WESTINGHOUSE DV-P (01) PDF Document

Receiving and Handling:

The WESTINGHOUSE DV-P breakers are shipped fully assembled and ready for service. However, before placing the breaker in service, refer to the Maintenance Guide.

Handle all parts carefully, especially the vacuum interrupters, which are encased in porcelain and subject to breakage. Be particularly careful near the interrupter bellows; they must never be twisted as this decreases their useful life.

Upon receipt, immediately inspect the breaker for any signs of shipping damage. If damage is found, file a claim with the transportation company and notify the nearest Westinghouse Electric Corporation Sales Office.

Storing:

During storage, keep all parts in a clean, dry place. The storage area should be warm enough and have sufficient clean air circulation to prevent moisture condensation.

The WESTINGHOUSE DV-P circuit breaker can be lifted with its main barrier assembly in place. To lift the breaker:

1. Attach crane hooks in the notches provided on the breaker chassis.

2. Ensure the crane hooks are positioned inside the barrier panels to prevent damage to the barrier assembly.

Note: The breaker must be completely removed from the cell before you can tilt or remove the barrier. This is a safety feature.

To Tilt the Barrier Back:

1. With the breaker removed from the cell, remove the two screws located at the bottom edge of the front steel panel.

2. The barrier assembly will now pivot on the lower rear brackets. You can tilt it back until the upper edge of the front panel rests on the floor behind the breaker.

3. To return the barrier to its original position, reverse the steps. Ensure the tab on the lower edge of the front panel engages the turned-up edge on the front of the breaker. Re-insert and securely tighten the two screws.

To Remove the Barrier:

1. First, remove the two screws from the bottom of the front panel.

2. Next, remove the four screws that hold the barrier to the lower rear brackets.

3. Once these six screws are removed, the barrier assembly can be lifted off the breaker.

To Install the Barrier:

1. Place the barrier assembly on the breaker with the steel panel at the front and the insulation sheets between the poles.

2. Ensure the tab at the center bottom edge of the front steel panel engages the turned-up edge on the front of the breaker chassis.

3. Fasten the front steel panel to the breaker chassis with its screws and tighten them securely.

4. Place the four bolts with spacers in the rear brackets and secure them.

CAUTION: Use the handle on the front steel panel of the barrier assembly to push or pull the breaker. The six screws fastening the barrier must be securely tightened before attempting to move the breaker with this handle. Failure to do so may result in equipment damage or personal injury.

For general movement where corners must be turned, use the handling dolly:

1. Place the vertical pin of the dolly into the hole in the handling bracket at the bottom center of the front chassis panel. Do this by tilting the dolly handle sharply toward the breaker.

2. Turn the dolly handle downward until the front wheels of the breaker lift off the floor.

3. The breaker can now be steered by the horizontal movement of the dolly handle.

1. Examine the disconnecting finger clusters for any signs of damage. Ensure they are properly positioned and that the retaining bolts are all in place. Clean off any dirt or debris; grease is not necessary.

2. Make sure the cell is clean and clear of anything that might interfere with the breaker’s travel. The levering screw in the cell should be clean and free from dirt or grit.

3. Align the guide channel on the right-hand side of the breaker (near the floor) with the guide rail on the right-hand side of the cell floor.

4. Push the breaker into the cell until the rail latch at the front of the guide channel catches in the notch in the guide rail. This will stop further movement of the breaker toward the rear of the cell, securing it in the TEST POSITION.

CAUTION: The pole unit parts are live at full circuit voltage when the breaker is in the fully energized position. Before moving the breaker into this position, make sure the main barrier assembly has been properly fastened in place. Failure to do this may cause serious damage or injury.

A mechanical interlock prevents levering the breaker if it is in the closed position.

1. Press down on the rail latch on the breaker.

2. Push the breaker toward the rear of the cell as far as it will go (about 1/4 to 3/8 inch) until it is stopped. This brings the levering nut on the breaker up to the screw in the cell.

