Naca5, are you able to clarify if all your power outlets are all wired as (in my jargon) L1,L2,PE (for protective earth), or is that just a guess based on one socket providing the L1-L2 = 220V, and L-PE = 127V. Are the 3 phases distributed around the building, but only two phases used for certain outlets/groups.
> That's a "High Leg Delta"
That's clearly not what naca5 has. (The HLD centertap is 180 degrees to each leg, naca5's numbers suggest a 120 degree phase.)
It is good to remind us that there are many ways to connect more-than-2 wires, and to connect small (house) loads on large (neighborhood) power.
That's clearly not what naca5 has. (The HLD centertap is 180 degrees to each leg, naca5's numbers suggest a 120 degree phase.)
It is good to remind us that there are many ways to connect more-than-2 wires, and to connect small (house) loads on large (neighborhood) power.
Hi,
YES the three phases are distributed around the house.
And there is one who uses all (for electric cooktop).
Thanx. In post #36, your photo shows 3 in-coming phases going to a CB or isolation switch, and you indicate that (? after) the isolation device the 3 cables go to a 'black box', and 4 seperate cables from the black box go to your switchboard. Are there any markings on the 'black box'?
Are you able to identify where the 4 wires go to in the switchboard, and is there any indication that the '4th' wire is a neutral, or how it is connected/distributed? In my local TN-C-S, a neutral incoming wire would terminate to a 'neutral bar', from which neutral wires would distribute from for the building.
Are you able to identify where the 4 wires go to in the switchboard, and is there any indication that the '4th' wire is a neutral, or how it is connected/distributed? In my local TN-C-S, a neutral incoming wire would terminate to a 'neutral bar', from which neutral wires would distribute from for the building.
The OP needs to consult a professional electrician to fault diagnose / repair this KILL YOU DEAD mains power distribution systems.
The first thing to have investigated is the integrity of the Earth in that place.
It's well outside the realm of DIY.
No two ways around it.
All DIY work I've had the misfortune to come across in my professional field has been cringe worthy.... and why I loathe to work on domestic installations. At least in the field I work in all work is documented and no dodgy half knowing individual gets near a connection point. Far higher voltages/currents... but far safer.
Hows about drawing a line here and limit diagnostic questions and advice to devices that 'plug in' rather than the high risk mains wiring systems?
My suggestion to 'fix' what appears to be a highly compromised distribution / supply system [damn Neutral isn't bonded to Earth... and 127V can kill] would be to use the mains supply to drive a motor / alternator set.... and find a low impedance Earth in that Home if you can.
The first thing to have investigated is the integrity of the Earth in that place.
It's well outside the realm of DIY.
No two ways around it.
All DIY work I've had the misfortune to come across in my professional field has been cringe worthy.... and why I loathe to work on domestic installations. At least in the field I work in all work is documented and no dodgy half knowing individual gets near a connection point. Far higher voltages/currents... but far safer.
Hows about drawing a line here and limit diagnostic questions and advice to devices that 'plug in' rather than the high risk mains wiring systems?
My suggestion to 'fix' what appears to be a highly compromised distribution / supply system [damn Neutral isn't bonded to Earth... and 127V can kill] would be to use the mains supply to drive a motor / alternator set.... and find a low impedance Earth in that Home if you can.
Sounds very unlikely
but you probably need one if you want to install a new light fixture.
False.
The major problem here is each State has Licensing regimes BUT all fixed wiring work must comply to an Australian [including New Zealand] wiring rules Standard.
Appliances are a different matter... different qualification.
Due to provincial attitudes that stem from Colonial times [pre Federation] it's doubtful any form of National License will ever happen... and so some guys have to acquire a License for every State they may work in at the time. Costly exerciser after going through years of slave labour as an Apprentice plus years working in the field prior to qualifying for such a license.
