16 February 2015. Continuing on with out wire wound resistor selection series, this week we take the example of a high power resistor – namely a 500 watt power resistor. In this example our application calls for a 500 watt rated resistor that has a 5 percent tolerance and 470 ohm adjustable resistance.
A 500 watt rated resistor, by its very power rating, calls for a rugged, highly reliable method of construction, with the ability to dissipate significant amounts of heat from the body of the resistor. From our wire wound resistor product selection guide, we can see that the Y Series power resistor meets the requirements for our resistor requirement: The Y series includes:
- 500 watt resistor rating in the YA model.
- An adjustable version is available for resistances ranging from 2 ohms to 110K ohms
- Easy mounting via a rod mount with standard M8 thread
- Excellent moisture resistance
- Good overload rating – in this instance the Y series has a short time overload rating of 5 times its rated load – in this instance equivalent to 2500 watts
Where high power ratings are required for resistors, engineers will generally look at the quality of construction of the resistor assembly. Because power resistors, by the very nature of their construction, need to dissipate a lot of heat, the reliability, long term of the resistor is very much tied into the materials used in the construction of the resistor and the manufacturing procedures and techniques used. The YA Series has an excellent reputation for long term reliability in a wide range of applications.
