We moved into our house a little over a year ago. It took me
several months before trying my Hf station on a temporary Alpha 1
antenna. The first day I did, I blew 4 Arc Fault breakers in the
main panel. It took me about 4 months to figure it out then a
few days ago I got this info from a friend from the ARRL. This
may also help some of you guys. The upshot was that I changed
out 4 arc fault breakers replacing them with regular ones and the
problems went away. Here's what the ARRL said about it. You
might find this interesting.
From today's ARRL newsletter
Your League: ARRL Helps Manufacturer to Resolve Arc Fault
Circuit Interrupter RFI Problems
The ARRL Lab has worked with a manufacturer of arc fault circuit
interrupter (AFCI) breakers to resolve complaints that Amateur
Radio RF was causing certain breaker models to trip
unnecessarily. Like the more common ground fault circuit
interrupter (GFCI), the AFCI is a safety device. Primarily
designed to detect problems that could result in a fire, AFCIs
detect potentially hazardous arc faults that result from often
unseen damage or poor connections in wiring and in extension
cords and cord sets.
"Several months ago we started receiving reports from amateurs
that when they transmitted, their AFCI breakers were tripping,"
said Mike Gruber, W1MG, the ARRL Lab's EMC specialist. He noted
that the issue has been a topic of online ham radio discussions
as well as on homeowner sites; it seems that stray RF is not the
only thing that can cause a "nuisance trip" of an AFCI. Gruber
pointed out that the National Electrical Code (NEC) already
requires AFCIs in some household circuits, but not all US
jurisdictions have adopted the requirement.
W1AW Station Manager Joe Carcia, NJ1Q, with the AFCI test
stand. [Mike Gruber, W1MG, photo]
Gruber said that as AFCIs became more common in new construction
in the US, reports started coming in that AFCIs in the vicinity -
not just in the radio amateur's home - would trip in the presence
of RF from an Amateur Radio transmitter. While each
manufacturer's design is proprietary, most AFCIs detect arcs by
monitoring the shape of the alternating current waveform, changes
in current levels, voltage irregularities, and the presence of
high frequency emissions or "noise." The ARRL Lab dug into the
problem.
"Last summer we built a test fixture in which we could test any
type of circuit breaker," Gruber said. It involved using W1AW as
an RF source. Gruber said he bought one of "every AFCI that I
could get my hands on," but when the Lab began testing them
during W1AW transmissions, none of the devices tripped..
A ham in New Mexico who had reported AFCI problems sent some of
his breakers to the ARRL Lab, "and those tripped when we tested
them," Gruber said. The problematic breakers were certain models
made by Eaton Corporation. "We already had an Eaton breaker, an
older model, but it did not trip," he noted, adding that the
breaker had a yellow button. The newer model, which had a white
button, did trip in the presence of RF, however, even at power
levels down to about 50 W on 17 meters.
Gruber contacted Eaton, and two of the manufacturer's engineers
visited ARRL Headquarters in August. "Eaton was extremely
cooperative and eager to resolve this," Gruber recounted. "They
spent the day with us, going over our test methods and took some
of the problematic breakers back with them, eventually developing
a modified version.
"We have just finished testing the new version of the breaker,
and it did not trip during W1AW transmissions and in other
tests," Gruber reported. He said the new breaker is still in the
queue for UL approval.
Eaton Engineering Director Andy Foerster said arc fault detection
is challenging, in part because so many common household devices
- such as vacuum cleaners and power tools that use motors with
brushes - create arcing. In information provided to ARRL Eaton
engineer Lanson Relyea said that because AFCIs rely on HF
emission detection to verify arcing, "any signal that conducts or
radiates a signal within the detection band of the AFCI can cause
interference and cause the device to trip without the presence of
a true arcing condition."
Eaton and ARRL agreed that when the manufacturer comes out with
any new models of breakers, it will ask the League to test them
at W1AW. "It's a win-win situation," Gruber said. Eaton also
has agreed to work with anyone having a problem with RF tripping
its AFCIs.
Hams experiencing unwanted tripping problems with their or their
neighbors' AFCIs should first contact the manufacturer. In the
case of Eaton breakers, contact Bob Handickgg412-893-3746) or Joe
Fello (412-893-3745). Read more.
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