3 phase plug wiring

Talk Electrician Forum

Help Support Talk Electrician Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Status
Not open for further replies.

Toddy

Member
Joined
Dec 30, 2020
Messages
8
Reaction score
0
Hello all

hopefully some can help

ive just purchased a used 3 phase machine that has had the plug cut off, the colour of the wires are black, blue , brown and green/yellow. I’m assuming that the green/yellow is obviously earth and the others are the 3 lives, can anyone confirm which should go to L1, L2  and L3, 

I bought the machine from an auction (not eBay) bankrupt company,  originally it was wired into a 5 pin plug along with another identical machine, the person who purchased the other machine collected theirs before me and they kindly cut the lead from my machine leaving them with the plug, any help would be much appreciated 

many thanks

 
Has the machine got an integral isolator? they are usually marked there so you can see what colour is which. Please check the earth goes to the frame too . Wouldn't be the first time I have seen it used as a neutral when its come from a farm.

 
Has the machine got an integral isolator? they are usually marked there so you can see what colour is which. Please check the earth goes to the frame too . Wouldn't be the first time I have seen it used as a neutral when its come from a farm.
It’s a Blum mini press used for drilling hinge holes in cabinet doors it’s  come from a well set up kitchen manufacturing company there is an isolated on the front of the machine itself and also a power button to start it, it also has an air line connected to it which operates the plunge action

Is there a way I can add a screen shot of the machine to this post

 
It Also depends what the phase rotation is in your building!,

is it JUST a motor ? Or has it got auto stops, limit switches etc.?
As far as I know the motor has one speed, I’m not sure if it’s activated when you press the button for the plunge action and automatically stops when the plunge returns or if you have to manually stop and start the motor

 
If there are directional,stops,on it then rotation direction is crucial

i have seen lots of car ramps screw themselves out of the ground due to wrong phase rotation

i would look for A rotation direction arrow....should be obvs if it is just a drill

connect it up then try it with hand on isolator to turn it off after a split second and see which way it's going....but that's just me as I have been known to do the odd machine now and again

 
Safest way is manually wind the motor to mid travel, start it, and see if the motor travels in the expect direction. If not kill the power PDQ.

 
is there any devices inside to detect incorrect rotation?

failing that, if spinning backwards will/may result in damage then probably easiest to disconnect motor output and power it up. if going wrong way wont cause damage then power it up briefly to check which way its going

 
is there any devices inside to detect incorrect rotation?

failing that, if spinning backwards will/may result in damage then probably easiest to disconnect motor output and power it up. if going wrong way wont cause damage then power it up briefly to check which way its going
As far as I know the power is solely to make the motor spin, the plunge side. Of things is all pneumatic although there is an illuminated button to activate the plunge

 
Sorry to throw a spanner in the works but I have looked a a load of these machines on the net   not seen a 3 phase one . Have a look there must be a rating plate somewhere to show voltage etc. 

. If 3 phase the motor spins clockwise shown from the motor cowl. ie looking at the top of the motor .  Hope this helps

 
Sorry to throw a spanner in the works but I have looked a a load of these machines on the net   not seen a 3 phase one . Have a look there must be a rating plate somewhere to show voltage etc. 

. If 3 phase the motor spins clockwise shown from the motor cowl. ie looking at the top of the motor .  Hope this helps


a very brief look at the catalogue on the Blum website shows they are 3 phase...

 
Sorry to throw a spanner in the works but I have looked a a load of these machines on the net   not seen a 3 phase one . Have a look there must be a rating plate somewhere to show voltage etc. 

. If 3 phase the motor spins clockwise shown from the motor cowl. ie looking at the top of the motor .  Hope this helps
seems they do a 3 phase version after all    https://publications.blum.com/2018/catalogue/en/603/#zoom=z

 
Agree with a lot of the other comments made on here, if you are not experienced with 3 phase electrics you could end up doing a lot of damage, I've known certain types of machine 'written off' by getting the direction of phase roatation wrong, I assume you have saved a few quid by buying the machine the way you did. It is probably advisable at this point to employ the services of a competant spark to connect it up for you, not only to avoid damaging the machine but also since it is 3 phase I'm assuming it's for a commercial use rather than playing about with in the garden shed, so if anything did go wrong you could have the HSE coming at you.

