3 Phase power to workshop, Australian Code?
I plan to have my workshop wired for 3 phase power, to run a turret mill, lathe, air compressor and so on.
All are delta, direct-on-line starter so I don't need a neutral and I planned to run the power out with 3 core + earth cable that I already have.
I just noticed my 3 phase grinder does use a neutral, damn it.
It is used in the contactor of the starter, I may be able to replace the 240 V coil with a 415 V coil to eliminate need for neutral (that is actually what is shown on the schematic).
The workshop already has 240 V so I have a neutral, I assume that one can be used as an alternative solution.
I wondered if there are Australian Electrical Code requirements I need to know or other issues I need to think about before I call the electrician?
I don't have a TIG welder yet, anyone know if they typically require 3+E or 4+E
David
I plan to have my workshop wired for 3 phase power, to run a turret mill, lathe, air compressor and so on.
All are delta, direct-on-line starter so I don't need a neutral and I planned to run the power out with 3 core + earth cable that I already have.
I just noticed my 3 phase grinder does use a neutral, damn it.
It is used in the contactor of the starter, I may be able to replace the 240 V coil with a 415 V coil to eliminate need for neutral (that is actually what is shown on the schematic).
The workshop already has 240 V so I have a neutral, I assume that one can be used as an alternative solution.
I wondered if there are Australian Electrical Code requirements I need to know or other issues I need to think about before I call the electrician?
I don't have a TIG welder yet, anyone know if they typically require 3+E or 4+E
David
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To get 3phases you will need your Electricity Supplier to fit new hardware, (posh name for meter) and services. All services have a neutral as neutral is the earth point at the supply end.
Once you have a new supply installed, always use the correct colour codes or problems will arise in future additions to your workshop.
Once you have a new supply installed, always use the correct colour codes or problems will arise in future additions to your workshop.
- P1: Brown
- P2: Black
- P3: Grey
- Neutral: Light Blue
- Earth: Green/Yellow
Jon,
The OP is in Australia! Codes there are:
Phases: Red, White, (dark) Blue.
Neutral: Black.
Earth: Green/Yellow.
May I suggest in future you fully read questions before jumping in.
I only have experience in NSW but suspect all states are similar, but doing ANYTHING with power wiring requires a strict installation to code and a sign-off by a ticketed engineer.
So ask what you can do, first of all.
The OP is in Australia! Codes there are:
Phases: Red, White, (dark) Blue.
Neutral: Black.
Earth: Green/Yellow.
May I suggest in future you fully read questions before jumping in.
I only have experience in NSW but suspect all states are similar, but doing ANYTHING with power wiring requires a strict installation to code and a sign-off by a ticketed engineer.
So ask what you can do, first of all.
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I already have 3 phase to my meter board, with a spare 3 phase circuit breaker, neutral and earth are connected in accord with Australian standards.
I am not sure if this is the same as UK standards.
The question is if there are any issues if 3 core + earth cable is used out to the workshop, perhaps tied to the neutral in the old 240 V cable run.
Correct!
Yes, I wrote "I plan to have my workshop wired" not "I plan to wire my workshop".
Just want to be sure I don't ask an electrician to do an install that will later require modification.
Like my plan to install 3 core + earth cable, before I realized I needed a neutral for the grinder or a (hypothetical) welder.
The Australian Standard has 4 pin socket outlets and also 5 pin so presumably both are acceptable for power runs.
I don't know if the workshop should be wired as a sub-mains with a neutral.
Actually I am not sure exactly what a sub-mains involves, except that it was mentioned when the electrician ran the 240 V to the workshop.
This replaced the 2 core lamp flex of the previous owner.
Best wishes
David
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Thank you but this links to a site to buy the standard
I don't want to pay hundreds of dollars (each) to read the standards.
Especially because the text of the standard is often opaque, how the local authorities interpret them is what apprentices learn from their apprenticeship.
So I just wanted to see if there were any issues I should watch out for before I call, as I already stated, an electrician.
Best wishes
David
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Thank you for your concern but please read what I already wrote.
Best wishes
David
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With all due respect, your colour code is now out of date.Jon,
The OP is in Australia! Codes there are:
Phases: Red, White, (dark) Blue.
Neutral: Black.
Earth: Green/Yellow.
May I suggest in future you fully read questions before jumping in.
I only have experience in NSW but suspect all states are similar, but doing ANYTHING with power wiring requires a strict installation to code and a sign-off by a ticketed engineer.
So ask what you can do, first of all.
Please see; https://electronics.stackexchange.com/questions/338473/australian-3-phase-colour-code-standard
Please note, Dave Zan, you didn't suggest you had 3 phase already.
You can wire your sockets and power conduit yourself but MUST NOT connect your cable to the mains fuse box. A fully qualified electrician must do the testing and connecting then finally sign the new installation off. Similar to UK standards.
If you use the wrong cable, it will not be passed for safety.
You can wire your sockets and power conduit yourself but MUST NOT connect your cable to the mains fuse box. A fully qualified electrician must do the testing and connecting then finally sign the new installation off. Similar to UK standards.
If you use the wrong cable, it will not be passed for safety.
That's an excellent link.
As I understand it the color codes have not actually altered.
Red,White,Dark Blue are still the recommended cable phase colors, certainly they are what is used in the cable I already have.
