Double Pole Voltage Transformer - Marshalling Box Wiring Diagram

[mikeangel]

Hi everyone!

Could someone please be so kind and provide a marshalling box wiring diagram for this situation particular situation where I've to 2 double pole voltage transformer with two secondary windings in a 15kV 3-phase busbar.

Thank you in advanced.

 

[waross]

A picture will help.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[mikeangel]

Yes waross, tomorrow I will upload what I have. Thank you.

 

[mikeangel]

Dear all,

I've upload the elements that i've.
(part 1of2)

Regards

 

[mikeangel]

(part 2of2)

 

[waross]

Hello mikeangel;
Do you follow North American standards or European standards?
General comments:
Marshalling cabimet:-
Physical characteristics;
The cabinet must be suitable for the location, ie: indoors or outdoors. The codes will specify a type for the intended location.
Size: The cabinet should have adequate working space for the installed terminal strips. Some code may specify minimum clearances to cabinet walls and to adjacent terminal strips.
Company engineering standards may address marshalling cabinet size.
Wiring; preferred method. Use an incoming terminal strip(s) with a terminal for each incoming conductor and an outgoing terminal strip(s) with a terminal for each outgoing wire.
Install interconnecting conductors and jumpers as needed.
Wiring; Economy method, not recommended.
A single terminal strip(s) may be used for both incoming and outgoing conductors with interconnections and jumpers installed on the terminal strip(s).
Transformer:
In North America we would call that a Potential Transformer. It is in the class of instrument transformers that includes Current Transformers. eg: PTs and CTs
The transformer would also be described as having two primary bushings and/or suitable for line to line connection.
Additionally, it would be described as having two secondary windings.
Tell us what code that you work under and someone with specific knowledge will probably help with further suggestions.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[mikeangel]

Thank you waross for your suggestions and advices. My major problem is in the drawing of the marshalling box wiring diagram, because I never see this kind of arragement/assembly, ie, using two double-pole voltage/potential transformer with two secondary cores in a 3phase system. I'm working under the IEC codes in Europe.

Thank you again.

 

[DTR2011]

The 2 transformer connection is called "Open Delta" in the ANSI world. NOT to be confused with what is called "Open Delta" in IEC world. On the primary side, 1 PT is connected A-B and one C-B, with the non-polarity sides of the PT connected to B Phase.

Once you understand the difference, all secondary connections should be straightforward. The "B" phase on the secondary side is grounded.

 

[mikeangel]

I came with the attached wiring diagram for the marshalling box. What do you think? It is ok?
Thank you

 

[waross]

I wonder about Q1 and Q2.
Do you really want disconnect switches in protection and control circuits?

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[mikeangel]

waross, it is usual in our client substations to install MCB in these circuits.

 

[mikeangel]

But the wiring diagram is ok?