 
Agree with a lot of the other comments made on here, if you are not experienced with 3 phase electrics you could end up doing a lot of damage, I've known certain types of machine 'written off' by getting the direction of phase roatation wrong, I assume you have saved a few quid by buying the machine the way you did. It is probably advisable at this point to employ the services of a competant spark to connect it up for you, not only to avoid damaging the machine but also since it is 3 phase I'm assuming it's for a commercial use rather than playing about with in the garden shed, so if anything did go wrong you could have the HSE coming at you.
That’s why I’ve asked on here, I’m no spark but im more than capable of wiring a plug, 

but so far I’ve still no confidence in wiring it up 

Yeah 

I think on the plate it does rate it from 220 to 415 thereabouts 

 
That’s why I’ve asked on here, I’m no spark but im more than capable of wiring a plug, 

but so far I’ve still no confidence in wiring it up 

Yeah 

I think on the plate it does rate it from 220 to 415 thereabouts 
The problem is a lot of us know about 3 phase but without a schematic drawing or pictures of the isolator etc we haven't much of an idea, normally using that cable you could take a stab at the colours but as I said it could get very expensive if you get it wrong, a 3 phase 4 core flex is normally L1 brown, L2 black and L3 grey , with the green and yellow as earth, but what you have here is a little odd,  normally those colours would be used on a single phase job, brown being permanent live, black being a switched live and blue being a neutral., the fact it was on a 5 pin plug also throws in other issues, a 5 pin has 3 lives a neutral and an earth, now is it using 3 lives and it just happened to be connected to a 5 pin plug, a lot of places are wired in TPNE, as it makes it easier to move equipment around, it's much easier to have a neutral and not need it tan not have one and find you need one.

As I said, it could be just 3 phase, not needing a neutral, or it could even be 2 phase neutral and earth, it does exist, there are a lot of uncertainties and only one absolute certainty, wire it wrong and it will get VERY expensive to put it right. I once had a all to a job where a bloke was installing something, it was easy, it was only 5 wires, or that's what he thought, by the time he'd decided to call me, "is it normal for these things to smoke on start up", tha damage was done, it was a couple of weeks and about three and a half grand later before he got the machine running, but it was only a few wires. Please DON'T try it.

 
The problem is a lot of us know about 3 phase but without a schematic drawing or pictures of the isolator etc we haven't much of an idea, normally using that cable you could take a stab at the colours but as I said it could get very expensive if you get it wrong, a 3 phase 4 core flex is normally L1 brown, L2 black and L3 grey , with the green and yellow as earth, but what you have here is a little odd,  normally those colours would be used on a single phase job, brown being permanent live, black being a switched live and blue being a neutral., the fact it was on a 5 pin plug also throws in other issues, a 5 pin has 3 lives a neutral and an earth, now is it using 3 lives and it just happened to be connected to a 5 pin plug, a lot of places are wired in TPNE, as it makes it easier to move equipment around, it's much easier to have a neutral and not need it tan not have one and find you need one.

As I said, it could be just 3 phase, not needing a neutral, or it could even be 2 phase neutral and earth, it does exist, there are a lot of uncertainties and only one absolute certainty, wire it wrong and it will get VERY expensive to put it right. I once had a all to a job where a bloke was installing something, it was easy, it was only 5 wires, or that's what he thought, by the time he'd decided to call me, "is it normal for these things to smoke on start up", tha damage was done, it was a couple of weeks and about three and a half grand later before he got the machine running, but it was only a few wires. Please DON'T try it.
I certainly won’t be doing anything until I’m 100% about the wiring, like you say it was the blue that threw me, if had been grey I wouldn’t have even posted on here, I did wonder if there was such a thing as 2 phase with a neutral. I’ll try and track the buyer of the other machine and see if they can confirm the wiring in the original plug

 
I certainly won’t be doing anything until I’m 100% about the wiring, like you say it was the blue that threw me, if had been grey I wouldn’t have even posted on here, I did wonder if there was such a thing as 2 phase with a neutral. I’ll try and track the buyer of the other machine and see if they can confirm the wiring in the original plug
Best one is to contact the manufacturer, they are pretty helpful normally, I do have an idea about how it would be wired using the cable you describe but I won't say anything without seeing it, as I said it can get very expensive if it all goes wrong, good luck with it anyway.

 
Status
Not open for further replies.
Top