On 7 January 2016 at 18:10, John Kasunich <jmkasun...@fastmail.fm> wrote:
>> The manual states 5A / Phase @400V but I have rewired the motor for 240V. >> >> (Maybe I should try wiring it back to 440V?) > > You wrote "5A @ 400V", and then wrote "back to 440V". Is it 400 or 440? It depends on where you look. The lathe installation instructions say "440V 50Hz 3-phase" The Variator Unit section says: "5.0 A per phase FLC at 400V" > My understanding is that in EU and UK, dual voltage motors are 400/230. > That is a sqrt(3):1 ratio and it is done by reconnecting from wye to delta. > There are six leads in the terminal box. UK power is nominally 230V to harmonise with the EU, but is 230 +10% - 5% and is normally 240V. It was 240V when the lathe was made. https://www.tlc-direct.co.uk/Book/1.1.htm That also says that the spread of allowable UK 3-phase voltage is 376 to 440V. > Which one applies here? Was there a wiring diagram for the reconnection > or did you have to guess? How confident are you that the reconnection is > correct? There was no wiring diagram, so I guessed. Before https://picasaweb.google.com/108164504656404380542/Holbrook#6184070662873243538 with wires labelled A1, A2, B1, B2, C1, C2 After: https://picasaweb.google.com/108164504656404380542/Holbrook#6184102342306740594 > 5A * 400V * sqrt(3) = 3.46kVA, and 8.66A at 230V is the same. I left the clamp ammeter at work, but looking at the VFD display. Low speed / low ratio: 80rpm = 3.0 A Low speed / high ratio 500rpm = 6.0A High speed / low ratio 500rpm = 3.4A High speed 10 A = 2000rpm. > More questions: when does the trip happen? During acceleration, > or some time later after it has reached normal speed? If during > acceleration, does it happen right away (say less than 10% of > full speed)? Or later, at 50% speed or higher? It rather depends on how I operate the controls. I can start at low speed and slowly wind-up the variator and get about 1800 rpm. However, if I want to be able to start and stop without variator action then I have to leave the variator at the 1000 rpm setting. As the variator can not be adjusted without the spindle turning it is better not to have to be twiddling it before stopping to re-start. I have, in the course of discovering the last fact, made some interesting discoveries. In the 1000 rpm position at 100 Hz I can have 2000 rpm at 7A. If I stay at 50Hz and wind up the variator then the current rapidly rises. If adjust speed to 10A then it is about 2000 rpm, but then all of a sudden the current ramped up to 18A and the VFD tripped. This is strongly pointing to a mechanical problem with the Variator. Which I have been quoted £1600 to refurbish. > It looks like parameters 00-14 and 00-16 are acceleration times. > What do you have them set to? They were 7.5 and 10. > For experimentation > purposes don't hesitate to set them to 60 seconds or so, that > will let you watch the meters as it slowly accelerates and get > a better idea of what is going on. If a 60 second accel still > results in current of more than 8A we will need to dig deeper. This was interesting. In the highest gear the current ramps slowly up to 18A and a trip without the motor even moving. At a lower variator setting in high gear there is no motor movement until 5A, then it starts to slowly build to 2000rpm at 7A. Then a sudden increase to 18A and a trip. > To be honest, for something like this I strongly believe that > the very first step is to tell the drive everything you know about > the motor. The highest priority are parameters 01-00, 01-01, > and 02-01. Those are absolutely necessary. You probably > want "1", "230", and "8.66" respectively. Currently 1, 220 and 8.0. > If you had a nameplate it would give you 02-03. Keep 02-02 > zero since you don't know the proper value for 02-03. If you > can decouple the motor from all mechanical loads you could > run it up to 50Hz to determine 02-00, Otherwise, set 02-00 > to about 35-40% of 02-03, and keep 02-02 zero. I could put the 2-speed box in neutral and set the Variator to minimum speed, but the evidence really is pointing at the variator as the main load. The variator is noisy (it shouldn't be), can't be adjusted when the spindle is stopped and is difficult for a PC to control. It also might be broken. I was wondering whether to keep it, I think my mind is made up. -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
