Outdoor Current Transformers are cast resin insulated. Primary winding as well as the core(s) with secondary winding moulded in one single process with epoxy resin which has been processed under vacuum. The secondary terminals are located in a sturdy terminal box made of cast aluminum. For metering transformers, this terminal box can be sealable. Primary terminals are optionally inserts, bolts, terminal pads, or clamp-type connectors.