ABB DCS800 Service Manual page 24

48 48
7. 7. Tighten the nuts of the mounting clamp by hand so that the clamp is in parallel Tighten the nuts of the mounting clamp by hand so that the clamp is in parallel
with the contact surface of the heat sinks. with the contact surface of the heat sinks.
Note Note : :
The indicating spring is a very sensitive instrument and must be handled with The indicating spring is a very sensitive instrument and must be handled with
care. care.
8. 8. Tighten each nut in turn, half a turn at a time with the help of a ring spanner 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 "correct torque" (see fig. Aluminum until the indicating spring clicks into position "correct torque" (see fig.
spring with welded indicating spring spring with welded indicating spring
further. further.
Note : : Note
The correct torque is indicated by means of the welded indicating spring. The correct torque is indicated by means of the welded indicating spring.
9. 9. Perform an OHM test to make sure the thyristor is ok. Perform an OHM test to make sure the thyristor is ok.
10. Reconnect the DC – busbars, branch fuses and all other dismantled parts. 10. Reconnect the DC – busbars, branch fuses and all other dismantled parts.
11. Perform an OHM test between U1, V1, W1 and C1, D1 to make sure the power 11. Perform an OHM test between U1, V1, W1 and C1, D1 to make sure the power
part is ok. part is ok.
left stack left stack
r r e e a a r r
V V 2 2 4 4
V V 1 1 3 3
V V 2 2 2 2
V V i i e e w w f f r r o o m m t t h h e e l l e e f f t t
Location of thyristors in frame Location of thyristors in frame D5 (4-Q bridge)
U U 1 1
f f r r o o n n t t
V V 1 1 1 1
V V 2 2 6 6
V V 1 1 5 5
D5 (4-Q bridge)
on page 47 on page 47). Do not tighten the screws any ). Do not tighten the screws any
V V 1 1 W W 1 1
F F r r o o n n t t v v i i e e w w
Aluminum
right stack right stack
f f r r o o n n t t r r e e a a r r
V V 1 1 4 4 V V 2 2 1 1
V V 2 2 3 3 V V 1 1 6 6
V V 1 1 2 2 V V 2 2 5 5
V V i i e e w w f f r r o o m m t t h h e e r r i i g g h h t t