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OT A/C RFI

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K7TV

OT A/C RFI

Need to replace my A/C, and worried about getting an RFI generator.

A few years ago I saw some advice about taming a new unit, and maybe even
getting instructions from the manufacturer.

Things change all the time, and at this point I would like to hear from
anyone with fresh advice: Brands to consider with minimal emissions och
solid instructions for filtering them out, etc.

Please reply directly to me, or keep it short on the list.

Thanks in advance,

73,

Erik K7TV

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k4vd

Re: OT A/C RFI

The timing is perfect. Please keep it on the list or add me to your direct
replies. Maybe we can cut it short of the limit for OT subjects without
needing a reminder.

I have not had an AC since last summer and have also not had any noise
around the shack. Now it's just getting to hot to deal without central air
so I'm interviewing my second AC contractor on Thursday. I'd love to hear
some good ham advice on best practices for AC installations.

I was thinking at a minimum a good name brand (not a builders special, not
department store brand), good solid grounding, as far from the shack as
possible (not too possible here).

73,
Kev K4VD

On Tue, Jul 18, 2017 at 9:02 PM, Erik Basilier <[hidden email]> wrote:

> Need to replace my A/C, and worried about getting an RFI generator.
>
> A few years ago I saw some advice about taming a new unit, and maybe even
> getting instructions from the manufacturer.
>
> Things change all the time, and at this point I would like to hear from
> anyone with fresh advice: Brands to consider with minimal emissions och
> solid instructions for filtering them out, etc.
>
> Please reply directly to me, or keep it short on the list.
>
> Thanks in advance,
>
> 73,
>
> Erik K7TV
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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NK7Z

Re: OT A/C RFI

In reply to this post by K7TV

Write it into the contract that the unit will not generate RFI above
some level you are happy with, as received at your radio, using your
current antenna, across the entire spectrum your radio covers.

I did, and the installers then made sure it was RFI proof... I wrote it
into the contract in general terms that favored me, and left it up to me
to say yes or no as to if it were acceptable.

Bring it up first, remind them about it later, tell them it is a show
stopper if the unit generates RFI, put it in writing...

Make sure EVERYTHING is in writing. Be nice to them, but let them know
in no uncertain terms that RFI is not acceptable to you, and they will
be on the hook to correct it if RFI exists as a result of the new unit.

The vendors get really careful when you set things up that way...

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 07/18/2017 06:02 PM, Erik Basilier wrote:

NK7Z

Re: OT A/C RFI

In reply to this post by k4vd

When this goes off list please add me as well... Don't tell them what
to do, tell them you want no RFI. If you tell them what to do, and it
does not work, it is your issue... Make it their issue. See my
previous post.

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 07/18/2017 06:54 PM, Kevin der Kinderen wrote:

> The timing is perfect. Please keep it on the list or add me to your direct
> replies. Maybe we can cut it short of the limit for OT subjects without
> needing a reminder.
>
> I have not had an AC since last summer and have also not had any noise
> around the shack. Now it's just getting to hot to deal without central air
> so I'm interviewing my second AC contractor on Thursday. I'd love to hear
> some good ham advice on best practices for AC installations.
>
> I was thinking at a minimum a good name brand (not a builders special, not
> department store brand), good solid grounding, as far from the shack as
> possible (not too possible here).
>
> 73,
> Kev K4VD
>
>
>
> On Tue, Jul 18, 2017 at 9:02 PM, Erik Basilier <[hidden email]> wrote:
>
>> Need to replace my A/C, and worried about getting an RFI generator.
>>
>> A few years ago I saw some advice about taming a new unit, and maybe even
>> getting instructions from the manufacturer.
>>
>> Things change all the time, and at this point I would like to hear from
>> anyone with fresh advice: Brands to consider with minimal emissions och
>> solid instructions for filtering them out, etc.
>>
>> Please reply directly to me, or keep it short on the list.
>>
>> Thanks in advance,
>>
>> 73,
>>
>> Erik K7TV
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>>
> ______________________________________________________________
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Jim Brown-10

Re: OT A/C RFI

In reply to this post by K7TV

On 7/18/2017 6:02 PM, Erik Basilier wrote:
> Need to replace my A/C, and worried about getting an RFI generator.
>
> A few years ago I saw some advice about taming a new unit, and maybe even
> getting instructions from the manufacturer.

