Geometrically designed to reduce excessive voltage gradients at connecting points and other areas needing shielding or balancing of electrostatic fields. Also an increase withstand voltage by improved grading and minimize corona. Many diameters are to IEC publication 52 standard metric sizes.

Many of Ross Engineering's line of toroids, spheres, and corona nuts have been designed to meet metric dimensions. The Ross toroids are made of aluminum while most spheres are made of either hollow aluminum or solid non-melting carbon with other materials optional. A satin finish is standard with a high polish finish available. Aluminum toroids and spheres are used to minimize corona and for adjusting voltage gradients on long stacks of high voltage components.  Spheres are also used for spark gaps and corona eliminating terminations. Carbon spheres are desirable where high current arcing is involved since they do not melt or develop pits or projections but tend to remain a smooth surface. Also, with the presence of slight amounts of Carbon 14, they have a tendency to have more consistent spark-over levels,

Ross Toroids come in two separable halves as standard. A one piece toroid is formed by heliarcing two halves together. Toroids, or hemisphere-toroid configurations, can be used in place ofspheres where height is limited. Available toroid diameters range from 1.9 cm to 132 cm (0.75 in to 52 in).  Mounting holes are optional and other sizes can be provided.

Ross Spheres are available in solid or hollow aluminum, solid carbon, or other materials upon request. Most sizes recommended by the International Electro Technical Commission (IEC) are standard. The aluminum spheres are usually used for limited current spark gaps or for terminations. Diameters of the standard spheres range from 0.5 cm to 56 cm (0.2 in to 22 in). The non-melting carbon spheres are used for calibrated spark gaps, lightning arresters on antennas, power supply overvoltage, and other transient suppression and high current spark discharge in pulse forming networks. The solid sphere diameters vary from 1 cm to 30.48 cm (.396 in to 12 in).

Ross Corona Nuts are a modification of a sphere or toroid shape and are widely used in moderate high voltage applications. Their recommended operating voltages are up to 300kV. Diameters of the corona nuts range from .64 cmto 3.8 cm (.25 in to 1.5 in).

Specifications and Dimensions are for reference only and are subject to change.
Contact Ross Engineering Corp. for current information.