Libratherm offers Microcontroller-based Ramp/Soak Programmable PID Temperature Controller Model PRC-489 which is designed to improve reliability, accuracy, and control for all temperature control applications. It features Ramp and Soak functions (the capability to control the temperature and its rate of change over a predetermined time span). The single pattern of a total of 16 (ramp/soak) steps can be programmed and stored in the memory. It can also be used as single set point control when the ramp/soak profile control is not desired. The controllers are calibrated for K type thermocouple.

Control Outputs: This PID Pressure Controller PRC-489 offers both switching outputs in the form of SSR driver/Triac (AC SSR) for external SSR or external load contactor and analog output in the form of (4-20) mA or (0-5) volt control signal, which can be used to control heater power through external Thyristor Power Regulator. The analog outputs can be directly connected to Libratherm make single-phase/three-phase SCR based phase angle or zero cross over fired power regulators. Additional one/two relays are also provided for time or temperature-dependent event outputs as per the system requirement. The programmed profile and other parameters are retained in the nonvolatile memory in the event of power failure.

Thermocouple Break Protection: In the case of a thermocouple break, the control can be transferred to manual mode to continue the heating cycle and the user can alter the % of control output. The deviation hold feature assures guaranteed ramp. For quick heating from the ambient temperature, the hold feature is disabled in the very 1st ramp. Front Panel LED indicates the start and end of the cycle, the status of heater output, the status of the heating ramp, soaking, or cooling ramp. The unit of temperature measurement can also be selected as °C or °F as desired.

Auto Tracking Feature: In case of power failure during the normal heating cycle, the temperature is likely to drop. This PID Profile Controller has a special feature to auto-track the heating rate on the resumption of power supply. This is the unique feature of the controller and normally not available in other ordinary controllers.

Master-Slave Control Feature: For larger heating systems requiring more than one controller, the master/slave feature facilitates the user to program one controller as a master and others as a slave. The slave controller will follow the program fed in the master controller. This facility allows uniform heating of the bigger jobs. The master-slave configuration is achieved using the RS485 interface. Out of many controllers, anyone controller can be configured as a master controller and others as slaves. Single Master can control a maximum of 30 slave controllers.