Glossary of Terms - S

S-Link - CPS's dual element constructed fuse link with very slow time-current characteristics.

Sealed Transformer - Completely sealed from outside atmosphere and usually contains an inert gas which is slightly pressurized.

Secondary Taps - Taps located in the secondary winding (refer to Taps).

Secondary Voltage Rating - Designates the load circuit voltage for which the secondary winding (winding on the output side) is designed.

Secondary Winding - The transformer winding connected to the load or output side.

Series Gap - Internal gap(s) between spaced electrodes in series with the valve elements across which all or part of the impressed arrester terminal voltage appears.

Series/Multiple - A winding of two similar coils that can be connected for series operation or multiple (parallel) operation.

Sine Wave - The waveform produced by rotating a loop of wire at uniform speed in a magnetic field and measuring the voltage that is induced, along with the angular displacement of the wire.

Slow speed Ratio - A speed ratio of melting characteristics from 10-13 (see Speed Ratio).

Sparkover - A disruptive discharge between electrodes of a gapped protective device.

Specialty Arrester - An arrester designed specifically for a particular application to meet the specified needs of that application. Riser pole and under-oil are specialty arrester.

Speed Ratio - A ratio given for the time current characteristics of fuse links; the ratio of the 0.1 second minimum melting current to the 300 or 600 second melting current (300 seconds for fuse links rated 100A and less, 600 seconds for 140 and 200 A ratings).

Station Class Arrester - A classification of 3-684 kV rated arresters which typically have had the greatest degree of protection (prior to VariGAP), the highest level of energy handling and durability and pressure relief capability up to 80 kA and above on some ratings.

Steady State - A condition in which circuit s values remain essentially constant, occurring after all initial transients or fluctuating conditions have settled down.

Storm Trapper - CPS's low voltage arrester with a 1500 A duty cycle rating and 10 kA high current short duration rating.

Storm Trapper H.E. - CPS's low voltage arrester with a 5000 A duty cycle rating and 40 kA high current short duration, hence H.E. (high energy).

Stress, Voltage - A transient current of voltage usually associated with lighting or switching.

System Capacity - Represents the ability of a system to meet its customer's needs, or the electrical demand of its customer. System capacity is provided by generators, transmission lines, distribution networks and load management.

System Voltage - The rms power frequency voltage from line-to-line as distinguished from the voltage from line-to-neutral.

Surge - Transient current or voltage associated with lightning or switching

Switchgear - A general term covering switching and interrupting devices and their combination with associated control, metering, protective and regulating devices; also assemblies of these devices with associated interconnections, accessories, enclosures and supporting structures, used primarily in connection with the generation, transmission, distribution and conversion of electric power.

Switchgear Assembly - An assembled piece of switchgear equipment (indoor or outdoor) including but not limited to one or more of the following: switching; interrupting; control; metering; protective and regulating devices, together with their supporting structures; enclosures; conductors; electric interconnections and accessories.

Switch, Limit - A switch that is operated by some part or motion of a power-driven machine or equipment to alter the electric circuit associated with the machine or equipment.

Symmetric - A term used to explain the normal, rhythmic ac flow of current (transient or dc component = ); the steady state component of any current or fault current calculation.

Systems Capacity - Represents the ability of a system to meet its customers' needs, or meet the electrical demand of its customers. System capacity is provided by generators, transmission lines, distribution networks and load management.

Glossary Index