Meramec Instrument Transformer Co

Encapsulated Bushing-Type Generator Current Transformer

Application:

The Encapsulated Generator CT is designed to be mounted over the high voltage terminal bushing of power generators. When properly installed, the EGCT can be used in Isolated Phase Bus (IPB) enclosures on higher system voltage levels while maintaining its own mere 600 Volt class rating. Its simple construction provides a low leakage product with extremely high short circuit capabilities. Because the coil is totally encapsulated it is ideal for harsh and hazardous environments.

Construction:

The toroidal core is continuously tape wound using cold rolled grain oriented electrical grade silicon steel, which receives a full stress relief anneal after it is wound to its specified dimensions. The insulation used provides a durable 130°C (Class B) system throughout the entire coil assembly. The secondary winding is wound of insulated copper magnet wire over the fully insulated core with the turns equally spaced around the core periphery. Specially engineered shield windings which are strategically integrated into the main secondary winding to minimize the affects of stray magnetic flux from adjacent high current conductors. The outer insulation is a molded resin rated for outdoor use. All mounting hole features are cast-in aluminum hubs which prevents mounting hardware from coming in direct contact with the resin surface. It will endure rigorous vibration and is impervious to moisture.

Connections:

The primary polarity H1/P1 is an embossed dot into the resin surface. The secondary terminals are ¼-20 silicone bronze studs provided with hex nuts and cupped washers for positive compression to assure long lasting connections. Terminal identification is permanently engraved with dual designations “X” and “S” for compatibility in the global market. The X1/S1 terminal represents the instantaneous polarity reference with respect to H1/P1 and will be identified by a colored dot. A cast aluminum conduit box with (2) 1” NPT hubs and blanking plugs is provided with a removable cover. The size of the box allows for adequate passing of wires from adjacent phases. Other hub openings are available.