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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Electrical Questions >> 3 phase plug https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1099521789 Message started by doug on Nov 3^rd, 2004, 10:43pm

Title: 3 phase plug
Post by doug on Nov 3^rd, 2004, 10:43pm

could you tell me hoe to wire up a 3 phase plug for a mig welder i know the top thick pin is the earth but going clockwise from there ie L1,L2and L3 what colour wires goes where ?

Title: Re: 3 phase plug
Post by plugwash on Nov 3^rd, 2004, 11:51pm

what color wires does it have? and how many?

if there are only 4 wires (including the earth) then there will not be a neutral

there are a few possibilities

L1-red
L2-yellow
L3-blue
N-black

L1-brown
L2-black
L3-black
N-blue

L1-brown
L2-black
L3-grey
N-blue

Title: Re: 3 phase plug
Post by L.Spark on Nov 4^th, 2004, 12:10am

Quote:

L1-brown
L2-black
L3-black
N-blue

Whats that mean to be? ???

Title: Re: 3 phase plug
Post by plugwash on Nov 4^th, 2004, 12:55am

5 core flex has been brown/black/black/blue/g&y for quite some time accross most of europe (including the UK)

it may be changeing to brown/black/grey/blue/g&y now but its going to take a while for that to filter through

Title: Re: 3 phase plug
Post by L.Spark on Nov 4^th, 2004, 12:58am

Title: Re: 3 phase plug
Post by The_Trician on Nov 4^th, 2004, 2:08am

wrote on Nov 3^rd, 2004, 10:43pm:

could you tell me hoe to wire up a 3 phase plug for a mig welder i know the top thick pin is the earth but going clockwise from there ie L1,L2and L3 what colour wires goes where ?

It doesn't bloody matter mate, so long as the motor for the cooling fan (if fitted) is blowing or sucking the right way.
Phase rotation shouldn't matter for welding purposes.
Most 3ph welders actually only use 2 phases for the welding circuit but the cooling fan motor rotation is all-important - check the Manual for further info.

TT

Title: Re: 3 phase plug
Post by plugwash on Nov 4^th, 2004, 2:31am

wrote on Nov 4^th, 2004, 2:08am:

It doesn't bloody matter mate, so long as the motor for the cooling fan (if fitted) is blowing or sucking the right way.

swapping two phases is unlikely to cause damage if you catch it reasonabbly quick (because things are running backwards)

swapping a phase and neutral could well cause a rather nasty bang

Title: Re: 3 phase plug
Post by The_Trician on Nov 4^th, 2004, 12:34pm

True Plug, forgot about Neutral - mind you, most of the multi-phase sets I've seen/used don't employ a Neutral but its been a while!

TT

Title: Re: 3 phase plug
Post by doug on Dec 13^th, 2004, 10:48pm

finaly got round to checking the wire coulors they are yellow,brown,blue and black hope you can tell me what goes where :)

Title: Re: 3 phase plug
Post by L.Spark on Dec 13^th, 2004, 10:59pm

It could be

Brown = L1\Phase 1
Yellow = L2\Phase 2
Blue = L3\Phase 3
Black = Neutral

But I could be wrong ::)

Title: Re: 3 phase plug
Post by plugwash on Dec 13^th, 2004, 11:56pm

is there a green/yellow for earth as well?

personally given such an odd combination i would ring the manufacturer and ask them

Title: Re: 3 phase plug
Post by The_Trician on Dec 14^th, 2004, 12:46am

You could try metering the cables out to see what they are connected to.

Brown. blue & black are lives & yellow is earth I reckon, but test em out all the same.
Meter between the yellow and the welder case and see if you get a reading.

Title: Re: 3 phase plug
Post by doug on Dec 15^th, 2004, 11:28pm

the yellow wire is yellow green
i tryed metering the earth wire not to sure on how to use a multi meter i put the red on the end of the yellow green wire and the black on the welder caseing could not get any numbers to come up on the meter the only thing it did was bleep when it turned the knob round to the sound sign hope that made sence !!

Title: Re: 3 phase plug
Post by Chaddy on Dec 15^th, 2004, 11:48pm

That beep means there is continuity between the yellow/green and the welder case. This is the earth.

Title: Re: 3 phase plug
Post by L.Spark on Dec 16^th, 2004, 12:20am

Quote:

the yellow wire is yellow green

Well then that already says something important, Yellow on it's own is a phase colour or Live, Yellow & Green Stripped is always earth, Just a matter of making sure you know what the other colour cores do now.

Title: Re: 3 phase plug
Post by Lectrician on Dec 16^th, 2004, 7:58pm

Sounds like he has three phase and an earth.

Put you yellow/green to the earth pin. The other tree, I would strongly guess are the phases. Go as per TT suggested. Any order, and check the fan runs correctly. If it runs in reverse, swap ANY two phases.

Title: Re: 3 phase plug
Post by ban-all-sheds on Dec 17^th, 2004, 9:19pm

Sounds to me like someone who doesn't even know how to use a multimeter should not be wiring up a 3-phase appliance.

This could be the family farm, or workshop, or it could be somewhere with all sorts of public liability and general insurance issues surrounding unqualified people working on electrical items.

(test)