The SCR control can deliver electrical power to heaters in several ways: phase angle fired, zero voltage switched and on/off control. These controls proportionally turn on a percentage of each power line half cycle. This gives smooth, infinitely variable application of power to the heaters. A side benefit is that the heaters ramp up and down regarding tube temperature, an SCR can extend heater life many times over other control methods. Since the SCR is solid state, it can cycle on and off over a million times. Potential to prevent immediate power spikes may save utility costs over a step or on/off control.

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