Dave Cole has given you excellent advice, and you should follow it
carefully. I'll add this additional caution. The "upgrade" in HVAC
systems (heating, ventilating, air conditioning) is a variable speed
motor. The controllers for these motors are notorious for bad RFI, so by
all means, do NOT buy that option.

73, Jim K9YC

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NK7Z

Re: OT A/C RFI

Thanks Jim!

I passed on the variable speed fan option as a result of the vendor
telling me I should skip it to avoid possible RFI.

He also said it made little difference in performance... BTW I have no
detectable RFI from my system.

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 07/18/2017 08:40 PM, Jim Brown wrote:

> On 7/18/2017 6:02 PM, Erik Basilier wrote:
>> Need to replace my A/C, and worried about getting an RFI generator.
>>
>> A few years ago I saw some advice about taming a new unit, and maybe even
>> getting instructions from the manufacturer.
>
> Dave Cole has given you excellent advice, and you should follow it
> carefully. I'll add this additional caution. The "upgrade" in HVAC
> systems (heating, ventilating, air conditioning) is a variable speed
> motor. The controllers for these motors are notorious for bad RFI, so by
> all means, do NOT buy that option.
>
> 73, Jim K9YC
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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Clay Autery-2

Re: OT A/C RFI

In reply to this post by NK7Z

Please include me in a list of folks who wants to follow/contribute to
this topic if/when it goes off-list.

I am shopping for HVAC right now...

______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/18/2017 9:00 PM, Dave Cole wrote:
> When this goes off list please add me as well... Don't tell them what
> to do, tell them you want no RFI. If you tell them what to do, and it
> does not work, it is your issue... Make it their issue. See my
> previous post.
>
> 73s and thanks,
> Dave
> NK7Z
> http://www.nk7z.net
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Clay Autery-2

Re: OT A/C RFI

In reply to this post by Jim Brown-10

Hmmmm.... Jim... I have a variable speed down-hole pump on my water
well... reckon that could cause RFI via the AC wiring?
The down-hole pump is 220VDC on dedicated circuit, and shack is on a
separate dedicated circuit from same service with separate sub-panel.

______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/18/2017 10:40 PM, Jim Brown wrote:

NK7Z

Re: OT A/C RFI

Clay,
Given that the pump is far, far underground, as is most of the wiring, I
would expect it to be a trivial matter to filter the AC line, which
should be the only thing radiating... Was that the case for you?

73s and thanks,
Dave
NK7Z
http://www.nk7z.net

On 07/19/2017 07:52 AM, Clay Autery wrote:

> Hmmmm.... Jim... I have a variable speed down-hole pump on my water
> well... reckon that could cause RFI via the AC wiring?
> The down-hole pump is 220VDC on dedicated circuit, and shack is on a
> separate dedicated circuit from same service with separate sub-panel.
>
> ______________________
> Clay Autery, KY5G
> MONTAC Enterprises
> (318) 518-1389
>
> On 7/18/2017 10:40 PM, Jim Brown wrote:
>> On 7/18/2017 6:02 PM, Erik Basilier wrote:
>>> Need to replace my A/C, and worried about getting an RFI generator.
>>>
>>> A few years ago I saw some advice about taming a new unit, and maybe
>>> even
>>> getting instructions from the manufacturer.
>>
>> Dave Cole has given you excellent advice, and you should follow it
>> carefully. I'll add this additional caution. The "upgrade" in HVAC
>> systems (heating, ventilating, air conditioning) is a variable speed
>> motor. The controllers for these motors are notorious for bad RFI, so
>> by all means, do NOT buy that option.
>>
>> 73, Jim K9YC
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Bob McGraw - K4TAX

Re: OT A/C RFI

In reply to this post by Clay Autery-2

There's basically two types of RFI.

