"Mark" wrote in message
oups.com...
modelman wrote:
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM
broadcast reception throughout my house. I also see snow on a TV
connected to an external antenna.

The radio noise occurs as soon as the draft inducer motor starts up;
the pitch of the interference is related to the motor speed. The draft
inducer motor is a dc motor driven by a PWM controller on the main
circuit board. It is well known that PWM systems generate strong
harmonics throughout the radio spectrum, resulting in radio
interference. However, properly designed PWM systems include filtering
and shielding to suppress the radio frequency currents from the wiring.

I contacted my installer, who is totally unfamiliar with the problem.
The electrician who was sent to my house to investigate the problem
also doesn't understand what's going on. I had to explain the
difference between an RF ground and dc or house ground to him.
Although everything appears to be well grounded from a dc perspective,
I suspect that portions of the system are radiating RF energy.

Several days ago I emailed Trane about the problem, but haven't
received any response.

Although there has been past discussion in this group about radio/TV
interference emanating from Trane high efficiency gas furnaces, I
haven't seen any definitive fix. Does anyone know if Trane has a fix
for this problem. Do they have a shielded cable and or rf filter kit
to suppress this noise? Since my system is under warranty, I won't
attempt any modiifcations to the system.

Has anyone experienced this problem?

Thanks.


Trane should be made to fix this and recall all the units that have
been installed. I can pick this interference up on a 2 meter receiver
in my car for blocks. The FCC should bust them if they don't fix it...

I cross posted this to some of the amateur radio groups.

Mark

with the punce gotcha do u hav anyting cognet two say?



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Posted via a free Usenet account from http://www.teranews.com

Hi again Mark,

I think Jake is on the right track, whatever the source of noise inside the
unit its the mechanism that radiates the noise that needs to be attended to.
In my case it was the external cables, choking them off with ferrite sorted
out my problem. To suppress the noise at source within the unit seems a bit
hard for me. I also suspect there may be more than one noise source in the
box.

73 Alan VK6BN


"Mark" wrote
Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM

Alan Taylor wrote:

Hi again Mark,

I think Jake is on the right track, whatever the source of noise inside the
unit its the mechanism that radiates the noise that needs to be attended to.
In my case it was the external cables, choking them off with ferrite sorted
out my problem. To suppress the noise at source within the unit seems a bit
hard for me. I also suspect there may be more than one noise source in the
box.

73 Alan VK6BN


"Mark" wrote

Several months ago I had a high efficiency Trane XV90 natural gas
furnace and heat pump installed. Since the weather has recently been
cold enough for the gas furnace to provide heat, I have been
experiencing severe radio interference. The interference wipes out AM



Hi,
Then, shielding, choking, bypassing with caps come to mind. It's all by
trial and error. O'scope may come in handy.

Hi,
Then, shielding, choking, bypassing with caps come to mind. It's all by
trial and error. O'scope may come in handy.

Well that's my concern.
There are more and more of these kinds of units being installed
everyday.
We can't "home brew" a fix for all of them.
Someone needs to get to the FCC or to the manufacterer to fix this at
the source before it gets worse.

Mark

"Mark" wrote in message
oups.com...


Well that's my concern.
There are more and more of these kinds of units being installed
everyday.
We can't "home brew" a fix for all of them.
Someone needs to get to the FCC or to the manufacterer to fix this at
the source before it gets worse.

Maybe "turn them in" to the FCC for a _finders fee_? :O)

-zero

Mark wrote:

Hi,
Then, shielding, choking, bypassing with caps come to mind. It's all by
trial and error. O'scope may come in handy.


Well that's my concern.
There are more and more of these kinds of units being installed
everyday.
We can't "home brew" a fix for all of them.
Someone needs to get to the FCC or to the manufacterer to fix this at
the source before it gets worse.

Mark

Yup,
EMI pollution!