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M107

Billy-the-Kid
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Evening peeps,

Well I've been to look at a job for a mate & the star delta starter handle doesnt stay latched on the run position.

This is the starter

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

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

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

The starter operates a compressor motor

7.5watt

380-420v

14.5amp

As you may be aware I'm more the domestic side of sparking (haven't touched starters since college) so any tips on replacements?

 
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Two thoughts occur m8:

1. can you attack the existing unit mechanically, in order to re-introduce the latching mechanism?

2. Replace it with the newer changeover switches, which include a time delay, allowing the motor to start, then after a few seconds, swaps state.

I`m sure I`ve got info on one around here, if you want me to digi it out?

HTH

KME

 

M107

Billy-the-Kid
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Two thoughts occur m8:1. can you attack the existing unit mechanically, in order to re-introduce the latching mechanism?

2. Replace it with the newer changeover switches, which include a time delay, allowing the motor to start, then after a few seconds, swaps state.

I`m sure I`ve got info on one around here, if you want me to digi it out?

HTH

KME
Cheers KME any info would be a help.

I think you could be right SL a right antiquicated bit of kit it is:D the label does say 1957 & the workshop gaffer said he remembers it going in to replace the old unit sometime in late 1960's when he started there as an apprentice.

I was only there to take a look at extending socket circuits, all in conduit nice little job then he plops this on me.

Its in a metal workshop by the way & not being one to turn down a challenge......well you know how it goes :^O

 
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Cheers KME any info would be a help.I think you could be right SL a right antiquicated bit of kit it is:D the label does say 1957 & the workshop gaffer said he remembers it going in to replace the old unit sometime in late 1960's when he started there as an apprentice.

I was only there to take a look at extending socket circuits, all in conduit nice little job then he plops this on me.

Its in a metal workshop by the way & not being one to turn down a challenge......well you know how it goes :^O
So the workshop gaffa is only a young-un then... :D

better put a tick on the Lego brick pile for him! ?:|

I wish you well with your challenge... ;)

Mr M107 you are obviously a braver man the I... :)

But then you have got that big gun & a ruddy tank.. :eek:

I only have me little trailer:( (but it does have a sticker! :^O )

oh well..

Trailer boy says good morning.

and good bye..

time go see them nice customers me thinks? :D

 

Mr Sworld

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MEM has a nice little guide to selection of starters here.

Personally I'd replace rather than repair. Starters don't cost too much nowadays and soft-starts can give energy savings.

 

ally83

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Hello M107, I encountered a startedr from that era last year on a pillar drill my boss thought would be a "good investment" although it wasnt a soft start. I changed it out for Brook Crompton starter.

The good investment has since been scrapped.

 

M107

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Cheers ally83

Yes I've been looking at the brook crompton starters & that may well be the route I go.

 

M107

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Just thought I'd update you on this one.

Well I did pass the job over & another local company were brought in to change the starter (I do know the company & they are locally well known)

Anyway I got a call from the customer wanting some other work doing, I visited the factory to quote & was told what had unfolded with the starter.

The spark turned up changed the starter (took him 4-5 hours) ocpd (bs88's)kept tripping when he started the compressor, eventually he showed the factory boss that the starter works & compressor was running & the sparks departs.

Next day they start up the compressor it runs for 5 mins max & BANG goes the motor lots of smoke from compressor / galv conduit run between starter & cu & cu itself, floor supervisor dumps the chamber isolator shutting down the place

My mate happened to be there doing the em lighting so took a look for them.... oh dear oh dear oh dear...he found in the cu the fuse carriers had been bridged with bits of stripped t/e conductor, one way of curing the constant tripping ocpd :eek: the circuit conductors melted in the conduit & in the cu.

The factory boss called the electrical company to ask why's and where fores & was told no it's your compressor thats caused the fault the spark sent to the factory was their top bloke & knows his stuff. So the factory gaffer called in a specialist motor firm (cant remember the name) who said the motor is buggered & the reason is down to the top electricain single phasing (was the term used I think) the windings.........basically he'd wired it wrong......................soooooooooooo glad I passed it over. The motor company re-wired the circuit & replaced the compressor/motor.

The factory boss has refused payment & It's now in the hands of a lawyer & ECA have been requested by the motor company to investigate the electrical company who are fully paid up members of ECA.

Long winded but thought some might be interested......I'm just oh so chuffed I didn't do it :^O

 

Mr Sworld

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The 'top bloke' wiring a three phase motor on a single phase! I hate to think what the trainee's are doing then!

 
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I have only wired a couple of star delta motors but always s..t myself in case I have wired them wrong. Touch wood they both worked ok. I try to avoid motors like the plague.

Batty

 

spudmiester

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Was just about to assist with this then read rest of posts.

Would have suggested brooks or other self contained starter, fairly easy to wire up if follow the diagrams.

Have worked with motors big and small for nearly 20 years ,built loads of star delta starters from bits before today, used to build panels, infact still do now and then.

Cant see how motor would work at all on single phase, however it could have been wired up 3 phase with a phase missing somehow, but would have struggled to turn compressor.

Its very possible it was stuck in star, which would explain the high starting current, the getting hot and eventual failure.

The so called 'Top Man' shuold have left well alone.

 
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Just a final point on star- delta motors. The ends of the windings ( a-b-c) are brought out and are marked a1-a2...b1- b2... c1,- c2 connecting these to the starter , as indicated, all should be well . However , if the ends are not marked , you can trace them with the AVO but you don't know which is winding a,b or c . can be difficult

 

spudmiester

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Just a final point on star- delta motors. The ends of the windings ( a-b-c) are brought out and are marked a1-a2...b1- b2... c1,- c2 connecting these to the starter , as indicated, all should be well . However , if the ends are not marked , you can trace them with the AVO but you don't know which is winding a,b or c . can be difficult
Had the very same thing once, on a big pump down a well. No numbers on cores for windings, just six black wires. Took a bit of trial and error before I got them the right way round.

 

spark-doctor

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So the factory gaffer called in a specialist motor firm (cant remember the name) who said the motor is buggered & the reason is down to the top electrician single phasing (was the term used I think) the windings.........basically he'd wired it wrong

Have seen this to many times when inexperienced people try to wire 3 phase motors.

The term "single phasing" is when one of the phases drops out or is not correctly wired and will burn out the next phase in the rotation cycle. By the sounds of it "The Top Spark" bridged out the fuse and the winding burnt out and was running on 2 phases.

Have seen it when a motor was protected by 3 old BS88 fuses, one pops so the operator holds in the start button, next thing is loads of smoke and a nice burning smell

 
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