Watlow® has expanded the EZ-ZONE® ST integrated controller family to include phase angle power switching and increased load current. The EZ-ZONE ST now features single phase solid state relay output up from 40 to 75 amperes and phase angle power switching with soft-start to prevent high in-rush currents, load failure or blown fuses.Watlow’s EZ-ZONE ST with new phase angle control and higher current capacity is perfect for the production of PV cells where size and temperature uniformity are required to reliably produce a cell with high conversion yields. Radiant quartz (tungsten) lamps are commonly used in the manufacturing of PV cells to deliver a variety of specific thermal profiles rapidly. To overcome inherent limitations (low resistance / high in-rush currents), these heating lamps require phase angle power to function properly. These lamps are also usually ganged into small banks for improved temperature uniformity. For these banks, the requirement is temperature control, power switching, current monitoring, over-temperature protection and field communications yet remain small and compact. The EZ-ZONE ST meets all of these requirements.This expanded offering improves thermal uniformity, temperature repeatability and provides the functionality of multiple components and footprints collapsed into one. The newer size takes up less overall surface area inside the panel than an equivalent solution assembled from discrete devices. The design of the EZ-ZONE ST provides a complete thermal system kit to reduce project and engineering design time and is already tested and validated for the specified ampacity. The EZ-ZONE ST comes complete with a free internal communications bus (standard bus) which provides a single entry point for configuration and monitoring or location to access multiple controllers on the bus. For those applications requiring a display or remote user interface (RUI), the EZ-ZONE ST has the option of adding a 1/16 DIN RUI as a stand-along device or combining the RUI with gateway functionality. The gateway will access higher level field buses (PROFIBUS, Ethernet/IP™, DeviceNet™ or Modbus®) by converting standard bus to the field protocol once instead of outfitting each controller with an independent protocol card, and all at a much lower cost point.
