Eaton 36W-VAC25, Instructions For Installation, Operation And Maintenance

I.B. 3A74499B

Page 23

Effective 11/97

Device coil has at least 85% of the rated voltage
applied, the moving clapper is held to the yoke by the
magnetic force,even though the reset lever has moved
up.

5-4  INTERLOCKS

NEVER DISABLE OR DEFEAT ANY INTERLOCKS.
HAZARDOUS VOLTAGES WILL CAUSE DEATH,
SEVERE PERSONAL INJURY OR PROPERTY DAM-
AGE.

All W-VAC breakers are equipped with several inter-
locks. These interlocks permit proper and safe breaker
operation.

5-4.1  FLOOR TRIPPING, SPRING RELEASE AND
ANTI-LATCH  INTERLOCKS

These interlocks are operated by the inter- action
between the floor tripper rollers on the breaker bottom
and the carriage or cradle assemblies. The functions
performed are as follows:

1.  The breaker is held mechanically trip free during

racking. The latch check switch is also held open,
thus preventing any electrical close signal from clos-
ing the breaker.

2.

The breaker is permitted to be with drawn in the
safe mode (breaker open, springs discharged) when
bringing the breaker to the Withdrawn position or to
the Connected position.

The outlined functions are accomplished by pushing up
the tripper rollers, which in turn rotates the Trip D Shaft
or Spring Release Latch.

5-4.2  LEVERING INTERLOCK

The purpose of this interlock is to prevent the levering
crank from being engaged when the breaker is closed.
An interference device on the cradle or carriage, which
is positioned by the breaker operating shaft, prevents
the levering crank from being inserted with the breaker
in the Closed position.

5-4.3  ANTI-CLOSE INTERLOCK

This interlock prevents releasing the closing springs
electrically or manually, if the breaker is already closed.
On a closed breaker the interlock lever moves toward
the rear. In this position the movement of the spring

release clapper does not lift the lever, thus the spring
release latch cannot be moved.

5-4.4  EARTHING DRIVE INTERLOCK

The earthing drive mechanism operates an interference
device to prevent insertion of the breaker when the
earthing switch is closed.

5-5  MISCELLANEOUS

5-5.1  EARTHING CONTACT

The earthing contact is an assembly of spring loaded
fingers providing a means for earthing the breaker chas-
sis when it is inserted into the switchgear compartment.
An extension of the switchgear earth bus is secured to
the compartment in such a position to engage the earth-
ing contact when the breaker is racked into the struc-
ture.  It remains engaged until the breaker is withdrawn.

5-5.2  OPERATIONS COUNTER

All breakers are equipped with a mechanical operations
counter. As the breaker opens, the linkage connected to
the pole shaft lever advances the counter reading by
one (Figures 3-2 and 3-3).

5-6  LEVERING MECHANISM

The purpose of the levering device is to move the break-
er into and out of the CONNECTED position. For W-
VAC breakers, the mechanism is comprised of a drive
screw and nut. The mechanism is a part of the carriage
assembly or the cradle assembly, not the basic breaker
element (Figures 3-5 and 3-6).

!

WARNING