Isolation Transformer IG Connection

[infinity]

Take a look at this schematic for an isolation transformer. Does the grounding setup meet the NEC? The current setup has all of those ground connections terminating on the XO and a bonding jumper going to the transformer case.

 

[benaround]

Rob, I don't see a problem with it.

 

[cadpoint]

OK, can you explain the neutral lift of "F" ?

 

[ty]

Typically, the 'NEUTRAL' would be shown with a line drawn from the center of the 'Y', not to the 'Ground Electrode', Electrically it is the same, but not how it is typically drawn.

The 'Neutral Lift' on F, is just showing the Neutral and Isolated Ground not bonded to the Equipment groundon the secondary?

 

[cadpoint]

Typically, the 'NEUTRAL' would be shown with a line drawn from the center of the 'Y', not to the 'Ground Electrode', Electrically it is the same, but not how it is typically drawn.

The 'Neutral Lift' on F, is just showing the Neutral and Isolated Ground not bonded to the Equipment groundon the secondary?

Then it's a bad Drawing! And is a Basic Code Violation! Get this, As Drawn!

 

[infinity]

The "F" is part of the drawing that got truncated. It actually was the word "Removable" for removable links.

I should mention that the "current setup" is what is actually installed but this drawing is what they really want.

 

[ty]

Then it's a bad Drawing! And is a Basic Code Violation! Get this, As Drawn!

??????? !!

 

[SG-1]

The only odd thing I notice about the SDS grounding & bonding is that there is no discernible system bonding jumper.

Is the Main Service ungrounded ?

 

[infinity]

The only odd thing I notice about the SDS grounding & bonding is that there is no discernible system bonding jumper.

Is the Main Service ungrounded ?

Nope, the main service is 277/480. My guess is that it was simply drawn that way to show the feeder for the primary without a neutral. This drawing is from an audio consultant for a transformer feeding sound equipment receptacles.

The question here is would the setup depicted in the drawing be any different electrically than if all of the terminations were at the XO with a bonding jumper to the case instead of all of the conductors terminating at a single point on the transformer case as shown?
.

 

[don_resqcapt19]

...
The question here is would the setup depicted in the drawing be any different electrically than if all of the terminations were at the XO with a bonding jumper to the case instead of all of the conductors terminating at a single point on the transformer case as shown?
.

I don't see where there would be any electrical difference. How are all of the conductors terminated at the single point on the case?

 

[ty]

This drawing is from an audio consultant for a transformer feeding sound equipment receptacles.

well there's your problem

The question here is would the setup depicted in the drawing be any different electrically than if all of the terminations were at the XO with a bonding jumper to the case instead of all of the conductors terminating at a single point on the transformer case as shown?
.

I don't think so.

 

[cadpoint]

Were reaaly talking about a lot of things

Section VI 250.110

​

But where also talking about this MH neutral 100 definations from ECM

I'm sorry I don't get the implied sepation on these two circuit lines, anything smart yes SDS or whatever otherwise no.

I can only recall a code but can't remember which one that if your going to switch the neutral you switch everything at once.

95% of electrician will never see that or use that, I just think its scarey to imply something that bad.
A box of rocks I might be, but that sybolism leaves a whole lot to be desired!

 

[ty]

I must have missed something?
Where are we switching the Neutral??

 

[infinity]

I don't see where there would be any electrical difference. How are all of the conductors terminated at the single point on the case?

That would require a small piece of bus bar with the appropriate sized lugs installed and bolted to the transformer case. IMO it's no different electrically than landing everything on the XO with a bonding jumper to the can.

 

[SG-1]

The "F" is part of the drawing that got truncated. It actually was the word "Removable" for removable links. QUOTE]

I think he is refering to the removable links.

I agree electrically everything required to be grounded & bonded are.

 

[infinity]

The "F" is part of the drawing that got truncated. It actually was the word "Removable" for removable links. QUOTE]

I think he is refering to the removable links.

I agree electrically everything required to be grounded & bonded are.

Yes, that's what those pieces are in the bottom right of the drawing. Removable links for the neutral and IG conductors. The previous guy didn't install them as he debated that they serve no real purpose.

 

[steve66]

I can only recall a code but can't remember which one that if your going to switch the neutral you switch everything at once.

I must have missed something?
Where are we switching the Neutral??

The removable links worry me too. Why would you want a removable link in the neutral or ground connection? Is that something the audio guy added to the drawing? Is the audio guy going to remove these if he has ground noise in the audio system? Maybe he thinks he will remove these and then ground the system elsewhere.

Yes, that's what those pieces are in the bottom right of the drawing. Removable links for the neutral and IG conductors. The previous guy didn't install them as he debated that they serve no real purpose.

I think maybe the previous guy might have had the right idea. Not installing them might keep the audio guy from removing a required ground connection.

steve