Libratherm offers Microprocessor based Eight Zone RampSoak programmable PIDOn-off Temperature Controller (Model PRC-8000) where accurate temperature control of multiple zone rate of heating, cooling and soaking is required. PRC-8000 is as good as 8 individual rampsoak program controller in a single unit. Each zone can be independently programmed for 1 to 16 steps of RampSoak profile. Each loop parameters like PID, Hysteresis, Deviation hold and facility to skip unused channel etc. can be programmed from the user-friendly front panel membrane keyboard. The programmed profile and other parameters are retained in the non volatile memory in the event of power failure. PRC 8000 accepts 8 Thermocouples or RTD , Pt-100 3 wire inputs and can provide switching PID or ONOFF Control output in the form of DC Pulses or SSR or relay to drive external load contactor drivers for heating and cooling. It can simultaneously provide 8 analog PID control outputs in the form of (4-20mA) or (0-5) volt, which can be used to control heater power through Thyristor power pack (for electrical heating system) or to control the position of a modulating motor valve (for oil or gas fired heating systems). The analog outputs can be directly connected to Libratherm make single phase three phase SCR phase angle fired power controller which is ideally suitable for both resistive and inductive heating loads. Open or Faulty sensor indications for each zone is also displayed with the respective Zone No. It also provides common High and Low alarm relay outputs which can be used for external temperature dependent inter locking or audiovisual alarm.
The display scan rate is programmable from 1 to 99 seconds, whereas the internal control scanning is at the rate of 100mS.
Separate displays are provided to indicate simultaneously the Process temperature, Set temperature and the channel zone number. There is also a provision to view on demand the on line status of the running program viz., Percentage control output, remaining time of the current step, set point of current step, step no. in progress, etc.
PRC-8000 can also be used as single set point ON OFF controller when the profile control is not desired.
The deviation hold facility ensures uniform temperature of all 8 zones under control. Page 1 For graphical representation of the actual process in progress, duplex thermocouple can be used which can be connected to a chart recorder to track the behavior. PC based software for data logging to a PC is also available on request .

PRC-8000 is available in standard 12 DIN (192 x 96 x 200mm) size for 8 zones, 6 zones or 4 zones. It operates on 230 VAC with built in high and low supply voltage trip circuits. It is also protected against industrial RFIEMI Interference.

MODEL PRC 8001 Single Zone Control with 8 digital outputs is developed for sintering press to operate pressure valves at different temperatures.
Application

Mainly designed for pre and post welding stress relieving heat treatment cycles. Also suitable for multi-zone heating systems requiring rampsoak control.