On 3/16/2011 3:20 PM, Charles Lewis wrote:
> I contacted Electrolux. Their response was that they had never heard of
> thatproblem. They only suggested I try grounding the cabinet. That is not
> practical.
Go back to square one and start over. FIRST, you are required BY LAW to
bond to ground the conductive enclosure of anything connected to mains
power. :PERIOD. This ground connection must be the green wire that MUST
be run with the power wiring, and connected to Equipment Ground in the
power panel that feeds it, which in turn must be bonded to ground at the
panel where power enters your building. These are the fundamental
requirements of building codes in all of North America, and in most of
the developed world. These are very well thought out requirements,
intended to protect against fire, electrical shock, and lightning -- to
do anything less is both unsafe and stupid.
Second, it is quite common for laundry appliances to be improperly
wired, both internally and externally, in a manner that can CAUSE
problems with hum, buzz, and RFI. Electrical codes (which carry the
force of law) require that a 240V appliance be connected ONLY to the two
Phase (Hot) conductors, plus the bond between the chassis and the Green
Wire. If there is something in the appliance that also requires 120V to
run (for example, a small motor), that 120V load MUST be connected
between one of the Phase (Hot) wires and the Neutral. Many electricians
cheat by connecting 120 volt loads in appliances between Phase and the
Green Wire. This is unsafe, illegal, AND likely to cause hum, buzz, and
RFI.
The chassis of the power entrance panel must be bonded to one or more
ground rods, and also to every other ground associated with your
building (telephone, CATV, ham shack, etc.). The word "bond" in this
context means a short, fat conductor connecting the required points.
SO -- the first thing you should do is study carefully what I've said
here, then verify that your laundry appliances are properly installed.
If they are not, call the electrician back and tell him to do it right.
And you should not PAY him to fix his mistake.
Once you know that the installation is proper, you're ready to figure
out if the manufacturer screwed up with RFI.
73, Jim Brown K9YC
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