Reversed Transformer

[ramsy]

The former. I believe it's cut off on the left.

Yes, blue phased service entrance cable must land on same core (missing H3) Left of X1 label.

H3 & X1 on same core may be correct for split-phase delta's, or another critical error for such high-leg transformers

 

[jim dungar]

H3 & X1 on same core may be correct for split-phase delta's, or another critical error for such high-leg transformers

I have no idea what you are trying to say.

There is clearly only one core assembly in this transformer. Are you trying to say that a specific HV winding is mounted outside of a specific LV winding on the same leg of the core?
The specific HV and LV pairing would be shown in the schematic on the nameplate.

 

[ramsy]

I have no idea what you are trying to say.

No offense taken

There is clearly only one core assembly in this transformer.

Thank you for pointing out improper nomenclature

Are you trying to say that a specific HV winding is mounted outside of a specific LV winding on the same leg of the core?

Lets try your term "winding," rather than "core."

The specific HV and LV pairing would be shown in the schematic on the nameplate.

Since nameplate schematic shows no split phase, is the labeling H3 and X1 on same winding incorrect ?

 

[don_resqcapt19]

I’ve never seen 480 delta. Is there a wild leg in this configuration?

There is a 4-wire 480 volt delta...with one coil center tapped and grounded. Line to line is 480, line to neutral on two phases is 240, and on the third 277. Not a very common installation, but it does exist. Sometimes it is just used to get a grounded system that is not 480 volt to ground like a corner grounded system.

 

[don_resqcapt19]

Since nameplate schematic shows no split phase, is the labeling H3 and X1 on same winding incorrect ?

I don't understand. X1 would be on a secondary winding and H3 on a primary winding.

 

[jim dungar]

Since nameplate schematic shows no split phase, is the labeling H3 and X1 on same core winding incorrect ?

H3 and X1 are terminal numbers only.
The winding that contains the connection for the terminal H3 also has a connection to H1, per the nameplate diagram. This winding is at the high L-L voltage for this transformer. Its low voltage companion winding contains the connection to terminal X1. The other end of this LV winding is connected to X0.
The is no 'split phase' in this transformer.

 

[ramsy]

H3 and X1 are terminal numbers only.
The winding that contains the connection for the terminal H3 also has a connection to H1, per the nameplate diagram. This winding is at the high L-L voltage for this transformer. Its low voltage companion winding contains the connection to terminal X1. The other end of this LV winding is connected to X0.
The is no 'split phase' in this transformer.

Ok, starting to see labels & jumpers matching diagram in Post 1.

Also see xfmr wired as step down:
* Service-entrance cable to "H" lugs, with black jumpers connecting all 3 Delta windings, is the primary
* Feeder cable to "X" lugs, emerge from WYE windings joined at XO bus, as the secondary

 

[jim dungar]

Also see xfmr wired as step down:

Per the OP thus has been wired as a step up transformer.

How are you identifying service entrance cable vs feeder?

It would not be possible, per the NEC, to have service conductors terminated directly on a customer owned transformer.

 

[ramsy]

How are you identifying service entrance cable vs feeder?

Emerging from right side of enclosure, a 3-conductor SE Cable with concentric sheath appears twisted in green tape and terminated to X0.

 

[jim dungar]

Emerging from right side of enclosure, a 3-conductor SE Cable with concentric sheath appears twisted in green tape and terminated to X0.

But it is a feeder.

 

[ramsy]

But it is a feeder.

Are feeders allowed to use bare ground wire ?

 

[ramsy]

But it is a feeder.

You are correct,

xfmr is wired step up:

OP clarified in Post 19 charred wire on XO feeds the transformer

It's the EGC that the original installer connected from XO to the cabinet feeding the trans.
The other green wire on the right goes to the bonding bar via ser cable to a 3 phase only panel.

While SER is correct observation on my part, that cable is a feeder with bare EGC.

 

[ActionDave]

While SER is correct observation on my part, that cable is a feeder with bare EGC.

A wire type EGC is allowed to be bare.

 

[hillbilly1]

A wire type EGC is allowed to be bare.

There are some instances where it is required to be insulated, but this is not one of them.

 

[kwired]

There is a 4-wire 480 volt delta...with one coil center tapped and grounded. Line to line is 480, line to neutral on two phases is 240, and on the third 277. Not a very common installation, but it does exist. Sometimes it is just used to get a grounded system that is not 480 volt to ground like a corner grounded system.

High leg to neutral is 416 not 277.