FC Series, D1h–D8h, Da2/Db2/Da4/Db4, E1h–E4h, J8/J9
112 Danfoss A/S © 02/2019 All rights reserved. MG94A502
88
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