Ley de Ohm y Productos

QUÉ ES LA RESISTENCIA ELÉCTRICA Resistencia eléctrica es toda oposición que encuentra la corriente a su paso por un circuito eléctrico cerrado, atenuando o frenando el libre flujo de circulación de las cargas eléctricas o electrones. Cualquier dispositivo o consumidor conectado a un circuito eléctrico representa en sí una carga, resistencia u obstáculo para la circulación de la corriente eléctrica. QUÉ ES EL OHM

Un Ohm es la resistencia eléctrica que existe entre dos puntos de un conductor, cuando una diferencia de potencial constante de 1 volt aplicada entre estos dos puntos, produce, en dicho conductor, una corriente de intensidad de 1 amper (cuando no haya fuerza electromotriz en el conductor). Se representa por la letra griega mayúscula omega (Ω). También se define como la resistencia eléctrica que presenta una columna de mercurio de 106,3 cm de altura y 1 mm² de sección transversal a una temperatura de 0 °C

Según la Ley de Ohm, un dispositivo tiene una resistencia de un ohmio si una tensión de un voltio produce una corriente de un amperio. Lo que matemáticamente se expresa así:         

 Tipos de Resistencias que Fabricamos :



-Resistencias tubulares de Cerámica 

-Resistencias Tab Weld

-Resistencias Neutro a Tierra

-Resistencias EdgeWound

-Resistencias tipo WireWound

-Resistencias Frenado Dinámico para Locomotoras, Camiones Mineros  Variadores de Frecuencia y otras aplicaciones.

Corrugated Tape Wound Power Resistors

Dynamic Braking Grid Resistor

Dynamic Braking Grid Resistor

Dynamic Braking Grid Resistors  are suitable for haul Trucks and Locomotives  that are under sustain severe operating conditions. Resistors Grids are designed to withstand considerable mechanical shock and vibration, but include design features that limit excessive weight and space. 

Typical environments include exposure to rain, snow and ice with road conditions that create persistent dirt . Units are designed to endure the above standards and also meet the electrical and thermal  parameters of our customer’s specification.

Our standard design focuses on the importance of the resistor element and its reliability. The grid resistor design is critical, and we consider our element superior to any other product available on the market.

We supply Braking Resistor Grids for all models  (GE and EMD type locomotives) and Haul Trucks, whether they are 40 years or 4 months old.

GE Type Braking Resistor Grid

EMD Type Braking Resistor Grid

Resistor @Work

Motor Control Resistors

Motor Control Resistors

Motor control is one of the most common applications of power resistors. Resistors are used to control the torque and speed characteristics of AC and DC motors, and to limit currents. 

Our engineers will design a package that best suits your needs.

NEMA Standards for Motor Control Resistors are applicable in our products.

NEMA Classification Chart of Resistors

(NGR) Neutral Grounding Resistors

Neutral Grounding Resistors

Neutral Grounding Resistors are used in industrial power systems for resistance grounding of wyeconnected generators and transformers. A neutral grounding resistor limits the fault current to a value which is sufficient enough to operate protective relays, yet prevent unwanted fault damage.

Neutral grounding resistors are rated in line-to-neutral voltage (system voltage divided by 1.732), initial fault current and maximum time 

Neutral grounding resistors are designed to dissipate the required amount of energy and not exceed the temperature limitations of IEEE Standard 32-1972. As defined in this publication, the time and temperature ratings for neutral grounding resistors are as follows: 

Short time: 

Short time ratings are 10 and 60 seconds. Since short time rated resistors can only withstand rated current for short periods of time, they are usually used with fault clearing relays. The short time temperature rise for the resistive element is 760°C. 

Extended time: 

A time on rating greater than ten minutes which permits temperature rise of resistive elements to become constant, but limited to an average not more than 90 days per year. The extended temperature rise for the resistive element is 610°C. 

Continuous: 

Capable of withstanding rated current for an indefinite period of time. The continuous temperature rise for the resistive element is 385°C.

Resistor Assembly: 

The resistor coils consist of a stainless steel edgewound element wound around a ceramic core supported on a through-rod. Glazed insulators are attached to each end of the coils and fastened to a heavy gage, corrosion resistant frame. The unit is designed to permit the expansion of supporting rods when submitted to high operating temperatures. Resistor elements are joined by stainless steel connectors, which are welded in place, to form a positive electrical path.

Enclosure: 

Our resistor assemblies are available with grounded safety enclosures to protect personnel and wildlife from harm. Screened and louvered enclosures are available in a variety of finishes including painted, powder coated, galvanized, hot-dipped galvanized, aluminum and stainless steel. Options: A number of additional options are available including entrance bushings, current transformers and elevating stands.

Follw us in Twitter: @ResisElectrom

Need help? , e-mail us: ventas@resistenciaselectrohm.com

www.resistenciaselectrohm.com

Dynamic Braking Resistors

 Dynamic Braking Resistors

The drive manufacturer normally determines the power rating (watts) needed to prevent overheating during braking duty. 

The peak braking current is determined by the specified resistance value. 

Each drive manufacturer specifies a resistance range with a minimum to prevent overcurrent and damage to the drive and a maximum value to give adequate lower dissipation capability.

Dynamic Braking Resistors that can be delivered quickly, completely assembled, and ready for convenient installation. Dynamic Braking Resistors are used with AC VFD’s to produce a braking torque in the motor during overhauling conditions. The dynamic braking resistor is connected across the DC bus and will see voltages as high as 800 volts.

Follow us @ResisElectrohm

www.resistenciaselectrohm.com

Dynamic Braking Resistors made to last .