Heater bundles with local power switching

Abstract

A heater system (10) includes a heater bundle (12). The heater bundle (12) includes at least one heater assembly (18), where the heater assembly (18) includes a plurality of heater units (52), and more than one of the heater units (52) defines at least one independently controlled heating zone (62). The heater bundle (12) includes a plurality of power conductors (42) electrically connected to the independently controlled heating zone (62). The heater system (10) includes means for determining temperature and at least one power switch (120), the power switch (120) disposed proximate the heater bundle (12). The heater system (10) includes at least one controller (15) configured to modulate power to the independently controlled heating zones (62) through the power conductors (42) based on the determined temperature to provide a desired power output along a length of the heater assembly (18). The controller (15) is configured to provide power to the power switch (120). Figure 1