ABB DCS 500 Series Service Manual page 35

DCS 500 / DCS 600 Service Manual
7. Tighten the nuts of the mounting clamp by hand so that the
clamp is in parallel with the contact surface of the heat sinks.
Note: The indicating spring is a very sensitive instrument and
must be handled with care.
8. Tighten each nut in turn, half a turn at a time with the help of a
ring spanner until the indicating spring clicks into position "cor-
rect torque" (see figure 5-3 ). Do not tighten the screws any fur-
ther.
Note: The correct torque is indicated by means of the welded
indicating spring.
9. Perform an OHM test to make sure the thyristor is ok.
10. Reconnect the DC – busbars, branch fuses and all other dis-
mantled parts.
11. Perform an OHM test between U1, V1, W1 and C1, D1 to make
sure the power part is ok.
left stack
rear front
V24 V11
V13 V26
V22 V15
View from the left
Figure 5-4 Location of thyristors in frame A5 (4-Q bridge)
3ADW000093R0601_DCS500B/DCS600_Service Manual_e_f
Chapter 5 - Exchange of Thyristors for Size A5
U1 V1
Front view
W1
right stack
front rear
V14 V21
V23 V16
V12 V25
View from the right
VI A 5 - 5