27
Electrical Connections
Bus Joint Insulation - Boots
Standard and repetitive bus bar joints are normally provided
with insulation boots installed at the factory. See
Figure 20
.
After they are completed in the field, bus bar joints at shipping
splits must be insulated as part of the total insulation system.
Normally, boots are provided for field completed shipping split
joints and are shipped in the location where they will finally be
installed. See
Figure 21
.
Grommets are provided for use with the boot when the bus
bar is smaller than the opening in the bus bar boot. When
required, these grommets are normally mounted along with
the bus boot in the final assembly location.
Before removal of the boot to complete the joint, observe the
location and orientation of the boot and hardware. This should
make reinstallation easier.
Nylon nuts and bolts and flat washers, or reusable plastic rivets
are used to hold the boot closed after it is installed. Some boots
may use molded-in threaded stems to provide a snap type clo-
sure. Carefully remove the insulation boot and save all hardware.
After the bus bar joint has been properly assembled, reinstall
the insulation boot. Secure the boot closed with the nylon nuts
and bolts. Completed boot installation should be flush with the
bus bar insulation and overlap it by at least 1-1/2“ (38mm). In
those cases where the boot does not close flush with the bus
bar insulation or the overlap is less than 1-1/2” (38mm), apply
one layer of tape (15-171-987-001) 1/2 lapped, overlapping the
bar insulation and boot by 1-1/2” (38mm).
Figure 20.
Typical Installation of Insulating Boot
THICKNESS
OF BUS
THICKNESS OF
INSULATION
ON BUS
BOLTING CAVITY ALLOWS FOR
FULL OVERLAP OF TAP OR SPLICE
PLATE AND FOR ANY NUMBER OF
CONNECTION BOLTS USED.
CONNECTION BOLTS
MINIMUM (4)
1/2" DIAMETER
RECOMMENDED
CENTER TAP
BUS
BUS
TAP
BOOT CLOSING
FLAPS SECURED
WITH PLASTIC RIVETS
OR NYLON HARDWARE
WIDTH OF
INSULATION
ON TAP
WIDTH
OF TAP
WIDTH OF
INSULATION
ON BUS
WIDTH OF
BUS BAR
GROMMET
GROMMET
GROMMET
GROMMET
GROMMET
GROMMET
NOTE: GROMMETS ARE PROVIDED
AND MUST BE USED WHEN
BUS BAR IS SMALLER THAN
OPENING PROVIDED IN BOOT
INSTALL PLUG (PROVIDED)
IN UNUSED BOOT OPENING
