# Forum Home Renovation Electrical  3 phase plugs - 4 or 5 pin

## FlyingDuck

I have been contemplating getting 3 phase power to my shed, and while thumbing through the clipsal catalogs for socket outlets, notice you can get 4 or 5 pins (and even more). 
Now, I always thought there would be 5 wires in a three phase cable ie. 3 actives, 1 neutral & 1 earth, hence a 5 pin outlet would make sense.   
What then is a 4 pin outlet for, and what is the combination of wires in the cable? 
In general, what is the common cable & plug/sockets used for 3 phase shed wiring circuits.  Is it a cable consisting of 3 actives, 1 neutral & 1 earth, and a 5 pin outlet - this is what makes sense to me.

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## boban

4 pin is more common as a three phase motor only needs the three actives and an earth.  The 5 pin is found on machines that have a single phase motor somewhere within the machine (like on some edgebanders).  Hence they need the neutral.

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## journeyman Mick

I have 5 pin outlets but the plugs are a mix of 4 and 5. 4 pin plugs will fit into a 5 pin outlet. 
Mick

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## Simomatra

I go along with Boban and Mick. If you install 5 pin plus then any can be plugged in. The good thing about this is that if you get a machine calling for the fifth pin ie the neutral then you can use it. 
The neutral is only used in machines that use the neutral for 240 volt circuitry without the need for a transformer 
It is more common though for the machines to only call for the four pins

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## Markw

Basic electrotech
The potential (you call it voltage) between phases is 415V.
The potential between neutral and any one (1) phase is 240V.
The potential between earth and any one (1) phase is 240V. 
What comes into your house is any one of A, B or C phase plus a neutral wire. All them energy hogs that have three phase have 4 wires - ABC & N. Some people need more than single phase but not three phase for industrial motors so they get AB & N or AC & N or BC & N. 
Neutral is not necessary for the high torque 3 phase motor as there is more power between the phases. Earth is still required for safety.

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## LuckyDuck

FlyingDuck, 
From other posts from you on this website, I assume that you are asking this question about pins because you are considering purchasing FELDER or HAMMER gear... 
As it happens, I have had a lot of trouble getting my FELDER RL160 wired up for use. The FELDER gear does come with 5 pin sockets, but the pins are not in the configuration of the 5 pin Clipsal range. So after many false starts (my electrician first ordered the standard 4 pin outlet; then the standard 5 pin outlet), my electrician finally got me some European outlets which suit the 5 pin European configuration. In the case of the RL160, the neutral wire is required because there is a filter monitoring system which lets me know when the filter needs to be cleaned. 
When the FB540 arrives, I have a European 5 pin outlet waiting for it. I don't think it needs the fifth pin, but I didn't fancy purchasing a new socket (boy is everything 3 phase expensive or what!!?) and having it wired on to my bandsaw. 
Regards, LuckyDuck

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## FlyingDuck

Thanks for the informative replies everyone.  I suppose to be safe, the cable I should use to wire up three phase circuits in my shed would be 4 core + earth, and that the neutral would be available if ever needed. 
Lucky, did you consider replacing your plug on the dusty with an Aussie 5 pin, instead of trying to find a Euro socket?  That way you could just stick with the standard outlets which would suit non Hammer gear as well.   
Where do you find the Euro outlet - what brand, model, cost?

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## soundman

I'm definitely pro 5 pin but thats my entertainment industry bias. 
If you are wiring for a particular machine that needs no neutral there is no technical reason to have either the neutral pin or the wire going there.
Most industrial 3 ph is wired 4 core with 4 pin plugs simply because its much cheaper.  
As for euro plugs.
We will be seeing more & more euro plugs comming in. We've been seeing them for many years in the entertainment industry because a large slice of the gear comes from europe. 
It depends upon what european type plug you are looking for.
The "Marechal" range ( the pale blue ones) are now distributed by clipsal (and they aint cheap, never were). You'll see these quite a bit in McDonalds.
Very nice plug, but not cheap. 
there are some other versions. but any electrical wholesaler who knows his industrial stuff should have no problem ordering it. 
cheers

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## Rossluck

> Thanks for the informative replies everyone. I suppose to be safe, the cable I should use to wire up three phase circuits in my shed would be 4 core + earth, and that the neutral would be available if ever needed.

