Ferroresonant transformers and 3278

[drlegendre .]

For those of use who might have a broad, but more generic technical
knowledge - could you please explain exactly what a "3278" is?

Sincere query.. as the goog turns up nothing meaningful..

On Mon, Dec 21, 2015 at 9:03 PM, William Donzelli <wdonzelli at gmail.com>
wrote:

> If you can get a rotary one, those are really nice - just wasteful and
> loud. With proper maintenance they last forever, can take a beating,
> and do not give waveshape issues that cheap solid state units can
> have. And, maybe most importantly, you can make one yourself.
>
> But considering the mix of 50 and 60 Hz stuff you likely have by now
> (that is what you get for moving!), spending some decent money on a
> real VFD might be worth it. I might think a cheap VFD may give
> ferroresonant iron fits with all those extra harmonics.
>
> --
> Will
>
> On Mon, Dec 21, 2015 at 9:48 PM, Mike Ross <tmfdmike at gmail.com> wrote:
> > Any recommendations for what type? Are solid-state devices up to the
> > job these days? I still remember rotary converters...
> >
> > Mike
> >
> > On Tue, Dec 22, 2015 at 3:45 PM, William Donzelli <wdonzelli at gmail.com>
> wrote:
> >> In the long term, you should probably break down and get a good size
> >> frequency converter.
> >>
> >> --
> >> Will
> >>
> >> On Mon, Dec 21, 2015 at 9:33 PM, Mike Ross <tmfdmike at gmail.com> wrote:
> >>> I recently blew up a 3278... it worked ok for a few hours then started
> >>> blowing fuses.
> >>>
> >>> I haven't done any troubleshooting yet but checking the manuals on
> >>> Bitsavers tells me my US 3278s have ferroresonant transformers
> >>> specified as 120V 60Hz only. This can be expected to cause problems
> >>> with 120V 50Hz here in NZ from my knowledge of how ferroresonant
> >>> transformers work; I'll get excessive magnetic currents - overheating
> >>> - all kinds of nasties. I can wind the voltage down a bit and run them
> >>> at 90-100V but that doesn't help much.
> >>>
> >>> 1. Does anyone in a 50Hz country have any dead/spare 3278s and/or
> >>> transformers for them? The IBM part number for the 50Hz 220V are
> >>> 8715343 or 4119686.
> >>>
> >>> 2. I have other equipment where this will be an issue and not so
> >>> easily solved. Does anyone have any experience in or recommendations
> >>> for frequency conversion equipment? My System/3s for instance all use
> >>> 60Hz ferroresonants operating off 208V 3-phase - now voltage can
> >>> probably be retapped or easily converted but I still need to make a
> >>> lot of 60Hz to run them...
> >>>
> >>> Thanks
> >>>
> >>> Mike
> >>>
> >>> http://www.corestore.org
> >>> 'No greater love hath a man than he lay down his life for his brother.
> >>> Not for millions, not for glory, not for fame.
> >>> For one person, in the dark, where no one will ever know or see.'
> >
> >
> >
> > --
> >
> > http://www.corestore.org
> > 'No greater love hath a man than he lay down his life for his brother.
> > Not for millions, not for glory, not for fame.
> > For one person, in the dark, where no one will ever know or see.'
>