DOL starter 415V coil

[netblindpaul]

Well I won't go into the bit of standards that prevents 400V control on 2 motors for compliance with current standards & legislation then.

 

[Hutch118]

Thanks for that wee gem of advice Paul, this is why I rarely come onto this forum for info !!!

Most of the folk are very genuine and helpful while other 'experts' go out their way to make statements like they are know it all. Why make a statement like that? If you want to help, then please help.

If Ive done something wrong, then point out why and where I can get the info so I understand why I went wrong. Is that not easier for you???

 

[plugsandsparks]

FWIW, if it was me i would check the coil voltage first as it wont be the first time..
second i would double check the wiring by "belling", i.e. ignoring any wire numbers just in case a bit of brain fade when numbering (wouldn't be the first time).
Then i would check the resistance of the coil to make sure someone was not having a laugh and marked up a 24V coil as 400V ..)

 

[Darkwood]

Right .... the main issue with simple problems is they sometimes elude you so what i suggest is you take a picture of the set-up im sure it will be clear for us to head you in the correct direction...

If you have not loads connected to contactors and it shorts when hitting start button then it points to a simple wiring issue in your control circuit either through oversight or lack of understanding and you seem clearly creating a short when energising the coil... it may be down to confusion here .... pic of the wiring and contactor will help with indicators of any wires going out of view.

 

[Darkwood]

Thanks for that wee gem of advice Paul, this is why I rarely come onto this forum for info !!!

Most of the folk are very genuine and helpful while other 'experts' go out their way to make statements like they are know it all. Why make a statement like that? If you want to help, then please help.

If Ive done something wrong, then point out why and where I can get the info so I understand why I went wrong. Is that not easier for you???

Although you have not suggested you have exported your control circuit he raises a good point if you have ... if your start stop are remote and you are controlling the coil with 400v then you will be in a possible contravention of regulations ... this is not part of BS7671 and if your don't know what regs it falls within then you shouldn't even be touching this. You shouldn't take offense at such a post as it states a good point if you are offended then reply that you are fully aware and his concerns are not the case or we will obviously question your competence in such an area.

 

[Lucien Nunes]

I know you can become blind to an obvious mistake if you look at it for too long but your meter doesn't! Surely a continuity test across pairs of (dead) supply lines will tell you what is being shorted and when, if you check both by pressing the start button and by pushing the contactor in by hand. Then you will know if it is in the main circuit or the control. If that doesn't narrow it down enough.... post pics!

 

[pepparz]

i would disconnect link from A1 to blue phase and operate start button with power on to see if it takes out supply.this should start to narrow it down.

 

[Silly Sausage]

i would disconnect link from A1 to blue phase and operate start button with power on to see if it takes out supply.this should start to narrow it down.

No no no!!!
You're proposing blowing out a box of fuses until you find the fault! :smilielol5:
I think I'd go with Lucien's advice.

 

[Lucien Nunes]

operate start button with power on to see if it takes out supply.

There seems to be a lot of enthusiasm around for faultfinding with live tests. Inverter drive lacking torque - probably necessary. DOL starter blowing fuses - probably not! Should be able to spot the problem in 3 minutes with an AVO...

 

[pepparz]

No no no!!!
You're proposing blowing out a box of fuses until you find the fault! :smilielol5:
I think I'd go with Lucien's advice.

it means blowing a fuse! the world wont stop turning.
the other way is to mega it while dead,can't be that difficult to find

 

[Marvo]

Should be able to spot the problem in 3 minutes with an AVO...

An avo??

....I'll get my coat.

 

[44ALLAN]

I still have my old avo...............probs well over 50yr old now cos it was old when I 'acquired' it

mmmmmmmm................e-bay or antiques roadshow is the question?

 

[Hutch118]

Sorted out lads, turned out to be a fault on the control transformer. 415v to 115/24.

Thanks for all the help lads, took a wee bit of head scratching and looking at it too long then realised where the fault was.

 

[Brightspark2]

I still have my old avo...............probs well over 50yr old now cos it was old when I 'acquired' it

mmmmmmmm................e-bay or antiques roadshow is the question?

I still have an AVO EFLI meter. I've never had one problem with it, so simple and reliable and tough!...unlike the megger which is in for repair AGAIN!. I don't rate them at all any more.

 

[Darkwood]

Sorted out lads, turned out to be a fault on the control transformer. 415v to 115/24.

Thanks for all the help lads, took a wee bit of head scratching and looking at it too long then realised where the fault was.

Im totally lost now you explained fully how the set-up was wired ...2 contactors, overloads, and control 400v on A1 / A2 via the start stop buttons....
You also said when energised it went bang when the start button was pressed.... ???

Where the hell did the transformer come from and you say its for control 115/24 ..... i though we were on 400v control and surely the 'control' transformer is energised on power up thus the fuses will have blown on power up not after the start button has been hit....

Have i totally missed something here what you just described has nothing to do with your thread opening post so we really had little chance of nailing the problem for you.