How do I tell if I have 3 phase power?

[thatirwinfella]

you don't neccessarily need to get two more centameters.

If the sparky who originally wired the board bothered to bring three phases in, they may be balanced reasonably equally, eg fairly equal maximum demands. Just using one centameter would give an indication per phase, and you could multiply by three to get a rough idea of the total amps being drawn. If you were to purchase the centameters to have ready for the sparky, get him to measure the current drawn per phase and if they are roughly equal, only install one, then get a refund on the spare units.

alternatively, a three phase centmeter may be available, with a single display, three current transformers [the coil which goes around the conductors] and a switch to choose which phase the display will show the current for. This may be cheaper [or more convenient space wise] then two more units.

I'd recommend a major board upgrade if any renovations are to be done in the future. It probably wouldn't be too hard to terminate the existing circuits to terminal strips [if ther isn't much length spare] in an existing cabinet, then run them through breakers and rcds in a vertical mounted board adjacent.

An as others have said, this is a sub par installation. I'm an apprentice, and I would be disppointed if my work looked like.

[Timmo]

can you post a photo of the fuses and/or the feed up on your roof?

[Trav]

Thanks for the comments.

The centameter is already equipped to deal with three phases - all I need is two more sensors, which I've now ordered. It simply adds the power consumtion across all three phases.

I can arrange a photo of where the power from the pole reaches the house if that is helpful. I'm not sure how it gets from that end of the house to the circuit board you see, as the house is a flat roof. I will investigate more over the weekend and report.

Thanks again

Trav

[Trav]

I had a look at the power cable joining the house last night. It was a bit dark, but it appears there are three cables, twisted together, from the pole to the house. As it approaches the house, the are split apart and join the house separately - ie each one goes through one of those ceramic 'bells' before entering into the roof cavity.

I presume, from this, that it is definitely three phase.

Incidently, what does a three phase power point look like? Is it essentially the same as a GPO, or is it some great big industrial contraption with a flip-shut lid? Any photos?

Cheers

Trav

[NCArcher]

ie each one goes through one of those ceramic 'bells' before entering into the roof cavity.
The 'ceramic bells' are the service fuses.

I presume, from this, that it is definitely three phase.
Yes it is definately 3 phase

Incidently, what does a three phase power point look like? Is it essentially the same as a GPO, or is it some great big industrial contraption with a flip-shut lid? Any photos?
Big industrial contraption with a flip shut lid pretty much sums them up.
Something like this

[Wood Butcher]

If there are only three wires then it is not three phase. Three phase has four wires (the three phases plus neutral) . Also those ceramic bells are not necessarily to be service fuses, but just insulators. Service fuses are normally located on the pole where the supply comes from.

[Barry_White]

Trav

Just because you have three phase it doesn't mean you have anything that is operating on three phase. It may just mean that all your circuits are spread across the three phases and give you depending on the size of your mains coming in to have more capacity than if you had single phase.

What it does mean is that it gives you the capacity to get some great three phase workshop toys.

Woodbutcher in NSW at least the service fuse can either be on the supply pole or at the point of attachment on the house.

As Woodbutcher says if it is three phase there should be four wires coming in unless the neutral is hiding some where.

[rileyp]

you don't neccessarily need to get two more centameters.

If the sparky who originally wired the board bothered to bring three phases in, they may be balanced reasonably equally, eg fairly equal maximum demands. Just using one centameter would give an indication per phase, and you could multiply by three to get a rough idea of the total amps being drawn. If you were to purchase the centameters to have ready for the sparky, get him to measure the current drawn per phase and if they are roughly equal, only install one, then get a refund on the spare units.

alternatively, a three phase centmeter may be available, with a single display, three current transformers [the coil which goes around the conductors] and a switch to choose which phase the display will show the current for. This may be cheaper [or more convenient space wise] then two more units.

I'd recommend a major board upgrade if any renovations are to be done in the future. It probably wouldn't be too hard to terminate the existing circuits to terminal strips [if ther isn't much length spare] in an existing cabinet, then run them through breakers and rcds in a vertical mounted board adjacent.

An as others have said, this is a sub par installation. I'm an apprentice, and I would be disppointed if my work looked like.

lol yeah the guy that did that beautiful worked balanced the phases perfectly
You suggested replacing the board? Why he has 13 poles not being used atm that I can count.
The circuit breakers used are high qaulity breakers and will last almost forever in a domestic enviroment.
The only problem this man will have with this board is getting extra breakers as they will cost probably 3 times the price of std breakers or more...
The biggest newest plastic domestic type board would not compare to a what he has atm sorry.
Keep what you have and dont worry about the mess inside as long as everything is terminated correctly. The fact all the cables are a little long is good imho as they allow your sparky to reconfigure what you have if need be.
If your after breakers call your local industrial sparky and see if he has any he wants to sell!
When we scrap older boards like this we normally keep 6 or 8 of each cb size and throw them on the shelf in the factory for when we do work on another building or another area and need to install one of these type breakers.
my 2 cents
cheers Rileyp

[Timmo]

If there are only three wires then it is not three phase. Three phase has four wires (the three phases plus neutral) . Also those ceramic bells are not necessarily to be service fuses, but just insulators. Service fuses are normally located on the pole where the supply comes from.

Service fuses on ActewAGL LV feeds are NOT on the pole!!!!!!!! Those bell thingies are the fuses holders, superceded now by single use plastic holders. Actew supplies a direct live feed to fuses on the roof (or to the meter box on newer underground feeds).

In the ACT if there are three bells then chances are it's 3 phase connected. The neutral does not pass through a bell on a 3 phase hookup.

You can have a 3 phase core on a single phase connection but split the active and neutral over two cores each. In this case there will be either one or two bells.

[Wood Butcher]

Service fuses on ActewAGL LV feeds are NOT on the pole!!!!!!!!

Well sorry but there regularly are in queensland! I never said they definately weren't fuses.

[Timmo]

Well sorry but there regularly are in queensland! I never said they definately weren't fuses.

Didnt mean to be blunt. Apologies and man hugs.

we are talking about an ACT install and ActewAGL is the relevant supply authority. I know NSW also have pole mounted fuses and I'm sure other states do too but ill refrain from speculating on codes I'm not familiar with. I just think it can be a bit dangerous if someone could be led to believe that a feed to their house could be dropped without either a physical disconnection from your LV supply pole or a local service outage.

Basically in Canberra if your house is wire up and your neighbours lights are on, then, chances are, your roof has live terminals on it.

I did forget to mention that the neutral is usually just crimped and taped underneath the fuses in my previous post. More man hags for all concerned

[nev25]

If your after breakers call your local industrial sparky and see if he has any he wants to sell!

I wouldn't worry about buying These CB under the new regs they would be allowed to be installed.

[rileyp]

I wouldn't worry about buying These CB under the new regs they would be allowed to be installed.

please explain?
I just put 10 of them in a hospital about 3 months ago for mechanical services.
Those breakers are everywhere!

[another termite]

As far as i know you can still use them though in domestic you must provide a seperate RCD for power and lighting circuits (which looks like is there). We use those "quicklag" puppies all the time in industrial jobs and they last forever and normally fit quick and easily into a DB with a buss bar system.

[nev25]

please explain?

Went to an info session on thee the new AS/NZ3000/2007 Regulations the other night
And we where told every circuit mush have its own RCD
We can no longer protect many circuits with one RCD