Balance/High Frequency Card - Danfoss VLT FC Series Service Manual

E1h–E4h Drive Disassembly a...

13.2.17 Balance/High Frequency Card

To remove or reinstall the balance/high frequency card, use the following steps. Refer to Illustration 13.16.
NOTICE
PARTS REUSE
In T7 units (525–690 V AC), retain the screw (T25) that is removed from the balance/high frequency card. Using a longer
screw during reassembly can damage the insulator sheet behind the card.
Disassembly
1. Remove the input plate. Refer to
chapter 13.2.9 Input Plate with Busbars or
chapter 13.2.10 Split Input Plate with Options.
2. Remove the gate drive card mounting plate. Refer
to chapter 13.2.13 Gate Drive Card Mounting Plate.
3. Remove the left IGBT output busbar by removing:
3a 1 nut (13 mm) from the upper end of
the left current sensor busbar.
3b 2 nuts (13 mm) from the upper end of
the left IGBT output busbar.
3c 1 screw (T25) from the middle of the
left IGBT output busbar. This screw is
not present in E2h/E4h drives.
4. Remove the center IGBT output busbar by
removing:
4a 1 nut (13 mm) from the upper end of
the center current sensor busbar.
4b 2 nuts (13 mm) from the upper end of
the center IGBT output busbar.
4c 1 screw (T25) from the middle of the
center IGBT output busbar. This screw is
not present in E2h/E4h drives.
5. Unplug the cable from connector MK100 on the
balance/high frequency card. This connector and
cable are present only in T7 units (525–690 V AC).
6. Release the cable from the cable retaining clips.
7. Remove 4 nuts (8 mm) from the card, including
those attaching the white DC(+) wire and black
DC(-) wire. In T7 units (580–690 V AC), also
remove 1 screw (T25), and retain the screw. Using
a longer screw can damage the insulator sheet
behind the card.
8. Lift the balance/high frequency card and the
insulator sheet from the drive.
MG94A502
Service Guide
Reassembly
Tighten fasteners according to chapter 14.1 Fastener Torque
Ratings.
1.
2.
3.
4.
5.
6.
7.
8.
Danfoss A/S © 02/2019 All rights reserved.
Position the insulator sheet on the capacitor
plate.
Place the balance/high frequency card over the
insulator sheet.
Fasten 4 nuts (8 mm) in the balance/high
frequency card, attaching the white wire at the
DC(+) marking and the black wire at the DC(-)
marking. In T7 units (580–690 V AC), also replace
1 screw (T25) that was retained during
disassembly. A longer screw can damage the
insulator sheet behind the card.
Attach the cable to the MK100 connector. This
connector and cable are present only in T7 units
(525–690 V AC).
Replace the center IGBT output busbar by
securing:
5a 2 nuts (13 mm) in the upper end of the
center IGBT output busbar.
5b 1 screw (T25) in the middle of the IGBT
output busbar. This screw is not present
in E2h/E4h drives.
5c 1 nut (13 mm) in the upper end of the
center current sensor busbar.
Replace the left IGBT output busbar by securing:
6a 1 nut (13 mm) in the upper end of the
left current sensor busbar.
6b 2 nuts (13 mm) in the upper end of the
left IGBT output busbar.
6c 1 screw (T25) in the middle of the left
IGBT output busbar. This screw is not
present in E2h/E4h drives.
Reinstall the gate drive card mounting plate.
Refer to chapter 13.2.13 Gate Drive Card Mounting
Plate.
Reinstall the input plate. Refer to
chapter 13.2.9 Input Plate with Busbars or
chapter 13.2.10 Split Input Plate with Options.
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