Looking for an IBM 3803

[Chuck Guzis]

As long as you don't need the full blower capacity, you can probably do
the 3-phase-to-single-phase trick by using a capacitor from the third
lead to either (which one will determine rotation direction) of the two
other leads and feeding those leads with single-phase.   It's done very
often here with 3-phase shop equipment acquired by residential
hobbyists.  For motors, it's not critical, but it's not something that
you'd want to do for electronics--the phase distortion rules that out.

--Chuck




On 9/7/21 11:31 PM, Curious Marc wrote:
> Yes, we are hoping that we can power the  blower with 3 phase and the
> rest directly from the 240V electric car circuit… Not sure if that can
> be rewired for that.
> Marc
> 
>> On Sep 6, 2021, at 6:50 AM, Patrick Finnegan <pat at vax11.net> wrote:
>>
>> 
>> On Mon, Sep 6, 2021, 06:36 Curious Marc via cctalk
>> <cctalk at classiccmp.org <mailto:cctalk at classiccmp.org>> wrote:
>>
>>     I got both the 3420s and the 3808 from Sellam. On the restoration
>>     docket, now with a better chance thanks to the ALDs which I
>>     recently got from Gabriel himself. I scanned my 3420 ALDs and gave
>>     them to Gabriel in return. Biggest annoyance, besides humongous
>>     size and weight, is the amount of 3 phase power required.
>>
>>
>> From what I remember, the only thing that requires 3 phase in the
>> whole system is the blower motor in the 3420 drives. The rest are
>> powered off of single phase 200-240VAC.
>>
>> The large 3 phase input on it 3803 is likely overkill for even a
>> controller and full string of 8 drives. It's easier to oversize things
>> and have a 3x safety margin, then deal with running close to the
>> limits and risk any problems from poorly installed site wiring.
>>
>> Pat
>>
>>


-- 
--Chuck

Sent from my digital computer