2018-07-26 6:21 GMT+02:00 Paul Anderson via cctalk <[email protected]>:
> I can't find my IPB, but the maintenance manual shows there were both 50 > and 60 hz versions made. > > I think I've shipped them overseas, but never modified them. I did ship a > lot of RX02 drives overseas, and to properly convert them the pulleys, > belts, and wiring harness had to be swapped. We were always on the lookout > for parts. I still have a few different wiring harnesses around here > somewhere. > > BA11-K conversions were also common. I still have interesting stories and > parts about them. > > What gets me with the RK05 is how you can swap pulleys without swapping > belts. A few products had pulleys with two grooves, one for 50, the other > for 60. But you still needed a different belt. > You need to move the motor to a new position in the RK05. The drive is already prepared for all this. It is just the pulley, moving the motor and the 220VAC jumper that is needed. /Mattis > > Paul > > On Wed, Jul 25, 2018 at 10:32 PM, Tony Duell via cctalk < > [email protected]> wrote: > > > > There are, however, DEC products other than the RK05 which had > different > > > transformers for 50 Hz and 60 Hz. For example, the H771 power supply > used > > > in the RX01 and RX02. There were three H771 models, The H771A for > 90-132 > > > VAC 60 Hz, The H771C for 90-132 VAC 50 Hz, and the H771D for 180-264 > VAC > > 50 > > > Hz. The H771A uses a transformer rated for 60 Hz. The H771C and H771D > > both > > > use the same 50 Hz rated transformer, with different wiring. The H771C > > and > > > H771D also require one of two different wiring harnesses to cover the > > > entire mains voltage range, e.g., 90-120 VAC vs 100-132 VAC for the > > H771C, > > > or twice those voltages for the H771D. > > > > IIRC that's a ferroresonant transformer (with a capacitor to resonate one > > of the > > windings to a harmonic of the power line frequency), so it's not > > surprising it has > > to be changed for 50Hz or 60Hz input. > > > > -tony > > >