Conducted --- Being noise/RFI traveling through the wiring thus via
direct connection. Conducted RFI can be attenuated to satisfactory
levels by including a power line filter in the system {preferably at the
source}. The filter suppresses conducted noise leaving the unit,
reducing RFI to acceptable levels. It also helps to lower the
susceptibility of the equipment to incoming power line noise that can
affect its performance

Radiated --- Being noise/RFI via the wiring into the air, i.e.
transmitted. Separation of power and antenna physically is often an
improvement. Radiated RFI is usually controlled by providing proper
shielding in the enclosure of the equipment.

Regarding separate circuits, in most all cases each circuit terminates
into the service panel to which all are then common. The advantage I've
seen with separate circuits is in the distribution of neutral current.
A large unbalance in load between L1 and L2 results in a differential
neutral current. In this case, the IR value will cause the neutral to
be above earth/ground.

Often, figuring out which type and source is the challenge.

73
Bob, K4TAX

On 7/19/2017 9:52 AM, Clay Autery wrote:

Chuck - AE4CW

Re: OT A/C RFI

In reply to this post by Clay Autery-2

Variable speed drives on HVAC units are indeed prone to RFI generation. Five years ago I ordered a second TRANE HVAC for my home...identical model to the first EXCEPT the VDS was 3/4HP on the first and 1HP on the second. The first TRANE unit was and is dead quiet...no VSD interference visible on a very sensitive panadapter from 500KHz to 54MHz. The second unit turned out to be a prodigious RFI producer. As the installer and TRANE were of no help whatsoever, I contacted the company and engineer who designed the motors (who also happened to be a ham), and here is what I learned:
1) the 3/4HP motor is known to be quiet.
2) the 1HP motor is problematic and RFI is difficult to control.
3) after installing some manufacturer provided filters and personally supplied chokes and capacitors on the 1HP motor, the INSIDE HVAC unit is now quiet. NOTE: Every wire that leaves the enclosure must be filtered.
4) HOWEVER, there was ANOTHER RFI generator in the system. It turned out to be the cooling fan motor on the OUTSIDE compressor/condenser unit. This motor was wired to run at a fixed speed and was chosen by TRANE as it is slightly more efficient than the tradition induction motor.

So, yes, choose VSD's for your HVAC system with great caution. I personally like the variable air flow and increased efficiency, but they can come at a substantial cost in RFI. While turning the beam around the neighborhood I can easily see multiple VSD dive noise signatures which are usually a burst of very closely spaced carriers (a few hertz apart) spaced about 18KHz apart.
---
Chuck, AE4CW

-----Original Message-----
From: Clay Autery [mailto:[hidden email]]
Sent: Wednesday, July 19, 2017 10:53:AM
To: [hidden email]
Subject: Re: [Elecraft] OT A/C RFI

Hmmmm.... Jim... I have a variable speed down-hole pump on my water well... reckon that could cause RFI via the AC wiring?
The down-hole pump is 220VDC on dedicated circuit, and shack is on a separate dedicated circuit from same service with separate sub-panel.

______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/18/2017 10:40 PM, Jim Brown wrote:

---
Chuck, AE4CW

Clay Autery-2

Re: OT A/C RFI

In reply to this post by NK7Z

Frankly, I've never checked to see if the down-hole pump is an RFI
source... Only use the well when I am outside for the most part...
That's why I solicited Jim's opinion of the case.

I'll have to run a purposely test.

