Top quality Pentair VS pool pumps generate huge RFI. Not just cheap Chinese. We
have two at VP5M. The only way to bring it down to acceptable levels is the
“brute force” line filter as close as possible to the pump. We use Schaffner
filters in the amp rating of the motor. Mouser sells them about $40 each
depending on amperage.
Let your installer buy and install if they will. You’ll be amazed at the
reduction in RFI if properly installed and grounded. You’ll also be amazed at
how much electricity well programmed VS pumps save. That’s critical for us with
island power at $.45/KwH!!
73,
Jim K4QPL VP5M
Sent from my iPhone
> On Jun 25, 2020, at 9:50 PM, Jim Brown <jim@audiosystemsgroup.com> wrote:
>
>> On 6/25/2020 5:18 PM, Jim McCook wrote:
>> No doubt it's a DC motor with a crummy Chinese switching power supply.
>
> Or a variable speed controller for the motor. There's an app note on my
> website about building contest scores by killing RX noise. It ran several
> years ago in NCJ. k9yc.com
>
> The first thing I would do is insist that the contractor and/mfr fix it. If
> you choose to try to fix it yourself, I'd start by winding 4-5 turns of every
> wire/cable connected to it through a #31 clamp-on. This means on the AC line
> side and on the motor side. And any control lines. These cables are
> transmitting antennas for the noise.
>
> Also, make certain that the path for current to that motor is a transmission
> line -- in other words, forward and return current flow in very close
> proximity, which confines the field to a very narrow region between the
> wires. Minimum, "zip cord;" twisted pair is 30 dB better.
>
> Also, I would be VERY, VERY cautious about working on this -- electrical
> safety can be a major factor. Several decades ago, a professional colleague
> was called in as an expert witness in a case where a preacher was
> electrocuted in the church's baptismal font while holding a microphone for
> the church's sound system (this was before the widespread use of wireless
> mics), and SOMETHING was not wired in conformance to electrical safety codes
> (the font or the sound system).
>
> 73, Jim K9YC
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