And, since were talking about electrical panels and washing machines,
NEC states that the laundry must have a dedicated circuit for the
washing machine, with it's own dedicated neutral and ground wire all the
way back to the load center panel and dedicated breaker for that
circuit. Sorry, my copy of NEC is at work, so I can't quote the section.
Maybe someone else who has a copy of the NEC, or has paid the
subscription to view it online, can check and confirm whether I
completely correct on this.
DE N6KB
CSM(r) Gary Huber - AB9M wrote:
And if you have more than one electrical panel, only the first panel (Main
Distribution Panel) has a Neutral - Ground bonding screw in place. All sub
panels are to have the neutral - ground bonding screw removed (frequently
not done).
73,
Gary - AB9M
--------------------------------------------------
From: "Jim Brown K9YC" <k9yc@audiosystemsgroup.com>
Sent: Wednesday, February 03, 2010 4:14 PM
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Subject: Re: [TenTec] High speed washer hum/whine
On Wed, 03 Feb 2010 15:27:36 -0600, Stuart Rohre wrote:
The problem may be Variable
Speed Drives in the appliance, lots of modulated semiconductors
controlling the motor for "Green" efficiency. Oh, the laws of
unintended consequences from the environmentalists!
Don't blame environmentalists -- it's lousy circuit design.
There are no guarantees with line filters.
This doesn't sound like a line filtering issue, but it DOES sound
like possibly improper connections of neutral and the power system
green wire, or a missing power system green wire, of missing bonds
of station ground to the rest of what's grounded. These improper
connections could be in the shack or at the appliance.
Some things to check. 1) Make sure that the green wire is bonded
to the chassis at the power supplies, AND where the power supply
is plugged into the AC outlet. 2) Make sure that the chassis
(green wire) is NOT connected to the neutral. 3) Make sure that
your power system ground (green wire) is bonded to everything else
in your station, and that every chassis in your station is bonded
together. 4) Make sure that the common point of your station
chassis bonds (grounds) is tied to the ground rods for your
antenna system, your shack, the power system ground rod, and the
ground for Telco and CATV arrestors.
Look for #1 and #2 at the appliance that is generating the noise.
73,
Jim K9YC
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