I would think I could filter at/near where the AC lines go in/out of the
hole (outside, and put in a metal enclosure?) And when I finally finish
the pump control/distribution manifold in the back yard, the AC lines
will be over-sized, twisted pair, and in grounded conduit.
Will do whatever is required to keep things quiet. My quiet zone is
slowly growing. :)

73,

______________________
Clay Autery, KY5G
MONTAC Enterprises
(318) 518-1389

On 7/19/2017 9:55 AM, Dave Cole wrote:

> Clay,
> Given that the pump is far, far underground, as is most of the wiring,
> I would expect it to be a trivial matter to filter the AC line, which
> should be the only thing radiating... Was that the case for you?
>
> 73s and thanks,
> Dave
> NK7Z
> http://www.nk7z.net
>
> On 07/19/2017 07:52 AM, Clay Autery wrote:
>> Hmmmm.... Jim... I have a variable speed down-hole pump on my water
>> well... reckon that could cause RFI via the AC wiring?
>> The down-hole pump is 220VDC on dedicated circuit, and shack is on a
>> separate dedicated circuit from same service with separate sub-panel.
>>
>> ______________________
>> Clay Autery, KY5G
>> MONTAC Enterprises
>> (318) 518-1389
>>
>> On 7/18/2017 10:40 PM, Jim Brown wrote:
>>> On 7/18/2017 6:02 PM, Erik Basilier wrote:
>>>> Need to replace my A/C, and worried about getting an RFI generator.
>>>>
>>>> A few years ago I saw some advice about taming a new unit, and maybe
>>>> even
>>>> getting instructions from the manufacturer.
>>>
>>> Dave Cole has given you excellent advice, and you should follow it
>>> carefully. I'll add this additional caution. The "upgrade" in HVAC
>>> systems (heating, ventilating, air conditioning) is a variable speed
>>> motor. The controllers for these motors are notorious for bad RFI, so
>>> by all means, do NOT buy that option.
>>>
>>> 73, Jim K9YC
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to [hidden email]
>>
> ______________________________________________________________
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Jim Brown-10

Re: OT A/C RFI

In reply to this post by Bob McGraw - K4TAX

This is gross over-simplification, but it is, sadly, the thinking of the
EMC community and the regulations on EMC.

I've written extensively on this, so won't repeat it here. Here's the
most recent.

http://k9yc.com/KillingReceiveNoise.pdf

And, of course, k9yc.com/RFI-Ham.pdf

VERY little RFI is conducted INTO equipment via the power line. Most RF
trash is conducted out of equipment by "the Pin One Problem" as a common
mode current on cable shields and the power system "green wire." it is
then radiated by that wiring, and ends up on our antennas like any other
radiated signal. This is the mechanism for radiation from CATV systems,
power systems, and nearly all electronics.

RF trash is also radiated by wiring internal to equipment as a result of
poor circuit layout and poor shielding. Both conditions must be present
-- it's entirely practical to build unshielded equipment with no
radiated trash using good circuit layout and construction. This
mechanism is often important with "big" equipment like HVAC systems and
solar systems.

73, Jim K9YC

On 7/19/2017 8:17 AM, Bob McGraw K4TAX wrote:

> There's basically two types of RFI.
>
> Conducted --- Being noise/RFI traveling through the wiring thus via
> direct connection. Conducted RFI can be attenuated to satisfactory
> levels by including a power line filter in the system {preferably at
> the source}. The filter suppresses conducted noise leaving the unit,
> reducing RFI to acceptable levels. It also helps to lower the
> susceptibility of the equipment to incoming power line noise that can
> affect its performance
>
> Radiated --- Being noise/RFI via the wiring into the air, i.e.
> transmitted. Separation of power and antenna physically is often an
> improvement. Radiated RFI is usually controlled by providing proper
> shielding in the enclosure of the equipment.
>
> Regarding separate circuits, in most all cases each circuit terminates
> into the service panel to which all are then common. The advantage
> I've seen with separate circuits is in the distribution of neutral
> current. A large unbalance in load between L1 and L2 results in a
> differential neutral current. In this case, the IR value will cause
> the neutral to be above earth/ground.
>
> Often, figuring out which type and source is the challenge.
>
> 73
> Bob, K4TAX
>
> On 7/19/2017 9:52 AM, Clay Autery wrote:
>> Hmmmm.... Jim... I have a variable speed down-hole pump on my water
>> well... reckon that could cause RFI via the AC wiring?
>> The down-hole pump is 220VDC on dedicated circuit, and shack is on a
>> separate dedicated circuit from same service with separate sub-panel.
>>
>> ______________________
>> Clay Autery, KY5G
>> MONTAC Enterprises
>> (318) 518-1389
>>
>>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Jim Brown-10

