4
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
Isolation Switch
Main Fuses
Isolation Switch
Operating Handle
Main Contactor
CPT/PT Primary Fuses
CPT
PTs
Figure 3. Medium Voltage Compartment
m
caution
main fuses weigh 44 pounDs for the 400a-15bhcls-400.
Low voltage components
The low voltage components consisting of a protective relay,
interposing relay, test power circuit, terminal blocks, and optional
equipment are mounted in the low voltage control compartment
located on the front of the controller medium voltage door . The low
voltage compartment is fabricated from steel sheets to provide
isolation from the medium voltage components mounted behind the
low voltage compartment . A window is provided in the low voltage
compartment to allow the user to view the position of the isolation
switch before entering the medium voltage compartment . See
section on Isolation Switch for further details .
Figure 4. Low Voltage Compartment
Isolation switch
The controller isolation switch is a non-loadbreak device .
Mechanical and electrical interlocks are provided to ensure that the
main contactor is de-energized before the switch can be operated .
In the open position, the switch isolates medium voltage from the
main controller compartment, allowing access to the controller for
inspection and maintenance . For standard applications, the isolation
switch includes ground fingers that ground the line side of the
power fuses when the switch is in the open position .
m
Danger
ampgarD controllers are sometimes energizeD by a back-feD
conDition that allows the meDium voltage compartment to
be energizeD with the isolation switch in the open position.
stuDy the plant single-line Diagrams to make certain that
no back-feeD situation exists before entering the meDium
voltage compartment.
all power sources must be isolateD anD lockeD out before
servicing the equipment.
for applications where the controller is back feD,
the grounDing fingers shoulD be removeD from the
isolation switch.
The switch consists of a fixed rear portion and a removable front
portion . Refer to
Figure 6
and
Figure 7
. The fixed portion includes
the controller line fingers and a moveable shutter that isolates the
line fingers when the switch is in the open position . The removable
portion is operated by a handle mechanism that extends through the
controller medium voltage door . With the handle in the up position,
the switch is closed, and medium voltage is available for connection
to the controller load . With the handle in the down position, the
switch is open, and medium voltage is isolated from the controller
and the controller load .