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BS for Star Delta starters

grahamro

I have an old, very old 2 contactor Star/Delta starter an Auto Memota 254SD to be precise..............

I'm just enquiring if this starter still complies with any relevant British standards.

I started my electrical journey in 1967 and this starter predates this time by about 30 years!

All my experience of S/D starters since I started out has been on 3 contactor types. It's starting a similar aged 10hp Crompton Parkinson induction motor.

Quite interesting watching the run contactor kick in when changing over from Star to Delta, there are arc shields over the contacts, I understand why now.

Any help much appreciated............I first posted this over in the engineering discussions but got no replies, I'm hoping my fellow hands on associates can help out.

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    Oddly I replied last night and it is not showing. I'll type again, but this is necessarily terser due to time of day

    It looks like there may be a kick-off winding on each contactor in series with the main winding on its neighbour - if and only if the winding handed-ness is correctly captured in the drawing. If that really  is what it is is showing then the idea is to ensure break before make. (and to have something acting like a transformer secondary winding whose voltage   tells you the core has pulled in.) However there is also stuff happening with the auxilliary contacts on L2 B2 A1 that is not entirely clear, so there may also be a hard pull-in (short fat winding) soft hold (long thin winding) type arrangement changeover in there as well.  Again this is to ensure sharp switching.

    It is not really the clearest  diagram in that respect.


    Mike.

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  • 0

    Oddly I replied last night and it is not showing. I'll type again, but this is necessarily terser due to time of day

    It looks like there may be a kick-off winding on each contactor in series with the main winding on its neighbour - if and only if the winding handed-ness is correctly captured in the drawing. If that really  is what it is is showing then the idea is to ensure break before make. (and to have something acting like a transformer secondary winding whose voltage   tells you the core has pulled in.) However there is also stuff happening with the auxilliary contacts on L2 B2 A1 that is not entirely clear, so there may also be a hard pull-in (short fat winding) soft hold (long thin winding) type arrangement changeover in there as well.  Again this is to ensure sharp switching.

    It is not really the clearest  diagram in that respect.


    Mike.

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