Filtering EMF/RF noise [RE-wrenches]

[Kurt Nelson]

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Free recipes to get you in shape
http://click.topica.com/caacVmfbz8Qcsbz9JC9a/PermissionData
-------------------------------------------------------------------

Greetings all,

I have recently installed a few off-grid PV systems wherein the home is
heated with in-floor radiant heat.  With the use of high efficiency DC
pumps the total electric load of the heating system can be as little as
20 watts when running and zero when the thermostat is satisfied.  

The problem is with the annoying static in FM radio reception when the
pumps are operating.  Brushed motors run the March 809 zone pumps and
the smallest, brushless El Sid pump circulates water through the heat
exchanger on the hot water heater.  I thought it would have been the
brushes, but it turns out it is the El Sid brushless motor making most
of the noise.

The filter I tried did nothing and was essentially a choke (10 ohm wire
wound resistor) and a diode (6A rectifier) in the positive line just
before a 4,700 mF, 35 volt electrolytic capacitor across the conductors
at the pump.

BTW, a portable, battery operated radio picks up the noise so the
interference is not on the power supply lines to the home's radios.  

Any thoughts greatly appreciated -- Kurt Nelson

Your free subscription is supported by today's sponsor:
-------------------------------------------------------------------
Are you serious about buying a NEW car or truck soon? 
Research before stepping on the car lot and save THOUSANDS!
Get NO OBLIGATION price quotes from car dealers in your area.
http://click.topica.com/caacVmkbz8Qcsbz9JC9f/LeadClick
-------------------------------------------------------------------

- - - -
To send a message: RE-wrenches at topica.com

Archive of previous messages: http://lists.topica.com/lists/RE-wrenches/read

List rules & etiquette: www.mrsharkey.com/wrenches/etiquette.php

Check out participant bios: www.mrsharkey.com/wrenches/

Hosted by Home Power magazine

Moderator: michael.welch at homepower.com
--^----------------------------------------------------------------
This email was sent to: michael.welch at homepower.com

EASY UNSUBSCRIBE click here: http://topica.com/u/?bz8Qcs.bz9JC9.bWljaGFl
Or send an email to: RE-wrenches-unsubscribe at topica.com

For Topica's complete suite of email marketing solutions visit:
http://www.topica.com/?p=TEXFOOTER
--^----------------------------------------------------------------