Danfoss VLT HVAC FC 100, Service Manual, Page: 95 / 220

6.2 Static Test Procedures
All tests should be made 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 Power Card PCA Connector Identification is provided as a reference for finding the
appropriate connectors described in the test procedures in this section. Some connectors are op-
tional and not on all adjustable frequency drive configurations.
NOTE!
For best troubleshooting results, it is recommended that static test procedures de-
scribed in this section be performed in the order presented.
Diode drop
A diode drop reading will vary 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 will be around .300 to .500. The opposite
reading is referred to as infinity and most DMVs will display the value OL for overload.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
130BX172.10
Figure 6.5: Power Card, and Mounting Plate
380–480/500V: Yellow tape on the main SMPS transformer in the upper right corner.
525–690V: White tape on the main SMPS transformer in the upper right corner.
1 Power card PCA3 9 MK106
2 Mounting plate 10 MK100
3 MK110 11 MK109
4 MK102 12 FK102
5 MK104 13 MK112 terminals 4, 5, 6
6 MK105 14 MK112 terminals 1, 2, 3
7 MK107 15 Scaling card
8 FK103 16 Scaling card standoff
6 Test Procedures
High Power Service Manual for VLT
®
FC Series
Adjustable Frequency Drives
6-4
MG.90.L1.22 - VLT ® is a registered Danfoss trademark
6