Hpa - Operating Gear Adjustments - ABB HPA 12kV Instruction For Installation, Service And Maintenance

1.4.8 Changing of breaker pole
1. Loosen the operating device according to section 1.4.7
2. Loosen the 2 screws of the operating arms. (The pole in the middle has no
screws). Remove the links and arms.
3. Remove the density gauge (special key) or loosen the cover for gas refilling.
4. Put on the long cover which is mounted on the new pole.
Note: Do not put on the short cover, without the density gauge, because the
back pressure valve will open allowing gas to escape.
5. Loosen the pole with key 32 and 55. Loosen the M12 screws.
6. Mount the long cover on the new pole.
7. Fit the new pole.
8. Mount the long cover on the old pole and mount the density gauge and short
cover. (Check that the O-ring are good). Fasten the nuts with special tool.
9. Replace the short cover.
2.4.9 HPA-Operating gear adjustments (ref. Fig. 5, 7A, 7B)
For a preliminary adjustment, check the operating gear separate and without
springs and dash pot.
Locate the dock point screw (B) on top shaft are in minimum position
(unlocked). This is to ensure that the trip free mechanism operates safely when
the spring is charged and thus preventing "dummy stroke".
1. Adjustment of knee joint (blue gauge) adjust gap (3) (from centre of upper pin
in push rod to a line from centre of upper shaft to the lower pin in push rod)
3.5 - 4.5 with the help of dog-point screw (A). Lock the screw after adjustment.
2. Adjustment of lower shaft - closed position. The arm (H) must hit the stop (C),
but not enough to cause blocking of push rod when forced over knee position.
Lower trip free mech. must remain in locked position. Secure the lock nut
after adjustment.
3. Adjustment of lower shaft.
4. Lower dash pot. Mount the dash pot (F). Check the dash pot piston has an
over travel of 0.5 to 2 mm when lower shaft is in final "trip" position. If
necessary adjust with washers. Secure the loci nut.
5. Upper dash pot and springs. Mount upper dash pot (G) opening spring,
closing spring and return spring. Over travel in dash pot should be 0.5 to 2
mm if necessary adjust with washers.
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