3. Engage the crank on the levering shaft. Push the breaker moderately toward the rear of the cell and turn the crank clockwise. The breaker should move slowly toward the rear of the cell.

4. Continue cranking until the crank turns freely and the breaker stops moving. When the breaker is fully engaged, the front steel barrier should be about 1/4 inch or less from the cell frame angles.

CAUTION: This is a valuable piece of equipment. Handle it carefully to avoid damage from rough handling.

1. Engage the crank on the levering device shaft and turn it counterclockwise until the crank rotates freely.

2. Pull the breaker toward the front of the cell until the rail latch engages the slot in the rail. The breaker is now secured in the test position.

1. From the test position, press down on the rail latch to free the breaker from the rail.

2. Pull the breaker out of the cell.

NOTE: As the breaker is withdrawn from the test position, the stored energy mechanism may open or trip free. This is a safety measure to discharge the closing and opening springs.

To Engage Secondary Contacts:

1. Lift the “T” handle on the left-hand side at the front of the chassis to a horizontal position. Lift further to disengage the notch in the rod from the top edge of the panel and push it toward the rear of the breaker. The small horizontal pin in the “T” handle should engage the two slots in the levering handle above it.

2. Push down on the curved end of the levering handle as far as it will go. This provides leverage for the final full makeup of the contacts.

To Disengage Secondary Contacts:

1. Lift up on the levering handle for the initial break of contacts.

2. Pull the “T” handle out as far as it will go and let it drop to the vertical position.

To Charge the Closing Spring by Hand:

1. Place the end of the combination spring charge/maintenance handle into the slot in the manual ratchet lever. This lever projects through a slot in the front chassis panel.

2. Charge the spring with several downward movements of the handle until the handle suddenly turns freely and a “click” is heard. Do not attempt to continue ratcheting, as this will cause damage.

To Spring Close the Breaker without Electric Power:

1. Charge the closing spring as described above.

2. Place a finger under the plunger marked “Lift to Close” and push up. This releases the closing latch and the breaker closes.

To Open the Breaker by Hand:

1. Place a finger under the plunger marked “Lift to Trip” and push up.

NOTE: This feature is for maintenance and observation only and is disabled when the breaker is beyond the test position in the cell. The breaker should be closed with the maintenance handle ONLY WHEN THE CLOSING SPRING IS DISCHARGED.

CAUTION: Always remove the maintenance closing handle before opening the breaker with the tripping trigger. The handle is not trip-free in this mode and will move upward fast if left on the shaft when the breaker is tripped.

To Close with the Maintenance Handle:

1. Ensure the closing spring is discharged.

2. The flat end of the main shaft projects through the right-hand side of the breaker chassis.

3. Place the slot in the closing handle over the flats on the main shaft and push downward until the breaker latches close.

4. Remove the handle from the shaft.

To Open the Breaker Contacts Slowly for Observation:

1. With the breaker in the closed position, place the maintenance closing handle on the main shaft.

2. Press down with a force about equal to that required to close the breaker.

3. Hold this position and lift the trip plunger.

4. Let up slowly on the handle to make the desired observations.

The main shaft extends through the right-hand side of the breaker chassis. A spring charge/maintenance handle has a rectangular hole that fits on the end of the shaft for hand closing and opening the breaker. This operation is solely for adjusting the wear gap, contact stroke, or other working parts when slow motion is required.

Important Safety Precautions:

• The breaker can be closed with the maintenance handle only when the closing spring is discharged. Attempting to hand close the breaker with a charged spring may damage the mechanism.

• Do not ever attempt to close the breaker by hand against a live circuit. Proper closing requires more speed and power than can be supplied by hand.

• When using the maintenance closing handle, the control circuit should be entirely disconnected to prevent accidental electrical operation.

• If the breaker is closed and latched with the maintenance closing handle, be sure to remove it from the shaft before tripping the breaker.

The integrity of the vacuum can be checked by performing a Hi-Pot test.

