3 phase test readings help

[R-fur]

Bradly
There are two main possibilitys, If it is rural and fed off its own pole mounted transformer it could be a split phase supply where the transformer is HV to 500V with a center tap giving 250V between each end to the center neutral tap and 500V between the outers.
If it is in a town it may be fed off an old DC cable which has been converted to two phase and neutral.
A third option is that it is a cable fault with an open circuit/weld.

 

[Lucien Nunes]

The voltage measured between the lines (450V) suggests a split-phase 230-0-230 supply rather than two phases out of a 3-phase 400/230V system.

A look at the meter(s) will confirm as they will have the appropriate spec for the supply in use. Also, if the HV feeding the transformer is single-phase (with two lines only) then the LV service must be split-phase.

If you are only connecting single-phase loads, then you can follow normal practice. If this is the main DB with one outer shared between the L1 & L2 ways, the total load load on those should probably equal the load on the L3 ways.

 

[Bradley6969]

The voltage measured between the lines (450V) suggests a split-phase 230-0-230 supply rather than two phases out of a 3-phase 400/230V system.

A look at the meter(s) will confirm as they will have the appropriate spec for the supply in use. Also, if the HV feeding the transformer is single-phase (with two lines only) then the LV service must be split-phase.

If you are only connecting single-phase loads, then you can follow normal practice. If this is the main DB with one outer shared between the L1 & L2 ways, the total load load on those should probably equal the load on the L3 ways.

Hi thanks, I have some double pole switches and single pole so just connect as normal?

I also have a 3 phase pool to wire up so I’m not sure how that’s going to work yet

 

[Bradley6969]

Have you any actual 3 phase or multi phase loads that need supplying?

Hi I have double pole switches eg 2 lives from there and then just single pole MCBS

Have pool to do which is 3 phase but I’m not sure what needs to be done with thay

 

[Pete999]

Hi I have double pole switches eg 2 lives from there and then just single pole MCBS

Have pool to do which is 3 phase but I’m not sure what needs to be done with thay

Make sure you get the phase sequence the right way around Mate otherwise when you empty the pool the dain water will go in a different way than normal.

 

[Strima]

I also have a 3 phase pool to wire up so I’m not sure how that’s going to work yet

The pool will work fine, the pumps however are a different story.

You need to confirm if you have two or three phases otherwise it’s going to start getting expensive.

 

[Bradley6969]

Make sure you get the phase sequence the right way around Mate otherwise when you empty the pool the dain water will go in a different way than normal.[/QUO
Thanks so single phase circuits all good? Just the pool I’m sure there getting an extra phase so need to confirm

 

[Bradley6969]

The pool will work fine, the pumps however are a different story.

You need to confirm if you have two or three phases otherwise it’s going to start getting expensive.

Well I have split phase supply all my outgoing circuits are either single pole or the use of 2 phases eg black and brown from a 2 pole MCB so there all fine just the one pool

 

[Charlie_]

Are you not working to any plans or specifications?

 

[Bradley6969]

Are you not working to any plans or specifications?

Yes but contractor has quoted saying there’s 3 phase when there’s not

 

[Bradley6969]

So my single pole and double pole with all be ok?

 

[Bradley6969]

it’s only temporary till they sort supply out

 

[Charlie_]

Work to the plans and specifications and don’t deviate from it unless you have revisions..

 

[Pete999]

Yes but contractor has quoted saying there’s 3 phase when there’s not

Best put him right then Mate. Otherwise it could be your gonads being hung out to dry, when it all goes Mamery's up.

 

[davesparks]

I also have a 3 phase pool to wire up so I’m not sure how that’s going to work yet

It won't work, don't connect a three phase load to this supply, it won't work and may damage it.

 

[Strima]

Well I have split phase supply all my outgoing circuits are either single pole or the use of 2 phases eg black and brown from a 2 pole MCB so there all fine just the one pool

It sounds very much like you don't have a three phase supply so connecting three phase equipment is not advisable as it will not work correctly and worst case it could be damaged which will get expensive.