It's justified when you see the stupidly dangerous stuff done by DIY hacks... and any older place is sure to have bodgy business lurking in the roof or walls or layer upon layer of similar add-on work done by some 'old mate' paid in grog and then without any formal test safety certificate issued. The last guy to work in a place maybe all well and good test and issue certificate, but they are in essence responsible for the whole installation including DIY dangers lurking behind a wall plate.
99% of the time I've seen insulation tape layered over some connection there is something dodgy been wrapped up by some DIY ********.
This, this is why I refuse to work in the DIY riddled domestic field - too professionally risky.
Different Standards apply to different types of equipment eg. SCA's have a specific Standard relating to construction and derating of conductors.
A separate type of license to do Network wiring systems...
Principal concerns relate to Earthing and exclusion of equipment in zones deemed hazardous eg Bathrooms and other wet areas.
Anyhow, moderation - I'm a member of another forum based here in Australia initially started relating to internet service provision. Any DIY electrical work threads of Licensed works nature are deleted quickly, because the forum could be liable for aiding and abetting illegal works activity.
And don't you hear the whining and complaints about 'trade secrets' and 'protection'... never mind the protection of every individual that may haplessly suffer in future due to idiots messing around with stuff they have no real idea or training.
You would not believe the questions asked on how to fix, modify or install by people who wouldn't know how to use a basic multimeter let alone how to fault diagnose or safely install wiring systems.
Same is best applied here too... as I note others have called for earlier in this thread.
I've been to Australia, spent 6 months there in the early 90's, travelling and working between Dandenong and Bundaberg, I have no problem believing everything you say! I mean..drive through bottle shops! haha.The state to state disparity struck me at the time, but it was related to hitchhiking, in Victoria it was encouraged with "hitchhiking stations", whilst in Queensland I believe it was illegal. (can't be many words with a double "h".........)
chances for survival are better...
compared to direct connection to a 3 phase line, if you use an isolation transformer, there is no path for short circuit currents to flow to ground....
not so hard to imagine....
For nearly every location, three phase faults produce the maximum short circuit current. The only exceptions to this are locations where the zero sequence impedance is very low. This is either very close to the secondary of a delta/wye transformer or very close to a solidly grounded wye generator. Just a very short run of cable (service drop would be enough) and you are back to 3P faults being highest.
Can explain why this is, but probably irrelevant to your point, which is that an ungrounded isolation transformer allows a single unintentional ground without any appreciable current flow.
Regarding residential power systems, I am not aware of any country standardizing or even allowing ungrounded service. IEEE is pretty clear on discouraging ungrounded systems as well, as they carry a number of undesirable ramifications; residential and industrial. If one wants to run isolation transformers inside their audio equipment, that's a different consideration.
I would be curious to have the OP re-measure their voltages, because it is concerning that no phase conductor (including the neutral) appears to be grounded.
here in our country, drop wires are two conductors,
one bare and the other insulated,
the bare core is neutral and the insulated wire a phase or line wire,
derived from a single phase pole transformer.....
grounding is alsmost non existent....
but in commercial establishments, there is a grounding system...
having lived and worked in Singapore for four years, i know for
a fact that since the area is prone to lightning strikes,m
their grounding systems are pretty elaborate,
air finials on the roof with copper lattice networks from the
roof and getting down to earth on all corners of the structure,
very elaborate, and this is just for protection from lightning strikes...
i remember in the 70's our college instructor did the calculus for
three phase shorts, and guess what, line to ground short
produced the maximum short corcuit current...
one bare and the other insulated,
the bare core is neutral and the insulated wire a phase or line wire,
derived from a single phase pole transformer.....
grounding is alsmost non existent....
but in commercial establishments, there is a grounding system...
having lived and worked in Singapore for four years, i know for
a fact that since the area is prone to lightning strikes,m
their grounding systems are pretty elaborate,
air finials on the roof with copper lattice networks from the
roof and getting down to earth on all corners of the structure,
very elaborate, and this is just for protection from lightning strikes...
i remember in the 70's our college instructor did the calculus for
three phase shorts, and guess what, line to ground short
produced the maximum short corcuit current...
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