#ph low voltage with load

[Khewell]

We installed a 3ph transformer 480v to 208.
this runs from a 480 bus to the transformer to a 208 breaker panel.
With the main on the panel off we measure 108v ( wire to ground) and 207 across legs all 3 good.
With the main breaker on we measure the same.
turn on any breaker and the voltage measured leg to ground measures 158 - 198v, except 1 leg measures 14.6v
across the legs and I get 207v.
no netural installed..
got no ideal I'v been over this ane over this.

 

[ptonsparky]

You need to bond the secondary neutral.

We bring it out to the first disconnect and bond it there with an EG going back to the transformer.

 

[Khewell]

You need to bond the secondary neutral.

We bring it out to the first disconnect and bond it there with an EG going back to the transformer.

Thanks for the help that got us going.

 

[LarryFine]

You need to bond the secondary neutral.

 

[ActionDave]

You need to bond the secondary neutral.

We bring it out to the first disconnect and bond it there with an EG going back to the transformer.

You are only the third person I know of that bonds in the first disconnect. The other two are me and my first journeyman.

 

[don_resqcapt19]

You need to bond the secondary neutral.

We bring it out to the first disconnect and bond it there with an EG going back to the transformer.

It is a supply side bonding jumper and not an EGC. If you are installing an EGC, it will be smaller than the required supply side bonding jumper.

 

[ptonsparky]

It is a supply side bonding jumper and not an EGC. If you are installing an EGC, it will be smaller than the required supply side bonding jumper.

I stand corrected.