All You Need to Know About Wire Wound Resistors

A wire wound resistor is an electrical passive device part that limits the supply of current. The metallic wire which is winded around the core of non-conductive material helps in resisting high wire material. Wire wounded resistors are the oldest type of resistors that are still manufactured today. Wire wound resistors are mainly formed of glass, ceramic and plastic. As many basic designs are available that helps in manufacturing them they can be made with accuracy and are best for low resistance and high power ratings.

Wire wound resistors are of following types:

• Precision Wire Wound: These wire wound resistors are basically used in measuring bridges and calibration equipment. The stability of these resistors is very good. These resistors ensure that the required resistance range vary according to circuit conditions.


• Power Wire Wound: These kind of wire wound resistors range varies from 0.5 Watt to more than 100 Watts. These wire wounds are needed for very high power workings. These are quite strong resistors which can bear up to 300 degree Celsius. These power wire wound resistors are available with silicon and enamel coating. Majority of power wire wound resistors have ceramic core and ceramic coating to safeguard the wiring. Usually they are manufactured with leads that allow for vertical or horizontal mounting.


• Potentiometer Wire Wound: Potentiometers wire wound resistors are mainly used in circuit breakers and fuses. Because of their high power potentials, wire wounds are needed in common circuit breaker application. These are needed where there are chances of high fluctuation and are required to correct the fluctuation before tripping.

Specification

Resistance wire                 Nikrome or constandan or eureka
Standard Tolerance             5%
Dielectric Strength             1000 V RMS
Temperature Coefficient       20 PPM to 130 PPm per C
Power Derating                  250 C full Load
Stability                             Less than 3% after 84 days Load test
Core                                  High purity porclean / stealite
Tags                                  Mild steel / brass with tin plated
Standards                          Meets functional requirements of Mill-R 26/LCSO/ISI