Protection Engineering Basics and Schemes Protection Engineering | Page 44

On any nameplate standard must be mention, ratio of PT
is also mention, burden of PT is mention which is usually
greater then CT up to 400VA I seen, also net standard
voltage is mention, net standard voltage is primary
voltage on which PT is applied, highest standard voltage is
the voltage application validity means up to which level of
primary voltage it can be applied, class show the metering
or protection application level. Insulation level voltages
are mention same the first one is insulation and second
one is impulse voltage , frequency must mention , and
most important is the voltage factor , voltage factor
pg. 44