1. Open the breaker.

2. Hi-Pot the open contacts of each phase with 36 KV A.C. for one minute.

3. If the interrupter does not flash over during the one-minute interval, it should function properly. This voltage is higher than standard field testing values for 15 KV switchgear but is necessary to verify the vacuum.

Safety Note: Applying high voltage across an open vacuum gap can produce X-ray emissions. While the level is extremely small and below permitted standards under normal conditions, it is advisable that all operating personnel stand behind the steel front barrier and remain further from the breaker than necessary for electrical safety during the Hi-Pot test.

After the test, the vapor shield inside the vacuum interrupter may acquire an electrostatic charge. This charge should be bled off immediately by grounding the metal ring that circles the center of the ceramic envelope.

The contact stroke and wear gaps are factory set at .25″ and should be checked every 2000 operations.

1. Move the breaker outside the cell.

2. Tilt the barriers back to expose the interrupters and mechanism.

3. Close the breaker contacts.

4. Check the gap with a .25″ thick rod. As contacts erode, this gap will diminish.

Important: WHEN THE WEAR GAP IS DOWN TO .04″ THE VACUUM BOTTLE MUST BE REPLACED and the wear gaps reset to .25″ again. Never allow the gap to disappear, as there will be no force holding the contacts closed. The wear gaps should not be reset after the breaker has been put in service, as this would invalidate the record of contact life. When an interrupter is replaced, the gaps are set to .25″, and the contact travel will automatically be .65″ to .69″.

Follow this procedure to replace a vacuum bottle and set the wear gaps:

Disassembly:

a. Take the breaker out of the cell.

b. Remove “X” washers from the operating rod pin at the top of the operating rods.

c. Using the maintenance handle, slowly close the breaker until the wear gap starts to appear. Just before the gap appears, the pin should be easily removable from the operating rod. Remove it.

d. Remove the 6″ long bolt clamping the top conductors to the upper stud.

e. Remove the two nuts holding the top conductors to the insulators. Remove the upper nut on the front insulator strut.

f. Lift off the top conductor.

g. Remove the mounting nuts holding the bottle to the lower mounting assembly. DO NOT PULL UP ON THE BOTTLE. It must be pushed up by its stem. Use a 4″ long steel tube (1.250″ OD, 7/8″ to 1″ ID) placed over the stud and locknut on the bottom stem. Push up on the tube to free the bottle. DO NOT PULL UP (OR TURN) THE BOTTLE.

Assembly and Adjustment:

h. Mount the new bottle by placing its stud and locknut into the tube. Align the operating rod pin hole and mounting studs. Press or lightly tap the bottle into place. DO NOT TURN THE BOTTLE ONCE THE ROLLERS MAKE CONTACT WITH THE BOTTLE STEM. Tap only on the upper stem.

i. Lubricate rollers lightly with specified compound 53701RK.

j. Slip top conductors on the upper stem of the bottle.

k. Align the finger cluster end of the top conductor assembly by measuring from adjacent stud centerlines. The distance should be 10.00″ ±.03 vertically and horizontally.

l. Tighten the nuts holding the top conductor to the insulators while maintaining stud alignment. Then, tighten the 6″ long clamping bolt to 60 ft. lbs.

Set Wear Gaps:

a. Loosen the bottom nut on the bottom of the operating rod. After it is loose, turn the nut down an additional 1/2 inch.

b. Attach the operating rod to the vacuum interrupter with the pin and new “X” washers.

c. Slowly close the breaker with the maintenance handle while watching the wear gap. If the gap gets larger than .38″ before latching, reopen the breaker and turn the upper nut on the operating rod upward to shorten it. If no gap appears, the rod is too short; turn the upper nut down. Slowly close the breaker until a gap of .31″ appears when closed. Then tighten the lower nut on the bottom of the operating rod. This results in a wear gap of about .25″. The lower nut should be very tight; the upper nut is not tightened.

There should be .02 to .03 inch clearance between the tripping trigger and the tripping latch roller when the breaker is open and the spring is charged. If there is no clearance, the tripping latch cannot drop into place, and the breaker will not close at all.