Re: OT A/C RFI

In reply to this post by Clay Autery-2

On 7/19/2017 7:52 AM, Clay Autery wrote:
> Hmmmm.... Jim... I have a variable speed down-hole pump on my water
> well... reckon that could cause RFI via the AC wiring?
> The down-hole pump is 220VDC on dedicated circuit, and shack is on a
> separate dedicated circuit from same service with separate sub-panel.

This is a complex question with no simple answer. Current flows in
loops, the loops produce magnetic fields which couple into other loops,
and the current also produces radiation. Radiation from the parts of the
loop that are under ground are certainly less than if they were above
ground. Those currents also produce IR drops.

Another mechanism that is often overlooked is leakage current on the
"green wire" as a result of capacitive coupling from the phase (hot)
conductor(s). This creates potential differences for that trash between
one equipment chassis and another. This is most often an issue at
baseband (harmonics of 50/60 Hz) but could also be a factor at RF.

73, Jim K9YC

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k6dgw

Re: OT A/C RFI

In reply to this post by Clay Autery-2

We had a well for 38 years, went through three 4 HP down-hole pumps, and
I never observed any RFI from it or the control/capacitor box at the
well head. The 240 V service to the entrance was buried. The pump ran
a lot when the irrigation system was on [making Pacific Gas & Electric
very happy [:-( ]. Our neighbor's A/C, about 200 ft from my tower was
something else again.

73,

Fred ("Skip") K6DGW
Sparks NV USA
Washoe County DM09dn

On 7/19/2017 9:02 AM, Clay Autery wrote:

> Frankly, I've never checked to see if the down-hole pump is an RFI
> source... Only use the well when I am outside for the most part...
> That's why I solicited Jim's opinion of the case.
>
> I'll have to run a purposely test.
>
> I would think I could filter at/near where the AC lines go in/out of the
> hole (outside, and put in a metal enclosure?) And when I finally finish
> the pump control/distribution manifold in the back yard, the AC lines
> will be over-sized, twisted pair, and in grounded conduit.
> Will do whatever is required to keep things quiet. My quiet zone is
> slowly growing. :)
>
> 73,
>
> ______________________
> Clay Autery, KY5G
> MONTAC Enterprises
> (318) 518-1389
>

John K9UWA-2

Re: OT A/C RFI

In reply to this post by NK7Z

Terry Schieler-2

FW: OT A/C RFI

In reply to this post by K7TV

More interest here than I expected on this, so I've decided to post my
direct response to Erik here as well.

Terry, WØFM

Hi Erik,

I just replaced my two 20 year old Lennox units with 4.0 Ton and 3.5 Ton
Trane units. Before the installers left I asked for a chance to check the
radios in the shack for RFI. The AC compressors are outside the basement
shack wall and the coils are inside about ten feet from the radios and feed
lines. Attic antennas all around for the moment. No detectable noise on
the new Trane units. And for what it's worth, the Lennox units (same size)
were also RFI free for 20 years. Good luck with your project and stay cool!

73,

Terry, WØFM

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W5RDW

Re: OT A/C RFI

In reply to this post by K7TV

I had this stored on my computer. Good reading on this subject.

http://www.arrl.org/forum/topics/view/46

Roger W5RDW

Eric Swartz - WA6HHQ

Re: OT A/C RFI

Administrator

Hi Everyone,

In the interest of reducing email overload for our readers, it is time to close
this thread as we are over the OT posting limit of 5 to10 at most.

Plesse self moderate in the future.

73,
Eric
Mooderator etc.
/elecraft.com/

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