An electromagnetic device comprises an enclosure, at least one winding in the interior of the enclosure, at least one wireless sensor attached to the winding for sensing at least one property or deficiency of the electromagnetic device and at least one active communication unit comprising transceiving circuitry and at least one antenna, wherein the transceiving circuitry is placed on the exterior of the enclosure and the least one antenna is placed inside the enclosure for communication with the at least one sensor, wherein the at least one sensor comprises at least one sensor attached to the winding, and wherein the at least one sensor attached to the winding is a printed electronic sensor comprising electronics printed on an insulating substrate, where the substrate faces the at least one winding.