The Brown,Black,Grey scheme is an acceptable alternative.
There are rules that cover how to avoid conflict between the two schemes.
Also different rules for "installations" and "equipment".
That illustrates exactly the sort of standard confusion I mentioned above*.
This is more or less the kind of issue that I wanted to know about before it becomes a problem.
So, new standard AS 3000 Rules for 2018, thanks.
*I notice someone else also complained about the need to pay for a standard that should be a "public good".
Best wishes
David
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The Neutral "MUST" be in the same cable and specified size with the 3-phase conductors. What you propose would "work" for a relay coil, true. But you sell the place, the next guy installs random 3-ph gear, assuming a code-compliant neutral. The sum of the N currents may be too large. The separation between cables invokes concerns about circuit reactance. It may not be a problem; it is not something most electricians can analyze. If it smokes, the electrician gets blame. He would rather sell you the Right Cable. Since you seem a handy guy, he may let you crawl the cable, just taking a small added fee for checking your work.
Since this is a point of interpretation, TALK to an electrician before you jackhammer your cable in.
You may say that Maine USA is not "civilized". Sometimes I wonder. However it was not so different in New Jersey which is woefully OVER-civilized (bureaucracy). The home *owner* can do about anything. There may be a $35 Permit, which includes a town Inspection; these are easily evaded. However we may not connect to Company meter, no way no how. If they find their meter-seal tampered they investigate, may disconnect, may prosecute. Unapproved wiring is a misdemeanor; power-theft is a felony.
Thank you.
Actually, "assume" was not how I should have worded it and I was about to edit this when I saw your post, just what I was concerned about and needed to know.
I have been to New Jersey - "civilized" was not a word that came to mind, let alone overly so.
In any case, the rules in Australia are clear, I can cut the trenches and so on, as you say, but definitely must have an electrician for all connections.
In fact the literal interpretation of the rules would even prohibit replacement of a lamp bulb without a safety certificate.
Now that is woeful.
Best wishes
David
Hi Dave,
I apprenticed as a sparky in recent history, and I'd certainly be reticent to touch the switchboard myself, for all I've wired up whole houses.
My dad was a tech dealing with kV voltages in telecoms and the house wiring he did was ...not compliant to standards, and potentially a risk when he s not around and someone does something compliant on top of his work and doesn't check the remainder of whats there.
Are you sure you have a appropriate cable gauge to comply with the standards? Is the conduit and trenching to code? There's a heap more questions to ask, but thats why you get a tradie to do the work...
I apprenticed as a sparky in recent history, and I'd certainly be reticent to touch the switchboard myself, for all I've wired up whole houses.
My dad was a tech dealing with kV voltages in telecoms and the house wiring he did was ...not compliant to standards, and potentially a risk when he s not around and someone does something compliant on top of his work and doesn't check the remainder of whats there.
Are you sure you have a appropriate cable gauge to comply with the standards? Is the conduit and trenching to code? There's a heap more questions to ask, but thats why you get a tradie to do the work...
It's also bad when you find 'licenced tradies' have left loose terminal screw connections that have been arcing.. run power lines closer than the proscribed distance to the gas mains.. run cable around a stud (instead of through) then crush it with the appliance.. grind the earth pin of a 15A appliance to fit into a 10A socket..
Hard to find good help nowadays ;-)
The grinding the pin on a 15amp cord is one of my favorites. Had a customer do that and then call to have his breaker 'fixed' as it kept tripping when welding. 
Scariest one was a distillery install some cowboys did. They ran power for the boiler along the steam output pipe. Basically the insulation was slowly burning away, and next to that source of potential arcing, was a source of pure alcohol vapour.
I had to tell that sparky not to use a blowtorch next to an operating still...
Scariest one was a distillery install some cowboys did. They ran power for the boiler along the steam output pipe. Basically the insulation was slowly burning away, and next to that source of potential arcing, was a source of pure alcohol vapour.
I had to tell that sparky not to use a blowtorch next to an operating still...
Thanks for the examples.
Yes, part of the reason for my question was to know what to keep an eye on, just in case the sparky decided to cut corners or even had momentary brain fade.
Always better to have a second pair of eyes, even smart people do incredibly dumb stuff in a distracted moment.
I knew an experienced tech who suspected a propane leak but could not see clearly because the line was in shadow, so he struck a match...
He survived but I do worry that one day I will have some momentary lapse and people will think "he must have been a dumb bastard to die like that"
Best wishes
David
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Hi David,
I'm an Australian licensed A Class Electrical Contractor.
Depending on the length of the cable run, you might be better off running single insulated building wire in conduit, definitely 3P plus neutral, from your main switchboard, and perhaps an independent earthing arrangement for the shed, this will lower the fault loop impedance, and allow for a small cross section of cable to be used.
Protect the cable with a 3P breaker at the main switchboard, install a sub-board within the shed. Protect all final sub circuits with RCD, which means you can't share the neutral with the 240vAC supply, due to current inbalance under load.
Any competent 2nd year apprentice can calculate the size of the cable required, based on maximum demand, length of the cable run, and de-rating based up on the installation itself, all IAW AS3008 and AS3000.
If you're close to Adelaide, feel free to give me a call. www.sxcelectrical.com.au
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