  Bingo FlyingDuck. That's what my electrician did. His watered-down-for my-ignorance explanation was that three phase motors are so efficient that they rarely need the "return" function of a neutral wire. I don't know about you, but when experts like Markw start talking about potential between phases, I'm lost.  
One thing I'd recommend is at least a 40amp circuit breaker. Mine is 20 and it trips out during welding.

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## andrewsd

To ask some really stupid questions: 
1 What are the benefits of 3 phase over single phase?
2 Can you use a 3 phase machine with single phase power?
3 How much does it cost to have installed? 
Thanks 
Andrew

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## Markw

> To ask some really stupid questions: 
> 1 What are the benefits of 3 phase over single phase?
> 2 Can you use a 3 phase machine with single phase power?
> 3 How much does it cost to have installed? 
> Thanks 
> Andrew

  1. Twice the energy per phase - 240v Vs 415v but you will pay for each kilowatt of energy consumed. Three meters and it all adds up. 
2. No
3. How long is a piece of string :confused::confused::confused:

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## LuckyDuck

Flying, I did consider changing the FELDER machines over to 5 pin clipsal configuration, but it seemed a waste to throw away the 5 pin Euro plug which comes with the machine. While a new 5 pin clipsal male plug costs around $100 each, the female Euro outlet (also 5 pin) only cost me $10 more than for the standard 5 pin clipsal outlet. 
My electrician charged me $300 for each supplied and installed 5 pin Euro 3phase outlet, with 20 Amps. The brand is Hypra, and I am led to believe that this is a high quality product (?) ... The outlet is quite bulky and I do prefer the clipsal configuration, however. 
I paid $2400 to have my house completely rewired from 1 phase to 3 phase, bringing it in from the street, with a new meter box and meters, with a 60 pole circuit board. The $300 for each outlet (mentioned above) included supply and installation of the outlet, and a separate circuit breaker and RCD unit for each circuit. It does get exxy ... but I have no regrets. 
Rossluck (glad the lucks and ducks all have company!  :Smilie:  ), I agree that 40Amps would be nice but I think the clipsal 40Amp 3phase outlet costs more than $500 by itself!!! :Frown:   I just couldn't justify that kind of money for one outlet... Regards, Luckyduck

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## LuckyDuck

> 1 What are the benefits of 3 phase over single phase?

  One more thing, I just recently purchased a 3phase 4hp (3kW) HAMMER motor for my tablesaw (Delta Unisaw). The original motor always overheated because I imported the saw myself from the States and the motor never did like the 50Hz electricity over here -- so it always overheated. 
Anyway, the HAMMER motor is rated at 13Amps. The "same" motor, in 1phase configuration, is rated at 19Amps. Although it costs more to start up, the 3phase motor I bought uses less electricity. That counts as a benefit to me...

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## gregoryq

> To ask some really stupid questions: 
> 1 What are the benefits of 3 phase over single phase?
> 2 Can you use a 3 phase machine with single phase power?
> 3 How much does it cost to have installed? 
> Thanks 
> Andrew

  The motors do not require start or run capacitors, they run cooler and produce more torque (h.p.) for an equivalent case size. Without capacitors, they don't need the failure prone centrifugal switch that single phase motors use to switch between start and run caps.  The motors are also widely available as used items.  
No, you can't. A three phase motor has three hot (or 'active') conductors, and the windings are different. * 
You can also make your own three phase power by making or purchasing a phase converter. A simple 240v three phase converter can be made with a big three phase motor and a box of caps. You can increase this to 415v by adding a step-up buck boost transformer. All of this is way beyond what most Australians consider safe DIY activity. The other option is to employ a VFD at each machine, using single phase input. The benefit here is variable speed across a wide range-ideal for lathes and milling machines where speed changes are often difficult, and on shapers when a router spindle is mounted.
Best of all is to get a sparkie to install a three phase panel and outlets in your shed from the street, unless you are too far from the pole.  
An ePay search for 'three phase' will yield many plugs and outlets at some bargain prices. I wired three machines for less than $40.00 total-depends on the competition on the day. 
Greg

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## gregoryq

> One more thing, I just recently purchased a 3phase 4hp (3kW) HAMMER motor for my tablesaw (Delta Unisaw). The original motor always overheated because I imported the saw myself from the States and the motor never did like the 50Hz electricity over here -- so it always overheated. 
> Anyway, the HAMMER motor is rated at 13Amps. The "same" motor, in 1phase configuration, is rated at 19Amps. Although it costs more to start up, the 3phase motor I bought uses less electricity. That counts as a benefit to me...

