[RFI] Honda Generator RFI?

Jim Brown jim at audiosystemsgroup.com
Sat Sep 16 19:50:31 EDT 2006

On Sat, 16 Sep 2006 18:00:58 -0400, Alan NV8A wrote:

>OTOH, I've read suggestions by licensed electricians and electrical 
>inspectors suggesting that all these Hondas should be red-tagged 
>they are not and cannot be properly grounded in accordance with the 

Those electricians may be trying to apply residential standards to 
outdoor portable systems, and they may not apply. Someone more familar 
with NEC can probably enlighten us further. 

Note that the BOND to EARTH is solely for lightning protection, and for 
other high voltage faults that come in on the power line. This is far 
less of an issue for wiring that mostly lays on the ground. 

Bonding of the green wire at each outlet is to the neutral back at the 
panelboard or other distro. This is to prevent electric shock, and for 
fire safety -- the purpose of the green wire is to blow a fuse if the 
chassis something plugged into an outlet gets "hot" due to a fault.  

There is nothing inherent in a generator that would preclude you from 
connecting it to a suitable panelboard or distro that bonds neutral to 
green and earth, which then takes care of both kinds of bonding. 
Further, let's say you do a changeover switch at your residence to take 
power from that generator. If you tie the generator in to the same point 
where the incoming power comes in (via the transfer switch), you would 
still meet code. Unless there's something I'm missing. 

W4EF's advice, posted via a link by someone else in this thread, is 
solid. Mike knows what he is talking about.  One thing I would add to 
his advice, which is probably a couple of years old, is that the newer 
Fair-Rite #31 mix would do a much better job of filtering the lower HF 
bands. And with either #43 or #31, you MUST wind a bunch of turns as he 
as shown in his photo. For more detail on this, see the app notes on 
ferrites on my website. 


Another point. Mike's common mode choke gets only the common mode trash 
-- that is, the AC line radiating as a long wire antenna. If the RF is 
getting onto the line itself (that is, between hot and neutral), you 
would also need a good line filter. AND -- it must be the right kind of 
line filter, it must be right next to the noise source, and it must be 
bonded (NOT earthed) to the frame of the noise source. By "the right 
kind of filter," I mean that it needs to be configured to block noise 
from the generator to the load, rather than the other way around, and it 
must be designed to be effective over the frequency range that is 
bothering you. In other words, there are line filters, and there are 
line filters. 


Jim Brown K9YC

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