Yaskawa Portable Control Display Unit - Manual (Page 54)

6 TEST MENU
48 Diagnostics
01/22/96
The drive has built-in diagnostic routines
that can be performed via the PCDU. The
Power Conversion Unit diagnostic routines
are able to test for three failure modes. The
first test that the Power Conversion Unit
performs is a test of the three line fuses.
Assuming the three line fuses are OK, the
Power Conversion Unit then performs a
test for shorted SCRs/doubler packs. If this
test indicates no shorted SCRs/doublers,
the Power Conversion Unit then tests for
open SCRs by passing current through the
forward bridge followed by the reverse
bridge. The results of each test are
displayed on the PCDU after each test is
completed.
WARNING
Current is circulated through
the armature circuit during the
Power Conversion Unit
Diagnostics function. The
Power Conversion Unit will
reduce the field current to zero
on motors with a shunt field in
order to minimize motor
rotation. However, a
PERMANENT MAGNET motor
must have its shaft locked
mechanically prior to running
the Power Conversion Unit
Diagnostics. If the Power
Conversion Unit detects
significant motor voltage during
the test, the Power Conversion
Unit Diagnostics function will
abort.
Diagnostics
(Function # 998)