Advertisement
7-1 Visual Inspection
Visually inspect the circuit breaker for any signs
of damage or loose hardware.
7-2 Closing Spring Charging
Manually charge the breaker closing spring us-
ing the charging handle provided. (Figure 7, Item
1) The closing spring is charged by a
ratcheting mechanism that advances one
ratchet tooth at a time. Approximately eight
complete strokes are required. When the spring
is fully charged, the spring load is held by the
closing latch. The spring indicator (Figure 1,
Item 5) changes from "DISCHGD" to
"CHARGED", and a positive snap is heard as
the spring travels over center.
CAUTION: AFTER THE SPRING IS COM-
PLETELY CHARGED, AS INDICATED ABOVE,
FURTHER FORCING THE CHARGING
HANDLE MAY CAUSE DAMAGE TO THE
CLOSING LATCH AND ITS ASSOCIATED
PARTS.
7-3 Closing Spring Gag
Remove the mechanism front and top covers
and insert the tip of the closing spring gag tool
(Figure 22, Item 2) between the end of the spring
and the spring guide, engaging the détentes
(Figure 22, Item 3) on the gag tool into the slots
in the closing spring guide. (Figure 22, Item 4)
Reference also Figure 48.
With the gag tool in position depress the
manual close button. This action will partially
discharge the closing spring and also partially
close the vacuum interrupter contacts.
CAUTION: DO NOT REMOVE TIE BAR (FIG-
URE 18, ITEM 1) UNLESS SPRING HAS BEEN
REMOVED FROM THE BREAKER.
CAUTION: DO NOT ENERGIZE THE SEC-
ONDARY CONTROL CIRCUIT AT THIS TIME.
USE OF THE GAG TOOL SHOULD ONLY BE
ATTEMPTED WHEN THE BREAKER IS OUT
Courtesy of NationalSwitchgear.com
Chapter 7. Mechanical Checking and Slow Closing
4
25
PowerVac
5kV Vertical Lift
®
7-4 Slow Closing
To manually slow close the breaker contacts,
remove the top plate of mechanism. Install the
closing spring gag, as described above. Put the
manual charge handle on the manual charge
lever and move the handle up and down. The
breaker will be fully closed when the spring
charge indicator shows "CHARGED"
CAUTION: WITH THE GAG TOOL INSTALLED,
THE BREAKER CLOSED, AND OPENING
SPRINGS CHARGED, THE BREAKER CAN BE
TRIPPED AT FULL SPEED.
1
1 Tie bar
4 Closing spring guide
2 Gag tool
5 Spring pin
étentes
3 Gag tool d
6 Closing spring
Figure 22. Closing spring with gag tool
inserted
7-5 Gag Tool Removal
To remove the gag tool, the closing spring must
be fully charged. If the spring charge indicator
does not show "CHARGED" in the window,
manually charge the spring until it does. Lift up
and push down and away on the gag tool to
clear the détentes on the gag tool from the slots
in the closing spring guide. For safety, first close
the breaker by depressing the manual "CLOSE"
button and then depress the manual "TRIP"
button. All stored energy is now removed from
the breaker.
2
3
5
6
Advertisement
