11
Instructional Leaflet
IB48041
Effective December 2009
Instructions for AMPGARD 400A
medium voltage starter
eaton corporatIon
www.eaton.com
Figure 29. Bolts Securing ISo Switch
The fixed portion of the switch, including the isolating shutter,
remains in the controller. Medium voltage may be present at the
line fingers behind this shutter. Before attempting to inspect the line
fingers or do other work on the fixed portion of the switch, ensure
that the controller incoming power is isolated and locked out at an
upstream feeder.
With the incoming power locked out, the fingers can be inspected
and the vertical bus connections checked for tightness. Remove the
polyester barrier mounted immediately below the switch for access
to the vertical bus connections. Verify the operation of the shutter
mechanism by gently pushing it to the left. It should spring back
to the closed position when released. After 5000 operations, the
fingers and stabs should be relubricated with Dow DC4 high-
temperature dielectric compound.
Danger
failure to lock out incoming power before servicing the fixeD
portion of the switch or vertical bus can result in equipment
Damage, severe injury, or Death.
Figure 30. Fixed Isolation Switch
Reinstallation is the reverse of the procedure previously discussed.
Make sure that the shaft of the removable portion of the switch is
rotated to the fully open position before reinstallation.
Danger
if the switch is inserteD with the shaft in the closeD position,
the shutter may be forceD open anD live parts may be contact-
eD, resulting in severe injury or Death.
Door interlock
A mechanical interlock prevents opening the medium voltage door
with the switch in the closed position. A steel plunger lowers into
position as the switch is closed. This plunger engages a bracket
welded to the back of door, preventing the door from opening with
the switch closed. In the unlikely event the switch malfunctions and
cannot be opened, it will be necessary to drill out the welds to allow
access to the medium voltage compartment. Refer to
Figure 31
.
Use a 1/4-inch bit and drill out the two welds that can be seen just
below the handle mechanism. After repairs are made to the switch
mechanism, the door should be replaced with a new factory-built
part to ensure the restoration of the interlock feature.
Figure 31. Drill Location for Emergency Entrance to
Medium Voltage Compartment
Shutter
“Barber
Poles” (3)
Visible when
Shutter is
Closed
Remove
Barrier for
Access to
Vertical Bus
Connections
(incoming
power must
be locked
out first)
Drill Out
Welds for
Emergency
Access
Bolts (2) Securing
Removable to
Fixed Portion
of Switch