  Did it fit without modification? And was the old motor a Baldor, by chance?  
And what are you doing with a unisaur? Shouldn't you have a saw that slides? :Wink:   
Greg

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## falz

4 pin doesnt have an earth, if i can remember correctly

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## LuckyDuck

> Did it fit without modification? And was the old motor a Baldor, by chance?  
> And what are you doing with a unisaur? Shouldn't you have a saw that slides?  
> Greg

  Yeah, yeah, I wish I had a slider...
But no it didn't fit without some modification. I'm in the process at the moment of getting the pulley drilled out (from 19mm to 25mm) for the new shaft, and I have to make up some adaptors to bolt on the new motor to the Unisaw trunnion. Alas, no Baldors here; the original "Delta" motor is made by Marathon Electrics, and it is a beauty (despite the wrong winding). Got any advice on what I should do with it? I was thinking about making a spindle sander or something similar that might not take too much grunt to overheat it again?? Regards

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## soundman

The 4 pin plug has no neutral.  
three phase motors are (generaly) smaller, cheaper, hve less to go wrong with them than an equavelent single phane motor.

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## falz

My bad, lol yer ur right, No Neutral

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## FlyingDuck

Not having an electrician handy to ask this, does anybody know if it is possible & legal to have both 3 phase outlets & 1 phase outlets sharing the SAME 3 phase circtuit, or do you have to separate them into different circuits? I am assuming that you would wire up the 1 phase outlet using any 1 of the 3 hot wires available in the circuit.

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## soundman

:eek: :eek: 
You certainly can not have mixed single phase and 3 phase outlets on the same breaker / circuit. 
While this is an over simplifacation of the regs this is the way it should be.
any single phase  15 amp or over, one outlet, one breaker.
any three phase one outlet, one isolator, one breaker. 
cheers

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## FlyingDuck

Thanks Soundman, knew I could rely on you. 
By the way, do you happen to have the clause number from the Australian Standards where it talks about the number of three phase outlets on a circuit?   
I have read the wiring rules during a very basic intro electricians course years ago (we didn't cover three phase, but I am an expert in single phase :Biggrin:  ), but can't recall reading any rules about three phase in there.  I still have got a copy, so can look it up. 
And besides the legal requirements for number of GPOs on a circuit etc, could it theoretically be done?

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## thatirwinfella

> Not having an electrician handy to ask this, does anybody know if it is possible & legal to have both 3 phase outlets & 1 phase outlets sharing the SAME 3 phase circtuit, or do you have to separate them into different circuits? I am assuming that you would wire up the 1 phase outlet using any 1 of the 3 hot wires available in the circuit.

  you're sort of in the ball park. in terms of a shed, if it had three phase and single phase power, it would have the three phase cabling running to the shed, and thats it. All three phases would be used for three phase :eek:  and any or all of the three phases could be used on their own as a single phase circuit. In terms of circuit breakers and switchboards, they three phase circuits would all be protected by three phase circuit breakers and the single phase circuits would be protected by single phase circuit breakers.   
to finally answer your question, it wouldn't all be on one circuit but it could all be provided from one switchboard.

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## gregoryq

> Yeah, yeah, I wish I had a slider...
> But no it didn't fit without some modification. I'm in the process at the moment of getting the pulley drilled out (from 19mm to 25mm) for the new shaft, and I have to make up some adaptors to bolt on the new motor to the Unisaw trunnion. Alas, no Baldors here; the original "Delta" motor is made by Marathon Electrics, and it is a beauty (despite the wrong winding). Got any advice on what I should do with it? I was thinking about making a spindle sander or something similar that might not take too much grunt to overheat it again?? Regards

  Marathon makes nice motors. I'd consider using it for a cyclone dust extractor (I'm assuming 3 h.p.). The 50 Hz won't be a problem if you get a properly sized impellor. That or the spindle sander, or for bandsaw power. 
Greg

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## FlyingDuck

Hi Greg, I think you may have just posted that in the wrong thread???

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## FlyingDuck

[quote In terms of circuit breakers and switchboards, they three phase circuits would all be protected by three phase circuit breakers and the single phase circuits would be protected by single phase circuit breakers. quote] 
Yes, that is of course the way it would actually be done - I would not contemplate mxing them up in reality. But I am still curious if it would be theoretically possible to take one of the actives, the N & E from a three phase circuit and use them for a 240V single phase outlet.  There is suppossed to be 240V between any one active & N, so that should work.  Might be problems in sharing the N though.

