Does a transformer provide transient protection?
A. No. A transformer does not stop high frequency transients like lightning. A typical lightning transient is several hundred micro-seconds in duration. This is so fast that it jumps thru the inter-winding capacitance of the transformer and appears on the secondary at about the same amplitude as before the transformer. Thus it is necessary to provide protection on the low voltage side as well as the high voltage side of the transformer. For example, if the transient voltage is limited to 800 volts peak on the 460 volt primary side, it will also appear as 800 volts on the 120 volt secondary side. This 800 volts is too high for 120 volt equipment and must be limited to 200-250 volts by another TVSS rated for operation on 120 volt systems. Q. What about other types of power conditioners, constant voltage transformers, series filters, etc. A. Each type of power conditioner has some specific purpose usually associated with regulating the steady state voltage, but NOTHING stops transients be
