Danfoss VLT FC 100 Service Manual page 73

Test Procedures Service Manual
Perform all tests with a meter capable of testing diodes.
Use a digital volt/ohmmeter (VOM) set on the diode scale
or an analog ohmmeter set on Rx100 scale. Before making
any checks, disconnect all input, motor and brake resistor
connections.
Figure 6.3 is provided as a reference for finding the
appropriate connectors described in the test procedures in
this section. Some connectors are optional and not on all
adjustable frequency drive configurations.
NOTICE!
6 6
For best troubleshooting results, perform the static test
procedures described in this section in the order
presented.
Diode Drop
A diode drop reading varies depending on the model of
ohmmeter. Whatever the ohmmeter displays as a typical
forward bias diode is defined as a diode drop in these
procedures. With a typical DVM, the voltage drop across
most components is around 0.300 to 0.500. The opposite
reading is referred to as infinity and most display the value
OL for overload.
MG94A222 Danfoss A/S © Rev. 2014-02-10 All rights reserved. 71