Página 638 - BURNDY

Versión de HTML Básico

CONNECTORS FOR
ALUMINUM CONDUCTORS
Bolted aluminum connectors are cast of alu-
minum alloy and assembled with aluminum
alloy bolts, nuts and galvanized steel
washers. The hex head bolts are captured for
one-wrench installation. The connectors
accommodate aluminum or copper conduc-
tor. The “mass anode” design pioneered by
BURNDY
®
minimizes the effect of galvanic
corrosion on aluminum (anode+) connectors
when used with copper (cathode –) conduc-
tor (Reference Fig. 1).
Joint deterioration caused by relaxation or
“cold flow” of the aluminum is eliminated by
the massive design. Generous contact areas
distribute clamping forces evenly over the
conductor, eliminating points of high stress
that cause “cold flow.” These contact areas
are factory treated to remove surface oxides
and coated with an oxide inhibitor to prevent
their reformation. Large radiating surfaces
allow the connectors to run cooler than the
copper conductor compensating for the fact
that aluminum has a higher coefficient of
thermal expansion. Connector and conduc-
tor expand and contract together during load
cycles, eliminating stresses on the aluminum
body that can cause relaxation of the joint.
CONNECTOR SELECTION
Generally, copper connectors are recom-
mended for copper conductor and aluminum
connectors for aluminum conductor. Where
aluminum connectors are recommended for
use on both aluminum and copper conduc-
tors, the copper must be positioned parallel
to or below the aluminum to prevent contam-
ination of the aluminum by copper salts
washed down by rain.
Except where indicated, all rigid connectors
accept standard or extra heavy I.P.S. and all
flexible connectors standard I.P.S. If extra
heavy I.P.S. is to be used with a flexible joint,
it must be spelled out at the time of ordering
so that the proper cross sectional area of the
flexible element may be supplied for the
increased conductor rating.
CONDUCTOR PREPARATION
To obtain optimum performance from any
connector, the conductor surface must be
thoroughly cleaned before installation. The
surface oxides that form on all conductors
act as insulation. Failure to remove them
can result in high resistance joint and, ulti-
mately, failure.
Conductor contact surfaces should be
scratch brushed until bright and shiny.
Aluminum conductor (new or old) should be
coated with BURNDY
®
PENETROX™ after
scratch brushing. PENETROX™ is a joint
compound that aids in the establishment of
low resistance joints and prevents aluminum
oxides from reforming.
ALUMINUM INTRODUCTION
Fig. 1
Many aluminum ions
removed by current flow
Few aluminum ions
removed by current flow
Copper Cathode
Aluminum Anode
Aluminum Anode
Copper Cathode
L-22
Blue highlighted items are industry standard and most frequently ordered.
Canada: 1-800-387-6487
www.burndy.com
US: 1-800-346-4175
Substation — Bolted
BURNDY
®