Meramec Instrument Transformer Co

Outdoor Mounted Slip-Over Bushing Current Transformer

Application:

The Outdoor Mounted Slip-Over Bushing Current Transformer is self contained and designed to be mounted externally over the high voltage terminal bushing of power transformers, power circuit breakers and cable terminators (potheads). In most cases the slip-over BCT, with its ease of installation, is a reliable and economical solution when upgrading system protection and adding additional metering points. When properly installed, the slip-over BCT can be used on higher system voltage levels while maintaining its own mere 600 Volt class rating. Its simple construction provides a low leakage product with virtually unlimited short circuit capabilities, far surpassing its stand alone wound-type counterpart.

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 secondary winding is then wound of insulated copper magnet wire over the insulated core with the turns equally spaced around the core periphery. When taps are pulled, they are wound in a manner that assures a fully distributed winding between any connections. The coil is then fully encapsulated in an ANSI 70 (sky grey) resin system that has been developed and tested for outdoor use. The potting compound is U.V. stabilized, is flexible to allow for expansions caused by temperature variations from -50°C to +65°C, has good chemical resistance, high dielectric strength, rugged physical properties to endure mechanical shock, and overall excellent weather resistance.

Connections:

The primary polarity H1/P1 is identified on its surface by an embossed white dot. The secondary terminals are ¼-20 silicone bronze studs provided with hex nuts and cupped washers. Terminal identification is permanently embossed 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 is identified by a white 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 adequate passing of wires from adjacent phases.