A PT’s secondary winding should never be short-circuited, since Short-circuiting a PT’s secondary winding may result in a dangerous amount of current developing in the circuit because the PT will attempt to maintain a substantial voltage across a very low resistance.
Also see: Why CT secondary winding should never be open-circuited
While the recommendation to never short-circuit the output of a PT makes perfect sense to any student of electricity or electronics who has been drilled never to short-circuit a battery or a laboratory power supply.
Reference and complete PDF article: Short Handbook on Instrument Transformers Safety
Related Downloads:
- Potential Transformers Handbook
- Current Transformers Handbook
- Transformer Polarity Handbook
- Short Handbook on Instrument Transformers Safety