SSBJ vs Grounded Conductor

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quantum

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These are my assumptions; are they correct?
  • Cable from Utility Transformer to a Service Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor, and an SSBJ (If utilizing 480/277V downstream)
  • Cable from Utility Transformer to a Service Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor (If utilizing only 480V downstream)
  • Cable from a Distribution Transformer to a Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor, SSBJ (If utilizing 480/277V downstream)
  • Cable from a Distribution Transformer to a Disconnect Switch - 480/277V Secondary - A, B, C, SSBJ (If utilizing 480V downstream)
I'm wanting to make sure I correctly understand when the grounded conductor is truly a grounded conductor (taped white) or is actually the ssbj (taped green).
 
Why the two different scenarios with service disconnects and just disconnects?
 
Supply side bonding jumpers are not installed between the utility transformer and the service equipment.

In all cases, if the utility is supplying a grounded system, there will be a grounded (white) conductor run to the service equipment. This applies even were there are no line to neutral loads.

Supply side bonding jumpers are always required on the secondary side of a SDS.

In the case of an SDS that is not supplying line to neutral loads, you can omit the grounded (white) conductor and install a supply side bonding jumper between the transformer and the first disconnect. The supply side bonding jumper is permitted to be green but not required to be.
 
quantum said:
I'm wanting to make sure I correctly understand when the grounded conductor is truly a grounded conductor (taped white) or is actually the ssbj (taped green).
Click to expand...
In my opinion, there should be no green wire (except perhaps for any local electrodes) on the service side of the main disconnect.

The premises equipment grounding system begins there, and "the" bonding jumper is whatever connects white and green together.
 
don_resqcapt19 said:
Supply side bonding jumpers are not installed between the utility transformer and the service equipment.

In all cases, if the utility is supplying a grounded system, there will be a grounded (white) conductor run to the service equipment. This applies even were there are no line to neutral loads.

Supply side bonding jumpers are always required on the secondary side of a SDS.

In the case of an SDS that is not supplying line to neutral loads, you can omit the grounded (white) conductor and install a supply side bonding jumper between the transformer and the first disconnect. The supply side bonding jumper is permitted to be green but not required to be.
Click to expand...

So based on that statement, I see my error, and when I originally typed this up I did not have the SSBJ on the first item below and should not have included it. I stand corrected, this should be correct now?
  • Cable from Utility Transformer to a Service Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor (If utilizing 480/277V downstream)
  • Cable from Utility Transformer to a Service Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor (If utilizing only 480V downstream)
  • Cable from a Distribution Transformer to a Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor, SSBJ (If utilizing 480/277V downstream)
  • Cable from a Distribution Transformer to a Disconnect Switch - 480/277V Secondary - A, B, C, SSBJ (If utilizing 480V downstream)
On a previous project, me and the electrical inspector were trying to decide if the grounded conductor would be phased green or white (scenario 2 above).
 
infinity said:
Why the two different scenarios with service disconnects and just disconnects?
Click to expand...
In one instance the transformer is utility/customer owned and the conductors are service conductors. In the other scenario the transformer is not a utility/customer transformer and the disconnect is just an equipment disconnect.
 
quantum said:
So based on that statement, I see my error, and when I originally typed this up I did not have the SSBJ on the first item below and should not have included it. I stand corrected, this should be correct now?
  • Cable from Utility Transformer to a Service Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor (If utilizing 480/277V downstream)
  • Cable from Utility Transformer to a Service Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor (If utilizing only 480V downstream)
  • Cable from a Distribution Transformer to a Disconnect Switch - 480/277V Secondary - A, B, C, Grounded Conductor, SSBJ (If utilizing 480/277V downstream)
  • Cable from a Distribution Transformer to a Disconnect Switch - 480/277V Secondary - A, B, C, SSBJ (If utilizing 480V downstream)
On a previous project, me and the electrical inspector were trying to decide if the grounded conductor would be phased green or white (scenario 2 above).
Click to expand...
If the system bonding jumper is at the first disconnect there will be a white conductor between the transformer and the disconnect, even where there are no line to neutral loads. There will also be a SSBJ.
 
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