if CT is connected to the dedicated analogue input of protection terminal, protection works properly, but if there is an electrical sum of some different CTs and a single relay, i suppose that differential protection can fail, because part of differential current will flow through the...
For relay protection it is better to use higher CT ratio than for metering.
Protection CT core (TPX, TPY, TPZ) has to work properly in case of short-circuit conditions.
Metering core has to work properly only in case of normal load condition.
In addition, if you want to choose CT to prevent...
