Thread: 3 phase plugs

Stuart
dredging my memory from over 35 years ago, 3 phase comes in two "flavours" star and delta
one uses three active wires, the other three active plus a neutral
I don't remember which is which
I do remember that HV transmission wires are 3 active, but the LV street circuits are 3 active + neutral.

Do you know if your machines use 3 active + earth, or 3 active + neutral + earth ?
It could make a difference to your wiring

Jekyll and Hyde I might have one, but I have a doz or so 32V ones and all the control relays(contactors if you prefer) are 32V and I have about a wheelbarrow full of them. I had thought of using some 6 pole contactors and forgetting about the plugs.

The mill has 12V 24V and 110V but I'm working on the inverter controls for the shaper and drill. I could just use an on/off switch and may still do but I would like to be able to add things like hour meters

DaveJ Spot on

ian All my stuff is 415V 3 phase (i.e. it goes phase to phase no neutral), my inverter can't do 240V 3 phase and none of my motors would run properly on it.

Stuart

Originally Posted by Stustoys

Jekyll and Hyde I might have one, but I have a doz or so 32V ones and all the control relays(contactors if you prefer) are 32V and I have about a wheelbarrow full of them. I had thought of using some 6 pole contactors and forgetting about the plugs.

The mill has 12V 24V and 110V but I'm working on the inverter controls for the shaper and drill. I could just use an on/off switch and may still do but I would like to be able to add things like hour meters

Stuart

Doh. I just figured out what you're trying to do - you want the hour meter to run off a 32v feed through one of the 5 pins of the 3 phase plug, along with all the contactors etc. Do they make 6 pin 3 phase plugs? LOL.

I wonder whether such a thing as a 32v to 24v transformer exists? Put one on each machine...

Originally Posted by Stustoys

ian All my stuff is 415V 3 phase (i.e. it goes phase to phase no neutral), my inverter can't do 240V 3 phase and none of my motors would run properly on it.

Stuart

Stuart, you're right 3 phase (240V on each) delivers 415 volts when combined.
Where I'm hazy is how the 3 phases are wired into a motor -- I recall a wiring diagram that used 3 actives + neutral and another diagram that just used 3 actives.
What I don't recall is the situations where the two different wiring schemas were used and the relative advantages/disadvantages of each
what I was trying to caution was that due to the two wiring schema a 4th wire might not be an earth

Sort of Jekyll and Hyde. The 32V will run all the control circuits and hour meter/meters of the shaper and the drill. These circuits which would switch the 5th wire (the inverter control) on and off.

They make 5 pin + 2 control sockets and plugs, but I hate to think what they would cost.

As I only want to power an hour meter I'm guessing a resistor will do that job. It may even run just fine on 32V but I don't feel like finding out. Just like my LED lights might run fine on 24VAC when they say 24VDC, I don't feel like finding that out either for the cost of a bridge rectifier.

Stuart

ian
There is no fourth wire on any of my machines, 3 phases and earth.
star/delta depending on the motor is either used so you can have a dual voltage motor or so that you can have a soft start motor.

Stuart

thanks

Originally Posted by Dave J

By the sounds of it, I don't think Stuart is worried about "what if" someone plugs in something latter as he is keeping the gear and it's only to suit him in his shed.

Yes he doesn't appear worried and he has made that clear (and it looks like it's a non-issue now anyway), however I was making the "safety" point because sometimes things happen that are out of our control.

Originally Posted by Dave J

By the sounds of it, I don't think Stuart is worried about "what if" someone plugs in something latter as he is keeping the gear and it's only to suit him in his shed.

Dave

that may be so...but what about when Stuart has left and gone to the big metal workshop in the sky ....he wont be around when it goes to a new owner, and that new owner and not knowing anything as to what has been done may just plug it in to some real voltage thinking its OK to do so

Also, I think you will find that the codes do not just relate to so-called fixed wiring.....the wiring rules cover wiring of machinery, airconditioning units, toasters etc etc...