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## gregoryq

I think that quote was from last week, referencing some off-topic aspect of this thread. LuckyDuck has a left-over single phase motor of good pedigree that's looking for a new job, hence the comment. 
Greg

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## gregoryq

> [quote In terms of circuit breakers and switchboards, they three phase circuits would all be protected by three phase circuit breakers and the single phase circuits would be protected by single phase circuit breakers. quote] 
> Yes, that is of course the way it would actually be done - I would not contemplate mxing them up in reality. But I am still curious if it would be theoretically possible to take one of the actives, the N & E from a three phase circuit and use them for a 240V single phase outlet.

  Yes, it is. But if the three phase is of the locally manufactured variety, from a rotary or static phase converter, you can drag down the voltage of one of the legs by tapping off an additional single phase demand.

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## thatirwinfella

> [quote In terms of circuit breakers and switchboards, they three phase circuits would all be protected by three phase circuit breakers and the single phase circuits would be protected by single phase circuit breakers. quote] 
> Yes, that is of course the way it would actually be done - I would not contemplate mxing them up in reality. But I am still curious if it would be theoretically possible to take one of the actives, the N & E from a three phase circuit and use them for a 240V single phase outlet. There is suppossed to be 240V between any one active & N, so that should work. Might be problems in sharing the N though.

  yeah, it would work, and there are no problems in sharing the neutral. a neutral, by law, is not allowed to be switched, so regardless of how many different circuits there are in an installation the neutral is continuous. the only problem with taking an active and adding a neutral is that you would now need two to three kilowatt/hour meters for the supply to guage how much power you're using. with purely 3 phase equipment it's a balanced load, so you can get away with one meter

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## gregoryq

[QUOTE=thatirwinfella]  

> the only problem with taking an active and adding a neutral is that you would now need two to three kilowatt/hour meters for the supply to guage how much power you're using. with purely 3 phase equipment it's a balanced load, so you can get away with one meter

  Is knowing the power usage that important to the hobby user? I can see reasons for industry, but for my small shop, I rely on a hand-held diagnostic meter. I wonder now what I'm missing. 
Greg

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## FlyingDuck

Thanks for the replies.  Okay, I think we have established that it _would_ work.  Now I am curious if it ever gets done in reality, or is this something an electrician would never contemplate doing?  And is it legal or not?  I still would like to find a clause in the Standards which has a ruling about this.

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## LuckyDuck

> Marathon makes nice motors. I'd consider using it for a cyclone dust extractor (I'm assuming 3 h.p.). The 50 Hz won't be a problem if you get a properly sized impellor. That or the spindle sander, or for bandsaw power. 
> Greg

  Thanks Greg, I was thinking about a spindle sander but perhaps I'll have to explore this possibility in another thread!  :Smilie:   (I've already got excellent dust extraction.) Luckyduck.

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## gregoryq

> Thanks for the replies.  Okay, I think we have established that it _would_ work.  Now I am curious if it ever gets done in reality, or is this something an electrician would never contemplate doing?  And is it legal or not?  I still would like to find a clause in the Standards which has a ruling about this.

  They must teach you well up there! :Biggrin:   
Three thread hijack attempts rebuffed without even raising a sweat! :Wink:

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## thatirwinfella

> Is knowing the power usage that important to the hobby user? I can see reasons for industry, but for my small shop, I rely on a hand-held diagnostic meter. I wonder now what I'm missing. 
> Greg

  well your supply company is still going to have to charge you for power used. Perhaps you're thinking of power factor, rather than power used?    

> Thanks for the replies. Okay, I think we have established that it _would_ work. Now I am curious if it ever gets done in reality, or is this something an electrician would never contemplate doing? And is it legal or not? I still would like to find a clause in the Standards which has a ruling about this.

  the only regs i can find that may be of use are 3.5.2a&b which is about the minimum size of the neutral conductor for multiphase circutis. and 5.5.2.2 which is the minimum size of an earthing conductor. because you'll be adding extra load to the neutral and earth you may have to upgrade them.  
Hypothetically, if you're going to see this through to physical form it would be easier to run a single 2 core and earth cable from a single phase circuit breaker to your socket, then to run a single core cable from a circuit breaker AND a neutral and earth from somewhere else.

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