Ferroresonant transformers and 3278
tmfdmike at gmail.com
Mon Dec 21 21:45:35 CST 2015
I do have a massive idler motor - as in it takes two people to even
think about lifting it - from my days in NY when I had to manufacture
a 3rd phase to make the S/3 and other items work... I wonder if I
could do anything using that as a starting point?
Three phase is no problem here... previous owner of house was a
woodworker and I have 3-phase 50Hz 400V straight to the workshop
already wired in :-)
Finagle's law says 90% of my 3-phase big iron was acquired in the USA
and expects 3-phase 60Hz 208V... :-(
On Tue, Dec 22, 2015 at 4:03 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.
> 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...
>> 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.
>>> 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...
>>>> '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.'
>> '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.'
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