Originally Posted by eskimo

that may be so...but what about when Stuart has left and gone to the big metal workshop in the sky ....he wont be around when it goes to a new owner, and that new owner and not knowing anything as to what has been done may just plug it in to some real voltage thinking its OK to do so

If you purchased a machine with a loose wire coming from the plug, you'd plug it in and see what happened?

In that case, maybe we do need still more safety inspectors to plug things in for us.

Originally Posted by eskimo

Also, I think you will find that the codes do not just relate to so-called fixed wiring.....the wiring rules cover wiring of machinery, airconditioning units, toasters etc etc...

I think you're wrong. Codes for all fixed wiring. Codes for anything that is plugged in that you sell. Ratings so you are within the current and voltage limits of the equipment you are using.

Originally Posted by Stustoys

I think you're wrong. Codes for all fixed wiring. Codes for anything that is plugged in that you sell. Ratings so you are within the current and voltage limits of the equipment you are using.

??? why then does machinery, aircon units etc etc have to have earthing which meets our codes....this is just one area that I can recall immediately without having to refer to AS3000

under certain conditions an aircon unit, for example, which has a removable access cover plate to access the electrics has to have an earth strap/wire back to the main earth terminal on the unit....this is because our codes calls for it.

a lot of USA stuff has to have electrical mods before it can be sold in Aus...especially the installation of additional earth wires

Because
A. It is part of the fixed wiring
or
B. It is being sold as new
or
C.It comes under the "check and tag" workplace legislation
or maybe even more than one of the above.


Its a little hard for me to prove a negitive.

Hi Stu,

You may not be messing with fixed wiring (AS 3000) but there are plenty of other standards that govern how electrical installations must be carried out, this is to protect both you and the next owner.

The list below is of just some of the other standards relating to electrical installations that I have to abide by for my current project, there are plenty more:

AS 1029 Low Voltage Subcontractors (up to and including 1000V AC)
AS 1049 Telecommunications Cables – Insulation and Sheath – Polyethylene
AS 1125 Conductors in Insulated Electric Cables and Flexible Cords
AS 1429 Electric Cables – Polymeric Insulation – for working voltages 1.9/3.3kV up to and including 19/33kV
AS 1882 Earth and Bond Clamps
AS 1930 Circuit breakers for distribution circuits (up to and including 1000V AC and 1200 V DC)
AS 1939 Classification of degrees of protection provided by enclosures for electrical equipment
AS 2184 Moulded case circuit breakers (up to and including 600V AC, 250V DC) above 10kA
AS 2293 Part 1 Emergency Evacuation Lighting in Building
AS 2643 Fluorescent lamp ballasts of reactive type
AS 2834 Computer Accommodation
AS 3000 SAA Wiring Rules
AS 3111 Miniature over current circuit breakers
AS 3116 Approval and test Specification for elastometer insulated electric cables and flexible cables (for working voltages of 0.6/1kV)
AS 3137 Luminaries
AS 3147 PVC Insulated Electric Cables and Flexible Cables for Working Voltages of 0.6/1kV
AS 3168 Fluorescent lamp ballasts
AS 3260 Specification safety of information technology equipment including electrical business equipment
AS 3439 Low Voltage Switchgear and Control Gear Assemblies for Voltages up to 1000V AC
AS 3548 Electromagnetic interference – Limits and methods of measurement of information technology equipment


Please seek advise from a suitably qualified electrical engineer/contractor.

Regards,
Chris

Chris
Just because there are standards doesn't mean any of them apply to my situation.

There are standards that apply to headlight alignment, do they apply to a car that isn't registered? No
If you buy said unregistered car and want to register it, its your problem to seek advise from a suitably qualified mechanic and have them fixed.

I have extension lead. Do I need to have it tested and tagged? No I don't. If someone buys that extension lead from me it's their responsibility to have it tested and tagged if needed.

Home many houses have Emergency Evacuation Lighting?

Stuart