----- Original Message -----
From: "Richard" <2@mail.vcnet.com>
To: "Jeff Weinberg W8CQ" <harbachelectronics@tds.net>; " AMPS"
<amps@contesting.com>
Sent: Saturday, June 08, 2002 6:32 AM
Subject: Re: [Amps] Strange Problerm
>
>
> >Hi Amps Readers,
> >
> >I will chime in here because I am the one who made the comment. What I
> >meant by the term "wild leg" is that one leg of the 240VAC mains may be
> >unbalanced with respect to the other leg (or neutral) in a single-phase
> >typical residential set-up..
>
> It matters not whether the legs are balanced with tespect to neutral
> because the 240V primary is not connected to the neutral wire. Mr. Rauch
> was right.
Also in the case 237 V AC is made with one leg of a 380V 3 phase and the
neutral (very common here in europe) the transformer windings are isolated
to each other and coupled magnetically.
73,
Mauri I4JMY
> >I know the term "wild leg" is normally used when talking about 3-phase
mains
> >where one of the legs fluctuates in voltage based on phase angle.
> >
> >I used the terms interchangeably in the conversation, but should have
been
> >more specific.
> >
> >As far as blowing one side of the capacitor bank, something must be
causing
> >a large DC voltage rise. I doubt it is AC killing the caps from the
SB-220
> >(if he has one of my FB-220 filter packs installed) because they are
> >protected with diodes across each cap to protect from AC getting into the
> >caps.
>
> agreed
> >
> >If the problem is evident in two different amps running from the same
house
> >circuit, a problem with the incoming mains is probably indicated. What
the
> >problem is, I don't know.
> >
> One, open V-equalizer-resistor would cause one cap to fail/short and this
> would dominos-fail the remaining caps in that string.
>
> >As far as a builder, yes, I am an experienced builder. As for a complete
> >Ph.D. level of theory, I don't have it and don't proclaim to.
> >
> >Tom or Rich, if you guys have an idea as to why this could occur, please
let
> >me and the list know. It sure does sound like something causing DC
voltage
> >over and far above the ratings of the caps in the side of the filter bank
> >that keeps blowing.
> >
> >Regards,
> >Jeff Weinberg W8CQ
> >Harbach Electronics
> >(317) 892-2641
> >harbachelectronics@tds.net
> >http://www.harbachelectronics.com
> >---------------------------------------------------------
> >
> >----- Original Message -----
> >From: "2" <2@vc.net>
> >To: "Tom Rauch" <W8JI@contesting.com>; " AMPS" <amps@contesting.com>;
> ><w5asp@earthlink.net>; <rauch@contesting.com>
> >Sent: Friday, June 07, 2002 8:41 AM
> >Subject: Re: [Amps] Strange Problerm
> >
> >
> >>
> >>
> >> >> Twice within the past six months we have had amplifiers fail due to
> >> >> the loss of all of the power supply filter capacitors in one "bank"
of
> >> >> the supply. Both amplifiers (an Alpha 76 and a SB-220) were being
run
> >> >> on 240 V AC. In both cases the filter capacitors were "relatively"
> >> >> new.
> >> >
> >> >...
> >> >> However, a recent comment by an experienced HV power supply builder,
> >> >> has brought up the subject of a possible "wild leg" in the 240 V AC
> >> >> line to which the amps were attached. According to this suggestion,
a
> >> >> large transient VOLTAGE swing on one leg of the 240 V mains put an
> >> >
> >> >Bad answer. He might be a good builder, but regretfully he must not
> >> >fully understand how supplies and power mains work.
> >> >.
> >> Amen, Mr. Rauch.
> >>
> >> - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
> >> www.vcnet.com/measures.
> >> end
> >>
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >>
> >
> >
> >
>
>
> - R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
> www.vcnet.com/measures.
> end
>
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