Ferroresonant transformers and 3278

[William Donzelli]

Another thought - with scrap transformer prices in a crapper right
now. you might also be able to pick up a really beefy isolation
transformer for spare change, in order to clean up a VFD. Generally,
normal industrial grade 50 Hz transformers will not care too much if
you use them at 60 Hz.

--
Will

On Mon, Dec 21, 2015 at 10:45 PM, Mike Ross <tmfdmike at gmail.com> wrote:
> Hmmmm.
>
> 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... :-(
>
> Mike
>
> 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.
>>
>> --
>> 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.'