1

I have a motor with this connection. I find it a bit strange that it has two terminals. I think it is a two-speed three-phase motor.

Which diagram from the paper is being used in the connection and how do I make the connections so it works at 700 RPM?

enter image description here

enter image description here

enter image description here

ocrdu
  • 8,705
  • 21
  • 30
  • 42
gsoap
  • 13
  • 4
  • 2
    Welcome to EE.SE! Two terminals? I see twelve of them. – winny Dec 19 '22 at 17:40
  • search for [Dahlander](https://en.m.wikipedia.org/wiki/Dahlander_pole_changing_motor) – greybeard Dec 19 '22 at 17:41
  • @winny thanks you! well you are right, i meant 2 blocks (or how they are called). Sorry for my english – gsoap Dec 19 '22 at 17:41
  • @greybeard i will, thank you! – gsoap Dec 19 '22 at 17:43
  • No worries! Are there any markings of the cables from the motor windings? Do they correspond to the X, Y and Z markings on the terminal block? – winny Dec 19 '22 at 17:45
  • @winny sadly no. This motor was burned and rewinded by a technician that didn't bother to do so. He only gave me the white paper if I wanted to change the connection. – gsoap Dec 19 '22 at 17:50

1 Answers1

3

It's a Dahlander, pole-changing, two-speed motor.

Here's the schematic.

enter image description here

Two terminal blocks have been provided to facilitate motor configuration for either 700 RPM or 1400 RPM.

enter image description here

enter image description here

A couple of contactors would be required in order to have the flexibility to select 700 RPM or 1400 RPM.

Conclusion

A study of the brake motor link, provided by the OP in his comment, indicates the following:

  1. Separate terminal blocks have been provided for the three phase brake and motor connections.

  2. The connection diagram is as shown below.

enter image description here

  1. The motor has been wired for 700 RPM.
vu2nan
  • 15,929
  • 1
  • 14
  • 42
  • 1
    (Any explanation for two blocks of 6 terminals instead of one?) – greybeard Dec 20 '22 at 04:51
  • @greybeard - Hi, Thank you for your response. The explanation has been incorporated in my answer. – vu2nan Dec 20 '22 at 06:53
  • @vu2nan thanks a lot! So the connection in the photo is the one for 700 rpm right?? Also from the research I have done since yesterday the second block seems to be a motor brake. I am not sure – gsoap Dec 20 '22 at 14:14
  • Anytime, gsoap! Both the terminal blocks are for configuring the motor to run at either 700 RPM or 1400 RPM. There are no additional terminals for a brake (no brake). Two terminals are free since the three lugs for X, Y & Z are connected to a single terminal. X, Y & Z being shorted together is an indication that the motor is configured for 1400 RPM. – vu2nan Dec 20 '22 at 16:10
  • 1
    @vu2nan I am getting close to understand this. So if I want 700 rpm should I put the top X, Y & Z in their seperate lugs and put L1, L2 & L3 from U, V & W on top of X, Y & Z or should I replace other wires as well? I am getting very confused on the principle of two terminal blocks.. Also please check this link I found for the brake https://www.mgmrestop.com/wp-content/uploads/2015/03/BAD-AC-brake.jpg – gsoap Dec 20 '22 at 17:24
  • Hi gsoap, It appears that the wiring diagrams (link provided by you above) do not refer to this motor. The wiring diagrams shown in the white paper given by the technician and the ones shown in my answer tally. The technician has wired the motor for 1400 RPM. You need to take his or another competent technician's help to wire it for 700 RPM. Your description of the wiring changes for 700 RPM are a bit confusing. – vu2nan Dec 21 '22 at 10:13
  • @vu2nan Thank you, I appreciate your help. – gsoap Dec 21 '22 at 19:27
  • @vu2nan I am sure this motor has a brake. I sent the link as a reference and not specifically for this motor but in general of how this company wires motors with AC breaks. If you could provide general bibliography of why it has two terminal blocks (since I only found Dahlander motors with only one terminal block) I would go with your answer. Anyway I ended up wiring a vfd to control the motor rpm to my liking. Nevertheless thank you a lot for your help, I appreciate it. – gsoap Dec 21 '22 at 19:33
  • You are most welcome, gsoap. Thank you for all the information, based on which my answer has undergone an edit. – vu2nan Dec 22 '22 at 06:23
  • @gsoap: `ended up wiring a VFD` how contemporary. Now Dahlander motors aren't usually EFF1/IE3 (mandatory in the EU for .75 kW up since 2021/7/1, if for non-controlled speed). – greybeard Dec 22 '22 at 06:33
  • @vu2nan now it all seems clear to me! thanks again for your time! – gsoap Dec 27 '22 at 17:28
  • @greybeard I don't know if it is the right thing to do for a dahlander motor but it works! – gsoap Dec 27 '22 at 17:29