Electric furnaces use large amounts of power and operate at high temperatures. The chamber within the furnace is split into multiple zones hence providing excellent temperature uniformity, each zone is independently controlled. The furnace heating elements are supplied with power via large industrial relays called contactors. Due to the very high currents being switched the contactors are subject to extreme wear resulting in frequent failure. The cost to replace the contactors is high, when down time is taken into account and repeated loss of production due to unscheduled outages. Heating elements are also prone to failure over time due to ageing, resulting in out of spec material and costly production delays. The contactors also contribute to the ageing effect of the heating elements. To extend the life of the contactors the output duty cycle within the temperature controllers is typically set.