Power Resistor Range And Specifications

There are many applications for a power resistor where a very substantial power rating is required that exceeds the wattage available from our range of power resistors. The current range of power resistors covers a range from power ratings from 5 watts to 1000 watts.

The corresponding ceramic former lengths range from, for example, 51mm for the DG series resistor rated at 20 watts, to 165mm for the HA series 100 watt resistor up to the YM type power resistor that has a 1Kwatt rating and has a ceramic length of 475mm.

There are numerous applications where a higher power rating is required. One such example was found in an air conditioning resistor bank installed in an Australian light rail transportation system. The system called for a 10,000 watt resistor bank that needed to exhibit high reliability and longevity and be easily mounted in a limited space.

YA Series Power Resistor Solution

After looking at the requirements for installing the 10Kwatt resistor bank into the light rail unit, it became obvious the best solution would be to employ 10 YM series power resistors engineered into a removable resistor bank assembly.

Short Time Overload Rating

1000 watt power resistor

YM series 1000 watt power resistor

The Y series power resistors have a short time overload rating of 5 times the rated load, ensuring a suitable tolerance should an overload condition apply to the resistor bank. Given the range of environmental conditions the resistors were likely to encounter in a light rail application it is important that the construction and coating of the resistors gives them excellent humidity and moisture resistant capability.

Resistor Specification

The final specification for the resistors was determined by the electrical parameters of the air conditioning unit along with the supply voltage. The final resistance of the individual resistors within the bank were calculated to be 27 ohms with a 5 percent tolerance. The resistor banks were assembled and installed into the rail carriages and have operated seamlessly now for several years. Correct resistor specification and selection is critical for reliable operation within most applications and considering temperature, environmental and housing of the resistors are factors that need to be taken into account also.