[Linked Image from 6l6.net]

Here is a typical illustration of a shorting-block pole. [http://www.marathonsp.com/MSP%20CATALOG/2005%20Catalog%20pdfs/1500%20Series.pdf]

For multi-ratio (tapped) CTs, only two pins need shorting to prevent high open-circuit voltages across an open secondary. Be careful, though, not to lift the ground connections {typically X1} to prevent high electrostatically induced voltage from secondary to ground with energized equipment..

Also, besides no overcurrent-relay operation from left-in-place shorting pins, any sort of comparison-, unbalance- or differential-relay scheme can falsetrip during 'normal' operation.


[This message has been edited by Bjarney (edited 11-23-2005).]