6
Instruction Booklet
IB48050
Effective September 2012
Instructions for installation,
operation, and maintenance of the
AMPGARD 15 kV, 300A vacuum starter
eaton Corporation
www.eaton.com
Vacuum contactor
300A, 15 kV AMPGARD medium voltage controllers are supplied
with 300A vacuum contactors . The contactor has an interrupting
rating of 5000A and is open-rated to carry 300A continuously .
The contactor enclosed rating is also 300A .
Figure 9. 300A, 15 kV SL Vacuum Contactor
Contactors are typically three-pole devices except in the case of the
start contactors on autotransformer starters, which are normally
two-pole devices .
Refer to Instruction Book IB48051 for further details on the operation
and maintenance of the vacuum contactors .
Controllers supplied as transformer feeders or for other specialized
applications are sometimes supplied with contactors that include
a mechanical latch device . Refer to Eaton for further details on the
operation and maintenance of the latch mechanism .
Safety interlocks
AMPGARD controllers are manufactured with several built-in
interlock provisions and safety features to reduce hazards and
provide proper operating sequences .
A mechanical interlock prevents opening the medium voltage door
with the switch in the closed position . Ensure that the medium
voltage door is fully closed and latched using the two latches on the
right side of the door to prevent damage to the interlock bracket on
the back of the door .
An additional interlock prevents closing of the switch unless the
medium voltage door is closed (see MV door interlock plunger
in
Figure 10
) . On controllers that require two structures (reduced
voltage starters for example), the door to the second structure
will also be interlocked with the switch operating mechanism . The
second door must be closed before the main door is closed . Both
doors must be closed before the switch operator can be moved to
the closed position .
otee:
N
Attempting to close the switch with the door open can cause damage
to the operating mechanism .
Isolation
Switch
Drive Rod
MV Door Hold-Down Interlock
Contactor
Interlock
Rod
MV Door
Interlock
Plunger
Pilot Hole
for Creating
Optional
Provision to
Lock Switch
Closed
Padlocking
Provisions
(Switch
Open)
Figure 10. Handle Mechanism with Contactor and Door Interlocks
Mechanical and electrical interlocks are provided to insure that the
non-loadbreak isolation switch cannot be opened or closed unless
the main contactor is de-energized (see contactor interlock rod in
Figure 10
) . Do not attempt to force the switch operating mechanism
with the main contactor closed . The handle mechanism is designed
to fail before the isolation switch can be opened with the main
contactor closed .
m
caution
applying excessive force to the switch hanDle with the
mechanical interlocks engageD will result in Damage to
the switch.
An electrical interlock is provided to disconnect the control power
transformer secondary before the isolating switch stabs are
disconnected from the controller line fingers . This interlock ensures
that the switch is breaking transformer magnetizing current only .
Do not connect additional loads to the controller isolating switch .
m
Danger
if loaDs greater than the interrupting rating of the switch
are connecteD to the switch, equipment Damage, personal
injury, or Death may occur.
An optional key interlock may be provided to lock the switch in the
open position for special configurations . Refer to the specific order
drawings to determine if key interlocks have been provided .
On reversing, two-speed or autotransformer type starters,
mechanical interlocks are provided to prevent two or more
contactors from closing at the same time .
