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Fault Tracing Thyristors
3ADW000488R0101 DCS880 Service manual e a
How to detect a faulty SDCS-BAB-F0x (H1 ... H4)
SDCS-BAB-F0x problems can be noticed differently:
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Fault messages related to the excitation.
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The field current is oscillating.
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A fuse F100 … F102 on the SDCS-PIN-H01 is blown (sizes H1 … H3) or a fuse F401 … F403 in the drive is
blown (size H4). This is an indication that a strong overcurrent has happened due an internal short circuit in
the bridge connected to the SDCS-BAB-F0x because of a defective thyristor or diode.
How to find a faulty SDCS-BAB-F0x
If a blown fuse on the SDCS-PIN-H01 or in the drive is suspected, the problem is caused most often by a faulty
SDCS-BAB-F0x. To make sure, that the SDCS-BAB-F0x is the reason and needs to be exchanged fault tracing
must be done in two different ways, depending on the size of the converter.
In general, make sure, that all safety instructions, given within this manual or within the
, related to the machine or the application itself, are obeyed.
Converters size H1 … H3 (20 ... 520 A)
The supply for the SDCS-BAB-F0x is passed via the SDCS-PIN-H01. Thus fuses F100 … F102 need to be
measured, before the SDCS-BAB-F0x is checked.
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The converter must be disconnected from the mains.
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Remove faulty thyristor modules
9. Remove the marked plugs at the SDCS-
PIN-H01.
10. Remove field connection plug X10 from the top of the DCS880.