Telema - Electric Power Resistors for Railway Systems

Telema Spa, a company belonging to the Telema Group, is one of the world's leading specialists in electric power resistors. Telema produces a range of power resistors designed specifically for railway equipment, including dynamic braking resistors, snubber resistors and crow bar resistors.

Telema's electric power resistors also include neutral earthing resistors, load resistors, harmonic filter resistors and starting / braking resistors.

POWER RESISTORS FOR RAILWAY APPLICATIONS

Telema manufactures and supplies power resistors that cover all the applications of resistors in railway systems. These products are:

• Dynamic braking resistors
• Snubber resistors
• Filter charging / discharging resistors
• Crow bar resistors
• di/dt resistors

With a full range of elementary components, a fully industrialized and very simple assembly and our property simulation and design software, Telema is able to achieve the best possible characteristics typically required by a traction resistor: minimum weight and bulk, high reliability, a low operating temperature, high vibration resistance and a long lifecycle.

NEUTRAL EARTHING AND GROUNDING RESISTORS

Ensuring the protection of transformers and generators against ground fault currents, neutral earthing and grounding resistors limit the fault current to a pre-fixed value so as not to damage the unit. Telema's neutral grounding resistors range from class 3.6kV to 72.5kV with current at several thousand amperes and chassis protection from IP 23 to IP 55. These resistors can incorporate load-less switches, load-break switches, vacuum contactors, CT, VT, etc.

LOAD RESISTORS

Telema's custom-designed load resistors are made of low temperature-coefficient resistance materials to exacting tolerances. They provide an accurate and stable load to minimize unwanted variables in your testing.

HARMONIC FILTER RESISTORS

Harmonic distortion, caused by the increasing use of solid-state devices in power systems and controls, can create complex waveforms which feed harmonics into power systems, causing problems with equipment connected elsewhere in the system, such as excessive noise, erratic functioning, overheating and outright failure. Filters, consisting of tuned RC circuits, are used to remove such harmonics. Since RC circuits can be difficult to tune, resistors are often used to increase bandwidth.

STARTING AND BRAKING RESISTORS

Telema also makes rugged, stainless steel resistors designed to provide trouble-free service. They are in service on cranes and heavy industrial drives all over the world.

ABOUT TELEMA

Telema's head offices and production unit, totalling 11.000m², are located in the town of Piacenza, whilst the company's commercial offices are situated in Milan.

Telema's activities have always focused foremost on the client's requirements. Telema's involvement as a technological partner to solve any problem related to power resistors has proved to be a winning philosophy, providing constant growth in turnover.