To adjust this clearance:

1. Open the breaker and charge the closing spring.

2. Locate the trip cam adjusting screw on the front chassis panel under the handling dolly bracket.

3. Loosen the locking nut on the adjusting screw.

4. Turn the screw in until it stops against the tripping cam.

5. Back the screw out until there is a .03 gap between the opening trigger and the tripping latch roller.

6. Tighten the locking nut.

The latch check switch makes contact when the tripping trigger is in the fully reset position, ready for the breaker to close. It is factory set and should not need adjustment unless tampered with.

The switch is properly adjusted if it makes contact when the tripping trigger is 1/8 to 3/16 inch from its completely reset position, as measured at the center of the trip plunger stem.

If adjustment is needed, it can be done by slightly bending the tough steel operating arm of the switch.

Proper lubrication ensures reliable performance. All parts requiring lubrication are treated with “molly” (molybdenum polysulphide) Westinghouse M. No. 53701GC during assembly.

At the 2000 Operation Maintenance Period:

Lubricate the following points sparingly with light machine oil or auto crankcase oil:

• Front and rear tripping latch rollers and pivot pin.

• Tripping trigger pivot pin.

• Spring release latch roller and pivot pin.

• Closing trigger and pivot pin.

• Tripping cam pivot pin and restraining link pin.

Long-Term Lubrication:

Roller bearings on the pole unit shaft, crankshaft, connecting rod, and closing cam follower are packed with a top-grade slow-oxidizing grease (Westinghouse M. No. 55213AG or “Molycote”) at the factory, which should last for many years. These bearings should not be disturbed unless there is definite evidence of sluggishness, dirt, or if parts are dismantled.

If cleaning is necessary, thoroughly clean the bearings and parts of old grease using a good grease solvent like kerosene (do not use carbon tetrachloride). Wash them in light machine oil, let the oil drain, and then repack with new grease.

The spring charging motor is designed to last for the life of the breaker under normal conditions. If replacement becomes necessary, follow these steps:

1. Turn the breaker on its right-hand side (as viewed from the front). Use wood blocks under the right-hand pole unit to hold it nearly level and to keep the shutter operating roller off the floor.

2. Remove the two bolts and the pipe plug located on the underside of the motor mounting plate. Also, loosen the nuts on the U-bolt on the underside of the mounting plate.

3. Withdraw the motor from the breaker.

4. To install, follow the steps in reverse order.

Under normal conditions, the closing spring should not need to be removed. If it becomes necessary due to unusual circumstances, proceed as follows:

1. Remove the idler link and pin.

2. Use a special fixture consisting of: a notched piece of 1-1/2 inch pipe (about 8 inches long), a piece of 1/2 inch diameter threaded rod (1/2-13, about 14 inches long), a thick washer (about 2 inches OD), and a 1/2-13 nut.

3. Place the notched pipe with the notch over the closing spring retainer pin.

4. Screw the threaded rod into the hole in the end of the connecting rod.

5. Place the washer over the end of the pipe.

6. Screw the nut on the outer end of the rod and tighten it against the washer. This will move the retainer plate away from the pin, taking pressure off it.

7. Remove the retainer pin by driving it out.

8. Unscrew the nut until the closing spring is completely free of compression.

9. Remove the special fixture and the spring.

10. To reassemble, perform these steps in reverse order.

If the porcelain insulation or the ceramic surface of the vacuum interrupter needs cleaning, follow these instructions:

• Wipe the surface with a dry, lint-free cloth or a dry paper towel.

• The surface can be washed with distilled water, but you must ensure it is completely dry before placing the breaker back in service.

• If a solvent is required to cut dirt, use Stoddard’s solvent (Westinghouse 55812CA or a commercial equivalent). Ensure the surface is completely dry before placing the breaker in service.

• Do not use any type of detergent to wash the porcelain surface, as detergents can leave an electrically conductive residue as they dry.

The following is a list of parts most likely to be replaced during normal maintenance. It is suggested that they be kept on hand for each breaker installed.