31 Dec
2015
31 Dec
'15
3:05 a.m.
On 12/30/2015 11:45 PM, Mike Ross wrote:
Thanks for the thought... my main concern is the
System/3s and Henk
Stegeman - who has forgotten more than most of us will ever know about
S/3! - says that 60Hz S/3 on 50Hz power is a no-go. Different voltage,
fine - transformer can be restrapped. Different frequency... trouble!
And then there are rotary machines of course. I bet you half my disks
drives need the right frequency or a spindle pulley change.. and even
then *they* probably have ferroresonants in their power...
Mike
Order a boatload of 8kw honda generators? I think you could get 40 amps
out of them. Any reason the power has to be in phase?
I know for the mainframe power that might not be high enough, but on
smaller machines it would take care of the problem.
thanks
JIm
On Thu, Dec 31, 2015 at 6:37 PM, William Donzelli
<wdonzelli at gmail.com> wrote:
I bet you (or Mike, actually) could get it to
work by trial and error,
swapping in caps. The transformers (generally) are apparently pretty
forgiving - being off in frequency just results in lost efficiency,
maybe 10-15 percent lost at most. Not flames, anyway.
--
Will
On Thu, Dec 31, 2015 at 12:30 AM, Guy Sotomayor <ggs at shiresoft.com> wrote:
>
> On 12/30/15 9:29 PM, William Donzelli wrote:
>> Of course! Find the exception that proves the rule!
>
> ;-) However, it would've been nice if it were only necessary to change
> the capacitor!
>
> TTFN - Guy
>
>> --
>> Will
>>
>> On Thu, Dec 31, 2015 at 12:23 AM, Guy Sotomayor <ggs at shiresoft.com>
wrote:
>>>
>>> On 12/30/15 9:06 PM, William Donzelli wrote:
>>>> Sorry about digging up a slightly stale thread...
>>>>
>>>>> 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.
>>>> ...but straight from the horses mouth, most IBM ferroresonant
>>>> transformers will work at 50 or 60 Hz. The capacitor may need to be
>>>> swapped, depending on the equipment.
>>>>
>>>> I was hanging around some IBM old timers this evening, including the
>>>> Big Horse at Endicott.
>>>
>>> I just looked up the FE manual for the 3278 and it shows 5 different part
>>> numbers for the
>>> ferroresonant transformer (depending upon region) and only a single part
>>> number for the
>>> capacitor.
>>>
>>> TTFN - Guy
>