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.

[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.

[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

[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

[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.

[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

[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?

[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

[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.

[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

[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:

[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! ), I agree that 40Amps would be nice but I think the clipsal 40Amp 3phase outlet costs more than $500 by itself!!! I just couldn't justify that kind of money for one outlet... Regards, Luckyduck

[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...

[Greg Q]

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

[Greg Q]

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?

Greg