Tulsa Electrician
Senior Member
- Location
- Tulsa
- Occupation
- Electrician
I was sent these pics and was ask my thoughts. I responded above my pay grade.
Thought I would post and learn something from this.
What I know:
13.2kv feeding this wye wye transformer,480 secondary.
13.2 feed from ats.
Service point is 13.2 with primary metering.
Feeder to ats from service disc 13.2
Load breaks elbows not grounded just tapped off.
There is a MV tap box between the generator ats and the transformer.
In the tap box the MV shields are tapped off as well. The gray thhn tied together with no bonding to the RMC or the metal enclosure. There is a driven rod electrode and hooked to nothing.
HO and XO bonded together in transformer
15 kv cable no concentric netural shield only.
Gray 4/0 thhn in RMC with 4/0 MV cables.
Bonding bushings on RMC
Gray tied to ground rod and transformer case.
I ask why the gray and was told it's a neutral.
I thought this should be EGC or SSBJ and bonded to raceway since it's a feeder. Or at least bond the RMC to the case and rod electrode.
I would also thought if it's a neutral why not run a concentric neutral MV cable.
Why is the shield left ungrounded? Is this normal
Not 100% sure was told it's a wye distribution from utility.
Thought I would post and learn something from this.
What I know:
13.2kv feeding this wye wye transformer,480 secondary.
13.2 feed from ats.
Service point is 13.2 with primary metering.
Feeder to ats from service disc 13.2
Load breaks elbows not grounded just tapped off.
There is a MV tap box between the generator ats and the transformer.
In the tap box the MV shields are tapped off as well. The gray thhn tied together with no bonding to the RMC or the metal enclosure. There is a driven rod electrode and hooked to nothing.
HO and XO bonded together in transformer
15 kv cable no concentric netural shield only.
Gray 4/0 thhn in RMC with 4/0 MV cables.
Bonding bushings on RMC
Gray tied to ground rod and transformer case.
I ask why the gray and was told it's a neutral.
I thought this should be EGC or SSBJ and bonded to raceway since it's a feeder. Or at least bond the RMC to the case and rod electrode.
I would also thought if it's a neutral why not run a concentric neutral MV cable.
Why is the shield left ungrounded? Is this normal
Not 100% sure was told it's a wye distribution from utility.
