FEDERAL PIONEER H-3, Instructions For The Care And Maintenance

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FIG. 7.3.13 TOGGLE PIN.
1. STOP IN MECHANISM SIDEPLATES
2. TOGGLE PIN
FIG 7.3.14.1 CONTACT DIFFERENTIAL.
1. SHIM
2. FIXED ARCINC CONTACT MOUNTING SCREW
FIG. 7.3.1 2.6 DRAWOUT CONTACT LUBRICATION
13. CHECK CLOSING MECHANISM TOGGLE
NOW, CHARGE AND CLOSE THE BREAKER AND OBSERVE THE
POSITION OF THE TOGGLE PIN. THIS IS BEST DONE BY LOOKING
DOWN INTO THE CLOSING MECHANISM FROM ABOVE. IN THE
CLOSED POSITION, THE TOGGLE PIN MUST REST AGAINST THE STOPS
IN THE MECHANISM SIDEPLATES.
IF THE PIN IS NOT AGAINST THE STOPS, ADJUSTMENT OF THE
ECCENTRIC MUST BE DONE BEFORE CONTINUING. REFER TO SECTION
8.1 FOR DETAILED INSTRUCTIONS.
14. CHECK DIFFERENTIAL
AS THE MOVING CONTACT CLOSES, THE ARCING CONTACTS
TOUCH FIRST. AT THIS POINT, THE UPPER CAP BETWEEN THE MAIN
CONTACTS IS TERMED CONTACT DIFFERENTIAL. AS THE MOVING
CONTACT CONTINUES, THE ARCING CONTACT BRACKET ROTATES TO
BEGIN COMPRESSING THE WAFER SPRINGS. AFTER THE MAIN
CONTACTS HAVE TOUCHED, THE FRAME OF THE MOVING CONTACT
CONTINUES TO MOVE. THE OVERTRAVEL OF THE FRAME RELATIVE TO
THE WAFER CONTACT IS TERMED THE CONTACT DEFLECTION. THIS
OVERTRAVEL ALLOWS THE WAFER CONTACTS TO BE FREE FLOATING
AND SELF-ALIGNING, HELD AGAINST THE STATIONARY MAIN
CONTACTS BY ONLY THE FORCE OF THE WAFER SPRINGS.
BEGIN BY CHECKING THE CONTACT DIFFERENTIAL. WITH THE
MAIN SPRING DISCHARGED AND THE CONTACTS OPEN, MANUALLY
PUSH THE CONTACTS CLOSED UNTIL THE ARCING CONTACTS TOUCH.
THIS IS MOST EASILY DONE USING A SLOW CLOSE DEVICE. THE
ARCING CONTACTS OF EACH POLE MAY NOT TOUCH AT EXACTLY THE
SAME TIME, SO CHECK EACH POLE SEPARATELY ENSURING THAT THE
ARCING CONTACTS ON THAT POLE ARE TOUCHING. USING A FEELER
GAUGE, CHECK THE UPPER GAP BETWEEN THE MAIN CONTACTS. THE
NORMAL CONTACT DIFFERENTIAL IS BETWEEN 50 AND 65
THOUSANDTHS OF AN INCH, THOUGH HIGHER DIFFERENTIAL
READINGS ARE ACCEPTABLE AS LONG AS THE TOGGLE PIN IS
AGAINST THE STOPS WHEN THE BREAKER IS CLOSED. IF THE
DIFFERENTIAL IS TOO LOW, IT CAN BE INCREASED BY REMOVING THE
STATIONARY ARCING CONTACT AND ADDING A SHIM UNDERNEATH
IT. CHECK EACH POLE FOR DIFFERENTIAL. IF ANY SHIMS ARE ADDED,
BE SURE TO CHANGE AND CLOSE THE BREAKER AND CHECK THAT
THE TOGGLE PIN IS STILL AGAINST THE STOPS.
Courtesy of NationalSwitchgear.com