Connectors in Bushing in a Power Transformer

[LabhitaUB1]

I had few general question for all power transformer bushings.

1. When we a buy a power transformer, the bushings that come along with it, does it contains connectors (top connector that connects the bushing to the power bus and bottom connector to the transformer) or the connector parts come separately?
2. When we replace a bushing with a different manufacturer, do we need to replace the connector?
3. the description that comes in the drawing of the transformer mentions connectors as "HV Bushing Connector" or "LV Bushing Connector". My question is this connector goes on the bottom of the bushing or on top of it.?
4. Also, we are trying to use PCORE test terminals in all our bushings. my questions is do I still need to use top connector in addition to the testing terminal?

Any help is highly appreciated.
Thanks

 

[prc]

1) No. Normally both top and bottom connectors are not included with bushing. Only connecting pads are provided on the bushings.

2) This depends on the connecting pad of the replaced bushing. In most of the countries/some utilities these are standandardised. Then there is no problem.

3) It means top connector.Please have a close look of the drawing. Sometimes connector means only connecting pad.

4) Hope Pcore test terminal means the test tap provided - the connection from the outermost conducting layer of condenser core to earth. For insulation power factor measurement, both top terminal and test terminal are required.

 

[rterickson]

If you are still at the specification stage, you can get what you want, just put it in your spec. For example, if you specify 4-hole tinned bronze connectors on all bushing terminals, you can go ahead and design your substation connections well in advance.

If the transformer is already on order, carefully review the manufacturer's drawings, bushing drawings, and parts lists for hints as to the connections you will need to make on site.

Most bushings come with bronze studs, so you will need to know the diameter and threads per inch to specify your terminals, plus connectors for copper or aluminum conductor or bus, bolted or compression, etc.

 

[froesen]

prc, I believe he's referring to these devices. Makes testing a heck of a lot easier than if you're using mechanical connectors.

 

[stevenal]

Link

Looks like the device replaces the normal stud to pad connector. More places for potential hot spots.