A current transformer (CT) is an electric device that produces an Alternating_current (AC) in its secondary which is proportional to the AC in its primary.Here is 5A in Primary and 5mA in secondary.
Typically used for relay protection and energy meter
Burden Resistance:50 Ohm
Insulation Resistance:100M ohm@500Vdc
Dielectric strength: 3000V r.m.s (2mA @ 1minutes)