3 phase test readings help

[Bradley6969]

Hi have wierd dilemma, looks to be 3 phase - 4 wire system so testing am getting this
L1-L2 Nothing
L2-L3 450v
L1-L3 450v
L1-N 230v
L2-N 230v
L3-N 230v
Why no L1-L2?

 

[Strima]

They're on the same phase.

 

[Bobster]

Correct, it's not a true 3 phase supply.

L1 and L2 have the same phase angle.

 

[buzzlightyear]

They're on the same phase

DRAT STRIM ,BEAT ME TO IT .

 

[westward10]

Your line to line voltage indicates you may have a split phase supply and the fact there is 0v between L1 and L2 points to them being on the same phase.

 

[Bradley6969]

Yes got it guys thanks just realised haha

 

[buzzlightyear]

Yes got it guys thanks just realised

we have all been their Bradley scratching your head thinking now how do this three phase work ,lol.
back to school you need to go .

 

[Charlie_]

I was called out a few years ago to a faulty compressor..
Spoke to the sparky on site who confirmed all was ok, voltages checked, fuses ok, etc..
One of the fuses to the compressor had blown, L1 going through winding and back up onto L2 fuse..
said he had checked both sides of fuses and they were all live, he scratched his head for a while, drew him the circuit and the penny dropped...
I put it down to a faulty overload, saved him his blushes

 

[Bradley6969]

Thanks guys so I have some outgoing circuits to connect up, so I just balance the load between L1 and L3 it’s only temporary till they get supply sorted sorry only apprentice

 

[Bobster]

Balance the load across all 3, the DNO have provided this set up for a reason.

Also, if you are an apprentice, who is supervising you?

 

[Bradley6969]

Balance the load across all 3, the DNO have provided this set up for a reason.

Also, if you are an apprentice, who is supervising you?

But L1-L2 are on the same phase? And I’m with a couple of guys just thought I’d ask saves me looking stupid

 

[Charlie_]

At what position in the installation are you doing your tests?
It needs to be right at the incomer on the supply side with the load side isolated

 

[Bradley6969]

At what position in the installation are you doing your tests?
It needs to be right at the incomer on the supply side with the load side isolated

Done at the very point the supply’s income is connected all fuses disconnect

 

[Charlie_]

So to confirm; with everything isolated you had two common phases?

 

[Bobster]

Have you asked the experienced guys what they think, have they done or supervised any of this testing?

You should apply for the trainee part of the forum if you are an apprentice, that way answers are tailored better suited for someone who is learning. Will also get less grief for asking what would be a silly question for someone experienced.

 

[Bradley6969]

So to confirm; with everything isolated you had two common phases?

Yes correct and where transformer is on top of the pole there 2 fuses not sure what there called and then one cable tapped into the other what looks like

 

[Bradley6969]

You should apply for the trainee part of the forum if you are an apprentice, that way answers are tailored better suited for someone who is learning. Will also get less grief for asking what would be a silly question for someone experienced.[/QUOTE]
Well there on the same site but doing other bits so thought I’d ask so I kind of know what I’m talking about

 

[Charlie_]

What apprentice year are you?
Don’t ever hesitate asking questions, it’s the best way to learn and also it shows to your colleagues that you are interested and keen to learn

 

[Bradley6969]

Only 2nd year and I know just like to show I kind of know what I’m looking for and at
L1-L2 Nothing
L2-L3 450v
L1-L3 450v
L1-N 230v
L2-N 230v
L3-N 230v

So if I connect all sub circuits the same then there should be no issues?

 

[Bobster]

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