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Chapter 6 - Exchange of Thyristors for Size A6
VI A
6 - 2
DCS 500 / DCS 600 Service Manual
BCT thyristors
In some converter module size A6 so called BCT’s (
B
idirectional-
C
ontrolled-
T
hyristors) are used. BCT’s are a pair of anti parallel thy-
ristors in one disk type housing. They can easily identified by the
second pair of gate leads. The second gate is marked with
Gate B
on the thyristor.
Faston 4.8 x 0.5
Gate A
Faston 6.3 x 0.8
Gate B
Figure 6-1
Gates of BCT
Note
: The faston connectors of the gates are of different size.
Gate B should always be in front of the clamped heat sinks due to
cooling reasons.
Figure 6-2
Location of BCT’s gate B when built in
BCT.dsf
Gate A
Gate B
3ADW000093R0701_DCS500B/DCS600_Service manual_e_g