Disconnectors & Earthing Switches — High-Voltage Catalogue (Siemens Energy Brazil)

About Siemens Energy: experience and product strengths

Siemens Energy operates a business unit dedicated to manufacturing high-voltage disconnectors and earthing switches for open-air substations. Working from an extensive product portfolio and associated services, it develops solutions optimized both technically and economically for each customer, with quality assured under ISO 9001 and proven across varied installations in Brazil and worldwide. The company is the main manufacturer of disconnectors and high-voltage earthing switches in Brazil, drawing on more than 80 years of experience inherited from Siemens; its factories combine modern production technology with a skilled team, aligned with the group's global sustainability commitments.

The portfolio is designed for extreme environments: applications are available for seismic activity, ice loads up to 20 mm, and temperatures from -50 °C to 50 °C.

Key strengths across all families: subsets arrive pre-assembled and preset from the factory; the moving part of each main blade is individually tested; assembly and commissioning on site are intuitive and documented; contacts are silver-made for high conductivity and self-lubrication (less maintenance); technical assistance covers the entire disconnector service life; and products are recyclable at end of life.

Voltage and current range by family

A portfolio matrix maps each disconnector and earthing-switch family to its available voltage classes and maximum nominal current. The DAL family additionally lists a 1 s short-time withstand of 40000 A at 72.5-245 kV. TC and GTF earthing switches carry no nominal-current rating (not applicable). Empty cells mean the family is not offered at that voltage.

Maximum nominal current In (A) per family and voltage class, exactly as tabulated:

Contact system and arc restrictors

The common contact system is engineered so that contact force increases during a short-circuit and remains stable throughout the service life. The silver surface improves electrical conductivity and acts as a lubricant. Contacts are maintenance-free for 20 years under normal conditions of use, built from few pieces, and resistant to an ice layer of up to 20 mm.

Arc restrictors can be supplied for every disconnector type. They let the disconnector manoeuvre the induced currents that arise during busbar transference: switching from bus 1 to bus 2 creates a potential difference that draws an electrical arc between the contacts. Annex B of IEC 62271-102 describes these manoeuvre loads; Siemens Energy's bar-transfer arc restrictors are type-tested with more than 100 operational cycles of current establishment and interruption.

3DV8 command (operating mechanism)

The 3DV8 command cabinet drives the disconnectors. It provides generous space for cables and connections, protection against condensation, and can also be safely operated manually.

The mechanism is easy to assemble and maintain, requiring revision only after 1000 manoeuvres.

EVL — vertical opening disconnector

The EVL uses three insulating columns: two fixed (supporting the fixed contacts) and one rotative (turning the movable contacts). The vertical opening permits a small distance between phases, and a double-kinematics locking system keeps excellent contact even above 50 kA short-circuit. Designed lifetime exceeds 30 years.

Closing happens in two movements: the first approaches the contacts, then the contact force is generated by blade rotation around its own axis before the blade locks — a low-torque, smooth motion. Each pole mounts on a compact galvanized-steel base with maintenance- and lubrication-free bearings. Arrangements can be side by side or aligned, adaptable to higher nominal and short-circuit currents, with earthing-switch and bus-transfer attachments available.

DAL — double lateral opening disconnector

The DAL requires three insulating columns — two lateral fixed and one rotative at the centre. The central column supports the main blade; the lateral ones support the fixed contacts. It suits substations where the space between phases is limited, and its contact system uses few components, giving low electrical resistance during manoeuvres. Designed lifetime is over 30 years.

The main contact system uses a pair of contact fingers on each side of the main blade, and the bus transfer is fixed directly at the terminal. Earthing-switch and bus-transfer attachments are available, and the design adapts to higher nominal and short-circuit currents.

RDA — double lateral opening disconnector

The RDA also uses two lateral fixed columns and one central rotative column, and targets substations where vertical space between phases is limited. Its main blade is built with steel tubes for greater robustness of the live part, the contact system uses double kinematics, and it offers a high operating interval before decommissioning.

Opening and closing follow the double-kinematics sequence: the first movement approaches the contacts, the second locks them; only after locking is the torsion spring released, making the main blade rotate and strongly grip the contacts.

BC — central opening (centre-break) disconnector

The BC requires two rotative insulating columns that support the movable contacts, with closing realized at the centre of the opening. It is ideal where vertical space between phases is limited. The main blade is built of aluminium plate, and current is conducted through the joints by a bundle of tinned copper foils, giving a high operating interval before decommissioning.

The main contact system is of a "Reverse Loop" type: a set of contact fingers at one end of the active part and a vertical contact attachment at the other. Earthing-switch and bus-transfer attachments are available.

EVR — reverse vertical opening disconnector

The EVR is ideal for uneven busbars. It uses two insulating columns — one fixed and one rotative supporting the main blade — plus a further fixed insulating column that is inverted. It can be connected directly to the busbar, dismissing the inverted insulating column, and its locking system assures contact integrity.

The contact system consists of fingers locked by a double kinematic system: during closing the blade first approaches the fixed contact, then rotates; on reaching the fixed contact the blade locks and the rotation completes the adjustment, leaving the contacts firmly locked.

LAV — semi-pantograph opening disconnector

The LAV is an ideal disconnector for uneven busbars, using two insulating columns — one fixed and one rotating that supports the main blade — plus another fixed insulating column that is inverted or connected directly to the busbar. It has a lower space requirement in the horizontal direction, and its clamp locking system ensures excellent contact even during short-circuits up to 40 kA. The fixed contact can be mounted directly on the busbar.

The contact system is made of clamps that lock firmly at the end of the movement, spring-locked in a double kinematic system: the first movement brings the contacts together, and from a point close to the busbar the second movement closes the clamps, locking them firmly.

LAH — semi-pantographic opening disconnector

The LAH requires three insulating columns: two fixed (supporting the main blade) and one rotative (movable contact). Each pole is individually levelled, assuring stability and perfect levelling of the set; the design accounts for all shorting, operating and conductor efforts; and the main blade is perfectly balanced for a complete, smooth and stable manoeuvre.

Like the LAV, its contact system uses spring-locked clamps in a double kinematic arrangement — contacts are brought together first, then near the fixed contact the clamps close and lock firmly. An earthing-switch attachment is available.

GTF and TC earthing switches

Both earthing switches require a command and a grounding blade, which can come pre-assembled or be ordered later. They are modular components that fit every product in the range, include a mechanical interlock that prevents short-circuits, use factory-dimensioned counterweights, and are designed for a lifetime of over 30 years. The TC/GTF earthing switches adapt to any project's needs and can be acquired with the disconnector set or in a later purchase without affecting disconnector operation or the earthing blades.

The GTF contact system is supported by fingers that fit strongly together, locked by a double kinematics system: the first movement leads the fingers to the contact, and the second shifts the blade up, fixing it in its contact. GTF ratings: 145 kV (impulse 650 kV, 63 kA 1 s, 160 kA peak); 245 kV (950 - 1050 kV, 63 kA, 160 kA); 362 - 550 kV (1175 kV, 63 kA, 160 kA); 420 kV (1175 kV, 50 kA, 130 kA); 550 kV (1175 kV, 50 kA, 130 kA); 800 kV (2100 kV, 50 kA, 130 kA).

The TC contact system works through a simple locking mechanism: the main blade carries a silver contact bar that connects to a fixed contact containing pressure springs, strengthening the electrical connection and preventing the switch from opening. TC ratings are tabulated below.

Figures & drawings

Click any figure to enlarge.