5
Instruction Booklet
IB48088
Effective July 2021
Instructions for Eaton’s 7.2 kV Ampgard AR
(arc resistant motor control center)
(Compliant to IEEE C37.20.7-2017)
EATON
www.eaton.com
Figure 4. Location of the bolts to be removed.
5. Power fuses will be accessible at this point.
6. To remove them, begin with removing the four mounting nuts
and the flat washers. Before taking the last nut off, make sure
you have one hand on the barrel of the fuse as it may have the
tendency to tilt towards you.
7. Grab the barrel of the fuse and move it straight towards you.
Depending on the size/weight of the power fuse, you may need
to use both hands. The fuses weights can vary front 8 to 36 lbs
(3.63 to 16.33 kg).
Figure 5. Power fuses with service barrier removed.
8. If the starter is equipped with a blown fuse indicator option, the
indicator arms will be visible hanging from the back. Push the
arm assembly all the way to the top. You will hear a click sound
and the arms will stay up against the top barrier. See item 11 to
reset the blown fuse indicator.
9. Follow the above steps in the reverse order to install the fuses.
10. Torque the fuse mounting nuts to 20 ft-lb (27.12 N·m).
11. Once the fuse are in place, reach above the top Ferrell of one of
the fuses and pull the blown fuse indicator down to rest on top
of the fuse Ferrell. You will hear a click.
12. Reposition the service barrier and reinstall the six bolts. Tighten
until the lock washers are flat.
In order to check the health of the fuse, one does not have to take
the service barrier off. There are 1/8 inch diameter holes in the clear
Lexan piece attached to the bottom of the isolation switch for the
multimeter probes to touch the line side of the fuse copper mount-
ing piece for each phase as shown in
Figure 6. Multimeter probe access points with service barrier in
place.
1.5.3 Handle mechanism and safety interlocks
The handle mechanism and the safety interlocks are the same as
described in IB48041.
1.5.4 Low voltage control compartment
The customer terminal blocks are located in the starter compart-
ment. Wiring from this terminal block to the low voltage compart-
ment is done in the factory.
If additional wiring needs to be routed to the low voltage compart-
ment, start by removing the conduit sealing gasket from the front
conduit hub. Route additional wires thru the conduit hub into the
low voltage compartment. Bundle wires together and wrap it with
conduit sealing gasket where it passes thru the conduit hub (if
possible, at least 1 ½ times around the wire bundle). Place a wire
tie on each end of the gasket.
Isolation
switch
Mounting
nuts
Power
fuse
Power fuse
service barrier
Isolation
switch
Six bolts
