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Aluminum Wiring Hazards
Aluminum single strand wiring
(10 gauge,
rated 20 amps and 12 gauge
rated 15 amps), was used
from 1965 to 1974 although I have seen a few
homes where a few coils of aluminum wiring were used after
those dates.
Is aluminum wire a hazard? No
it is not. However the connections are a known
fire hazard. When aluminum wiring gets hot
it expands, aluminum wiring cools it contracts creating
the potential for a loose connection that allows
more heat to develop the next time current is
drawn on the circuit.
During home inspections we perform we use a sophisticated
electrical testing device that actually puts circuits
under a load. Loose connections, corroded
connections and connections that are likely to
get hot are frequently found with this special
and expensive meter, few inspectors use.
Make sure the inspector you pick is testing for
voltage drop as well as the resistance of the
wiring at electric receptacles. While the
method we use is far from perfect it is far
superior to the cheap 3 light testers required
by the very minimal state of NJ
standards.
For those of you who remember high school science
when you heat things they usually expand, when
they cool they contract. As aluminum
wiring gets hot it expands against the screw
that holds it in place, when it cools it
contracts and a microscopic gap between the
connection and the wire occurs. Over time
the connection oxidizes and develops more
resistance and eventually it gets hotter and the
gap and corrosion continue to occur.
Eventually the aluminum wiring connection can get hot enough to
ignite inside the wall. A house fire is frequently
the result. Installation of special wire
nuts is not a recommended solution because other
problems may occur. A solution that may
help is the installation of special crimp on
connectors. The AMP
Corporation designed a wire
crimping tool and system
that will provide
dependable results with
aluminum to copper
connections. The crimp is
designed to ensure that air
does not come between the
aluminum and copper. After
the connection is crimped,
it is covered with a
sleeve, which is shrunk
around the connection. This
process minimizes oxidation
at the contact.
This is the
only system that the
Consumer Product Safety
Commission (CPSC) has
accepted.
1. The CPSC does
not recognize any other
system or correction as
acceptable. This creates
legal concerns for anyone
who may recommend a
different solution.
2. AMP
Corporation does not sell
the crimping tool; they
have patents pending and
only allow users to lease
the equipment. This limits
access for residential or
small work, because it is
difficult to justify
leasing costs for one
home.
3. The number of
“qualified”
electricians that have gone
through the AMP training
creates further
limitations. There are very
few electricians in the
country that have gone
through the training and
most are commercial
electricians. To read the information the
CPSC has made available about aluminum wiring go
to aluminum wiring.pdf
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