Standby generator

[g-davies]

We have some work to do at a large house in the countryside,that has a two phase supply installed .There is a standby generator being fitted next week,which requires conversion from three phase into two phase,by the generator suppliers.Does anyone know if we need two neutral cables to feed the house,or is it just like three phase without phase three.We have been told their is a 480 potential between the two phases,and not the normal 415.

 

[chilliwilly]

No just one neutral, the gen specialist will sort that for you. How come you need a genny anyway? And is this in the UK or North America?

 

[shanky887614]

mate.

think star/delta

you shouldnt have 2 neutrels.

the genny will only have 1 neutrel so why are you asking?

 

[g-davies]

Thanks,thought this was the case,but as we are running in a cable from the gunny I thought we had best make sure of how many cores we needed.We are in the uk by the way,the house north of Preston,up in the hills.

 

[g-davies]

Thanks ,I thought that was the case.We are running a cable in from the gunny so I was making sure it had enough cores in it.

 

[Marvo]

We have some work to do at a large house in the countryside,that has a two phase supply installed .There is a standby generator being fitted next week,which requires conversion from three phase into two phase,by the generator suppliers.Does anyone know if we need two neutral cables to feed the house,or is it just like three phase without phase three.We have been told their is a 480 potential between the two phases,and not the normal 415.

This is a 180° split phase system. The two phase are 180° apart rather than the usual 120° on the standard supplies. It's quite unusual to find these supplies nowadays, we've encountered a few over the years usually out in the middle of nowhere.


I hope the generator specialists have been informed it's a 180° split phase system that their generator's going onto. Also be aware that many MCB's and other switchgear isn't rated for the higher phase to phase voltage so take care when choosing your protection devices and switches etc.

 

[Knobhead]

I hope the generator manufacturer haven’t been told its 180° split phase. You’ll get no output between phases. You would between phase and neutral but the neutral conductor would need to be 2X the phases.
It will be centre tapped, the winding at 0° shift.

 

[Knobhead]

I also hope you’re going to fit the correct change over for the DNO and generator supplies. Otherwise there’s going to be trouble with the DNO.