Danfoss VACON NXP FI9 Operating Manual page 91

Operating Guide | VACON® NXI Inverters FI9-FI14
The correct course of action is to ensure that the insulation layer of the capacitor is 'reformed' by the application of a limited current
using a DC supply. Current limiting ensures that the heat generated within the capacitor is kept at a sufficiently low level to prevent
any damage.
SHOCK HAZARD FROM CAPACITORS
The capacitors can be charged even when disconnected. Contact with this voltage can lead to death or serious injury.
If the AC drive or spare capacitors are intended to be stocked, discharge the capacitors before storage. Use a measuring
-
device to make sure that there is no voltage. If in doubt, contact your Danfoss Drives® representative.
Case 1: AC drive which has been non-operational or stocked for over 2 years.
1. Connect the DC supply to LI1 and L2 or the B+/B terminals (DC+ to B+, DC- to B-) of the DC-link or directly to the capacitor
terminals. In the NX AC drives with no B+/B- terminals (FR8-FR9/FI8-FI9), connect the DC supply between 2 input phases (L1 and
L2).
2. Set the current limit maximum to 800 mA.
3. Slowly increase the DC voltage to the nominal DC voltage level of the AC drive (1.35*U
4. Start to reform the capacitors.
The time of reforming depends on the time of storage. See
9
A
8
7
6
5
4
3
2
1
0
0 1
A Storage time (years)
C Reforming time
Illustration 32: Storage Time and Reforming Time
5. After the reforming operation is done, discharge the capacitors.
Danfoss A/S © 2019.11
2 3 4 5
D A N G E R
illustration 32.
C
6 7 8
B Reforming time (hours)
AC).
n
9
B
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