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Re: Ferrite ID

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On 9/25/26 16:58, David Lesher wrote:
> Rheem tankless water heaters, fed with dual 40A 240V circuits,
> are driving all the Leviton and other brand dimmers berserk.
> The lighting all dims and flickers beserkly. The Rheem has a
> sharp spike at the peaks of the positive and negative cycles;
> that is the cause.
> 
> The cure is some ferrite chokes on the power feeds. But fields
> class was Many Decades ago. I'm trying to decide if I want ones
> with an ID that just accepts the #8 stranded, or it doesn't
> matter that much if it's a loose fit.
> 
> Thoughts?
> 
> 
> 

First, need to define the rise time and shape of the spike,
to work out how much inductance is needed to filter it, along
with any caps at the supply side, for low pass filtering. You
could also try separating the feed to the heater, from
everything else, to reduce voltage drop effects. 40 amps is
pretty high current for a domestic setup, though electric
showers often match that, or more.

Sounds like a poor quality emc side of the design though.

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Ferrite ID David Lesher <wb8foz@panix.com> - 2026-09-25 15:58 +0000
  Re: Ferrite ID John R Walliker <jrwalliker@gmail.com> - 2026-09-25 17:02 +0100
  Re: Ferrite ID Bill Sloman <bill.sloman@ieee.org> - 2026-09-26 02:55 +1000
  Re: Ferrite ID john larkin <jl@htigct.com> - 2026-09-25 17:13 -0700
    Re: Ferrite ID Bill Sloman <bill.sloman@ieee.org> - 2026-09-26 16:39 +1000
      Re: Ferrite ID john larkin <jl@glen--canyon.com> - 2026-09-26 09:10 -0700
        Re: Ferrite ID Bill Sloman <bill.sloman@ieee.org> - 2026-09-27 16:32 +1000
          Re: Ferrite ID Brian Gregory <void-invalid-dead-dontuse@email.invalid> - 2026-09-28 23:30 +0100
            Re: Ferrite ID someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-09-29 19:15 +0000
              Re: Ferrite ID Bill Sloman <bill.sloman@ieee.org> - 2026-09-30 17:24 +1000
                Re: Ferrite ID john larkin <jl@glen--canyon.com> - 2026-09-30 07:50 -0700
                Re: Ferrite ID someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-09-30 20:00 +0000
        Re: Ferrite ID Bill Sloman <bill.sloman@ieee.org> - 2026-09-27 16:34 +1000
        Re: Ferrite ID someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-09-28 16:30 +0000
      Re: Ferrite ID someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-09-28 16:30 +0000
    Re: Ferrite ID someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-09-28 16:30 +0000
  Re: Ferrite ID Ian <devnul@blackhole.com> - 2026-09-26 11:57 +0100
    Re: Ferrite ID Bill Sloman <bill.sloman@ieee.org> - 2026-09-29 00:42 +1000
      Re: Ferrite ID Martin Rid <martin_riddle@verison.net> - 2026-09-28 11:04 -0400
        Re: Ferrite ID someone <2a59d59e3809f827ce709d3815e3950eef4a6a93af5557a93a7fdfba71460843@example.com> - 2026-10-01 04:15 +0000
      Re: Ferrite ID Ian <devnul@blackhole.com> - 2026-09-30 17:47 +0100

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