ABB R-MAG Instruction Manual page 11

7. Support the moving contact of the vacuum interrupter at the contact block (C) and loosen the
nut (F) taking care not to apply any torque to the end of the vacuum interrupter as damage
may result. (Figures 8).
8. With the stem nut loose (F), install the shoulder pin and washers through the triangular bell-
cranks) to the bolt stem (B) (E) and fasten with the new locknut provided.
9. Install the opposite end of the new bellcranks to the top of the pullrod (G) using the new "X"
type retaining washers provided and compress with pliers.
10. Torque the bolts and connections at (M) (N) per the torque specifications in section 9.0.8.
DO NOT TIGHTEN THE BOTTLE STEM NUT (F) ON THE VACUUM INTERRUPTER UNTIL
INSTRUCTED TO DO SO.
11. Ensure that the locknut (F) on the bolt stem (E) is loose while supporting the moving contact
to prevent any torque from being exerted on the internal bellows of the vacuum interrupter.
12. Remove the shoulder bolt (B) while applying pressure from the back of the contact block.
Allow the contact block to move slowly to the closed position. Caution: Finger pinch point.
13. Loosen the pullrod locknut (D).
14. Turn the pullrod until the center of the hole for the shoulder bolt (B) is 1.687" from the con-
tact block (C). (This step sets a reference point for the bell cranks.)
15. Spin the bolt stem (E) until the shoulder bolt (B) can be inserted, then remove the shoulder
bolt (B). (This step establishes a reference from VI contact to the bell cranks.)
16. Spin the bolt stem (E) 6 to 6.5 full turns (6.5 turns is preferred final travel, but 6 is acceptable
prior to contact conditioning) clockwise. (This step sets the contact travel.)
17. Pull from back of contact block (C) until shoulder bolt (B) can be inserted.
18. Install a new locknut and tighten all hardware. Note: When tightening the nut (F) on the stem
bolt (E), support the moving contact at the contact block (C) to prevent any torque from
being exerted on the internal bellows of the vacuum interrupter as damage may result.
19. Do not reuse washers.
20. Operate the breaker a minimum of 200 times to season the new contacts, and then readjust
the breaker (Step 9-19). Proceed to section 9.3 for final adjustment.
9.3 Contact Travel and Over-Travel Adjustment (See Figure 8) (Control power required)
1. Measure travel and over-travel by opening and closing the breaker. Confirm the breaker is
within the limits below (by voltage rating). While the breaker is in the closed position, minor
adjustments can be made by loosening the nut (D) and rotating the pullrod (A). Make sure all
hardware is tightened before operating the breaker and proceed to step 2 below by your
breaker voltage rating.
2. Over-travel gaps (L) (produced at top of each pullrod while the breaker is in the closed posi-
tion) are recommended to be set from 0.170" to 0.260" (when measuring breakers in opera-
tion, it is acceptable to be 0.125").
3. Travel limits (K) (difference in measurements between contact block in open and closed posi-
tion) are:
For 15.5 kV breakers = 0.413" to 0.492" (10.5 mm - 12.5 mm).
For 27 kV breakers = 0.591" to 0.630" (15.0 mm - 16.0 mm).
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