9 Special Test Equipment
9.1 Test Equipment
Test tools have been developed to aid in troubleshooting these products. It is highly recommended
for repair and servicing this equipment that these tools be available to the technician. Without
them, some troubleshooting procedures described in this manual cannot be carried out. Although
some test points can be found inside the adjustable frequency drive to probe for similar signals,
the test tools provide a safe and sure location for making necessary measurements. Test equip-
ment described in this section is available from Danfoss.
Using the test cable allows powering the adjustable frequency drive without having
to charge DC bus capacitors. Main input power is required and all devices and power
supplies connected to line power are energized at rated voltage. Use extreme cau-
tion when conducting tests on a powered adjustable frequency drive. Contact with
powered components could result in electrical shock and personal injury.
9.1.1 Test Cables and SCR Shorting Plug Kit p/n 176F8439
This tool provides the ability to power up the
Switch Mode Power Supplies (SMPS) and ac-
tivate all the control functions of the adjusta-
ble frequency drive without having the DC bus
capacitors charged. It provides protection for
troubleshooting gate drive signals and other
important control signals within the adjustable
frequency drive.
The test kit includes the shorting plug and
connector cables. The cable is connected be-
tween the soft charge card and the power
card. The SCR shorting plug shorts the gates
of the SCRs to ensure they do not fire and add
a charge to the DC bus.
130BX64.10
Figure 9.1: SCR Shorting Plug
WHITE
BLACK
PIN 1
PIN 2
Figure 9.2: Two-pin D frame test cable
PIN 1
PIN 1
PIN 2
PIN 3
PIN 2
Figure 9.3: Three-pin E frame test cable
High Power Service Manual for VLT
®
FC Series
Adjustable Frequency Drives
9 Special Test Equipment
MG.90.L1.22 - VLT
®
is a registered Danfoss trademark
9-1
9
Summary of Contents for VLT HVAC FC 100
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