star delta

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M107

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Morning boys & girls

Ever get into something you wish you hadn't :|

Well the existing starter is that old star delta hand cranked thing ( you may remember the pics I'll re post them tonight).

So the customer dropped off a brand spanking new Newlec 400v coil star delta starter.

The problem (one of them anyway) I have is the old compressor only has three conductors connected to the old starter, but the wiring diagram for the new star delta shows six conductors connected to the starter?

I admit I'm not over confident with setting up the star delta anyway (with respect to the thermal relay etc Blushing )

I'll give up trying to explain with just words & sort some pics out, of how I think it goes & post tonight.

Looking forward to some help mixed with the banter later then Pray

I must have had a mind f*** on the go when I said yes I'll take a look for you.....what a w***** :_|

 

Flying Scotsman

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Morning boys & girlsEver get into something you wish you hadn't :|

Well the existing starter is that old star delta hand cranked thing ( you may remember the pics I'll re post them tonight).

So the customer dropped off a brand spanking new Newlec 400v coil star delta starter.

The problem (one of them anyway) I have is the old compressor only has three conductors connected to the old starter, but the wiring diagram for the new star delta shows six conductors connected to the starter?

I admit I'm not over confident with setting up the star delta anyway (with respect to the thermal relay etc Blushing )

I'll give up trying to explain with just words & sort some pics out, of how I think it goes & post tonight.

Looking forward to some help mixed with the banter later then Pray

I must have had a mind f*** on the go when I said yes I'll take a look for you.....what a w***** :_|
YOU SAID IT :^O :^O:^O:^O:^O:^O NOT US :^O :^O:^O:^O:^O:_|

Only joking mate ive done it it the past then found ive not known much about something thats out of my depth. Im sure someone will be along shortly to advise you.

FS

have a Guiness Drink while your waiting :D

 

sparkyrj

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sounds like you may have an old manual rheostat starter there not a star delta. These only needed three connectons to the motor.you could probably install another three cables so that you can use the star delta starter. This website may help.http://www.wiringmanual.com it has wiring diagrams for the different types of starters. You may even be able to use some kind of soft starter instead, that would only need the three cores.

hope this helps.

 

Lee321

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maybe the "old starter" was similar to what we now call soft starts?

but as said for correct star delta starting you need all 6 cables from the motor windings

 

M107

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Sorry peeps been busy here are the pics of the old kit

Outside of the case

http://i83.photobucket.com/albums/j293/gazjothomas/DSC00049.jpg

The inside of case

http://i83.photobucket.com/albums/j293/gazjothomas/DSC00047.jpg

The current set up

http://i83.photobucket.com/albums/j293/gazjothomas/DSC00048-1.jpg

As I said only three conductors to the compressor, now I'm remembering back to college & I'm sure 6 were required (both ends of windings?), so it's hands up & I now acknowledge that industrial sparks are the greater ..... :) , as for the job I'm gonna give it a miss I think, got plenty on anyway in my own field HOUSE BASHING :^O

Anyway this has highlighted an area that I'd like to brush up on so be ready for some questions in the comming weeks.

Now its time for :z :z:z said zebadee

 

Lee321

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i'd say the motor has been replaced at some point too, possibly long ago

and was running just direct on line . i.e the star delta starter was configured to not complete the change from star to delta

 

benji

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that starter must be about 50yrs old ,you used to hold the handle down until speed built up in star then quickly move it up (and if it held in it was in delta )the cores look fairly small do you need star delta ,lets have a few shots of motor

benji

 

Pyro

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What's the background on the 3rd photo - the inside of the existing box?

There are 6 wires at the top of the box and 3 wires at the bottom of the box.

Curious, am I.

Pyro.

 
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You need to check the motor and see how many `ends out` there are in the terminal box. If the motor has been replaced, but with a 3 terminal version then you will be wasting your time with a star/delta starter. If the motor has 6 terminals i.e. `ends out` then it will be possible to run extra wiring from motor to starter and install the new star/delta starter (assuming that the overload rating matches the motor rating of course:)). Mind you, the six wires at the top of the starter could be interesting - they could be a looped feed from another starter.

 

benji

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the six cores at the top go to the motor the three at the bottom are the supply when you hold the handle down the starter puts a feed onto three of the cores and bridges the other three together ie. star when you push the handle up the starter opens the bridge and then it feeds all six cores ie. delta

yours benji (sure i've sent this before must be a bit of dementure creeping in )

 

M107

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the six cores at the top go to the motor the three at the bottom are the supply when you hold the handle down the starter puts a feed onto three of the cores and bridges the other three together ie. star when you push the handle up the starter opens the bridge and then it feeds all six cores ie. deltayours benji (sure i've sent this before must be a bit of dementure creeping in )
Nope the 3 at the bottom defo go to the motor.

The 6 entering from the top are off the 3phase cu on reverse side of wall.

 

sparkyrj

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What you have there is a rheostat starter.There are only three connections to the motor with these, and you start the motor with the handle in the position with the most resistance, and slowly move it to the other end as the motor gets going, this prevents high current at start up.I used to work at a department store in the 1980s and they had one for their compressor that ran the tube system for transferring money from the tills to the cash office.I had to start this up every morning, and if you were too fast with the handle it would trip out and you had to start again.Its probably from the days before star delta starters.

 

benji

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i dont think so ,a resistance starter would have to have a built in resistance bank you ai'nt got one there

yours benji

 

Mr Sworld

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the six cores at the top go to the motor the three at the bottom are the supply when you hold the handle down the starter puts a feed onto three of the cores and bridges the other three together ie. star when you push the handle up the starter opens the bridge and then it feeds all six cores ie. deltayours benji (sure i've sent this before must be a bit of dementure creeping in )
You're close!

The reason why there are six cores is because one set of three cores feeds the star side and the other three the delta side. When you turn it on it uses mechanical interlocks to energise the star side first and then as the lever is pusher further the delta side is then interlocked and the star side de-energised.

M107, you can rip out one set of wires and replace with a modern day S-D starter than only needs one input set.

 

Mr Sworld

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I'm reversing my previous answer.

Looking closely at this picture have you notice that the cover at the bottom of the starter has a Warning notice on it and it's upside down?

This would seem to be a protective cover for the live incoming terminals.

M107, could this of been installed upside down? :eek:

It would explain a lot and make sense of the wiring diagram here which does show 3 in-coming lives and two sets of three out-going for the star and delta wiring.

Benji, sorry for my previous, you are correct. :p

 

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