Pad mount transformers

[giselle]

I have a stupid question: How do you define a "pad mount" transformer? I thought it was related to the fact that it is mounted on a pad however I am getting a sense that it relates the the connections. Please clarify.

 

[SphincterBoy]

You are correct. The term padmount opens up a whole new set of terms and definitions relating to underground power distribution.

The terms are:

dead-front primary connections (no exposed high-voltage parts, to accommodate rubber 'elbows', with no bushings. Very popular for safety reasons.

live-front: exposed live metal connections to standard primary bushings--we never use these.......deadly.

radial fed primary: high-voltage lines terminate on a single bushing or connection, with no other connection to feed more transformers or circuits.

loop fed: high voltage lines terminate at a connection, with an additional termination to feed additional transformers or circuits at other locations. This is very popular, and the primary purpose of this is in case one of the two primary lines fail, it can be disconnected (for repair) and the transformer can be fed from the other line connected at this point, from another circuit.

The padmounted transformers typically have two separate compartments: a high-voltage primary compartment, and a low-voltage secondary compartment.

You can obtain much more information from ANSI C57 (transformers), as well as rubber elbow manufacturers Elastimold and Cooper Power Systems RTE.

I'm sure I missed a few things, but this is fairly quick and to-the-point summary.

 

[rbulsara]

Pad mounted only defines that it is mounted on a pad. All other features still need to be selected to suit the requirement, including they type of connections. There a multitude of options and features available for connections, cooling, sensors, protection, winding, ratings etc. and all of them have to be defined further in a specification to get the right unit.

 

[stevenal]

From IEEE 100:

pad-mounted transformer (power and distribution transformers)
An outdoor transformer utilized as part of an underground
distribution system, with enclosed compartment(s)
for high-voltage and low-voltage cables entering from below,
and mounted on a foundation pad.

So putting an overhead can on a concrete pad does not change it into a pad-mount.

 

[alehman]

http://www.abb.com/Product/seitp321...8800461d47.aspx?productLanguage=us&country=US