Section 8 Special Test Equipment; Test Equipment; Test Cable And Scr Shorting Plug (P/N 176F8439); Test Cable And Scr Shorting Plug - Danfoss VLT Series Service Manual

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 drive to probe for similar signals, the
test tools provide a safe and sure point for making necessary
measurements. Test equipment described in this section is
available from Danfoss.
WARNING
!
Use of test cable allows powering the drive
without charging DC bus capacitors. Main input
power is required and all line powered devices
and power supplies are energized at rated
voltage. Use extreme caution when conducting
tests on a powered drive. Contact with powered
components could result in electrical shock and
personal injury.
Test Cable and SCR Shorting Plug (p/n
176F8439)
Cable with connectors
Figure 8-1. Test Cable and SCR Shorting Plug
This tool provides the ability to power up the Switch Mode
Power Supplies (SMPS) and activate all the control functions
of the drive without having the DC bus charged. It provides
protection for troubleshooting gate drive signals and other
important control signals within the drive than having the
DC bus disabled.
The cable is connected between 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.
SECTION 8
SPECIAL TEST EQUIPMENT
Test cables provided after September, 2005, are usable on all
drives described in this manual. Test cables prior to that date
are shorter and apply only for D-frame size units.
To install the cable, first ensure the drive is powered down
and the DC bus is fully discharged.
When reapplying main input power to the drive, the soft charge
rectifier provides DC power to the power card. Testing with
the use of the gate signal board and the signal test board can
SCR shorting plug
now be carried out without the presence of DC bus voltage.
1. For D-frame size units, follow procedure in Section
6 for soft charge card removal and disengage soft
charge card far enough to disconnect cable
plugged into MK3.
2. For all frame sizes, disconnect cable from MK3
connector on soft charge card and connect one
end of test cable into MK3.
3. For D-frame size units, reinstall soft charge card.
4. For all frame sizes, disconnect connectors MK100
and MK105 on power card.
5. For all frame sizes, connect free end of test cable
into MK105.
6. For all frame sizes, connect SCR gate shorting plug
(included with test cable 176F8437) into cable that
was removed from MK100.
VLT is a registered Danfoss trademark
8-1