Programmable Ramp Soak PID Temperature Controllers
PRC-6000
PRC-489
PRC-300
PRC-309
PRC-312
Product Specification :
Model wise descriptions :
| Model | Description |
| PRC-967 | Ramp/Soak Programmable PID Temperature Controller (Bigger display) – Single profile of 16 steps |
| PRC-489 | Single input, Single profile of 16 steps Ramp / Soak Programmable PID/On-Off Temperature Controller. |
| PRC-300 | Ramp / Soak Programmable PID Temperature Controller – Single profile of 16 steps. |
| PRC-309 | S Ramp/Soak Programmable PID Temperature Controller – 1 to 10 profiles – each of 16 steps. |
| PRC-312 | Programmable PID temperature controller with 10 profiles each of 16 ramp/soak steps. |
Description :
Libratherm offers Microprocessor based multiple Ramp / Soak programmable PID temperature controller Models PRC-300, PRC-309, PRC-309-2 and PRC-310, which are designed to improve reliability, accuracy and control for all processing applications. It features Ramp and Soak functions (the capability to control the temperature and its rate of change over a predetermined time span). One to ten different patterns each of total sixteen (ramp/soak) steps can be programmed into the memory with the user-friendly membrane keyboard. Separate displays are provided to monitor simultaneously the Process temperature, Set temperature and the Program number. It can also be used as single set point control when the profile control is not desired. Inputs can be Thermocouple, IR Thermocouple, RTD Temperature Sensors, Voltage, Current Signals and etc.
It offers both switching outputs in the form of SSR or relay to drive external load contactor and continuous control outputs in the form of (4-20)mA or (0-5)volt etc., 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 load. Additional 2 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. To monitor the on temperature profile of the heating system, serial communication port on either RS232 or RS 485 interface can also be optionally provided, the same can be connected to the computer. Libratherm provides the window based software to view the on line behavior of the heating system in both graphical and tabular format.
Features :
• Accepts standard type of thermocouple or RTD(Pt-100)/2 or 3-wire input.
• Control output of Relay or TRAIC or DC pulse or (4-20)mA or (0-5)Volt or any other.
• Servo start from the process temperature.
• User programmable 10 different ramp/soak patterns
• Retention of program in case of power failure.
• Automatic program resumption.
• Facility of delayed start of heating cycle.
• Facility to use as PID and / or ON / OFF controller.
• Hardware security lock for unauthorized tampering of the set values.
Application :
• Heat Treatment
• Investment casting furnace of Jewellery
• Environmental Chambers
• Furnace / oven control
• Food processing
• Constant temperature bath etc.
Technical specifications :
| Design | Microprocessor based with 12 bit ADC and 8 bit DAC |
| Input | Thermocouple type J, K, R, S, B, C, D or RTD(Pt-100)/2 or 3-wire, (any one to be specified). |
| Two fixed inputs | Any two fixed inputs of same or two different types – back panel switch selectable. (facility available in PRC-309-2) |
| Range | Subject to the full range of the specified input. |
| Resolution | 0.1 / 1oC Subject to the specified input and range. |
| Indicating Accuracy |
Better than ± 0.1% of the range ( by software linearization of curves) |
| Display (PRC-300) | 4 digit 0.5” for process value. 4 digit 0.3” for set value and other parameters. |
| Display (PRC-309) | 4 digit 0.5” for process value. 4 digit 0.3” for set value and other parameters. 2 digit 0.3” for Program number and other codes. |
| Display (PRC-310) | 3 digit 0.5” for Process value, 3 digit 0.5” for set value (Max. display temperature = 999 oC) 2 digit 0.5” for current Program number, 2 digit 0.5” for step number 3 digit 0.5” for safety temperature and 3 digit 0.5” for remaining time of the current step. |
| Tuning | Auto / Manual tuning of PID values. |
| Control Algorithm | PID mode for heating control - (reverse action) On/Off mode with programmable hysteresis. Reverse action – as the temperature increases the control output decreases (OUT1) |
| PID values | Proportional Band (P)= 0.0 to 100.0% of Span, Integral value (I)= 0.00 to 5.00 resets/minute, Derivative value (D) = 0.00 to 5.00 minutes Cycle Time (CYC)= 2 to 100 seconds, On/Off Hysterisis (HYSt)= 0 to 50 oC, |
| Soft Start (rt) and Power Limit (PL) |
Built in power on soft start (rt) for analog output = 1 to 99 seconds. Power Limit to restrict the analog control output = 1 to 100 %. |
| Control Outputs | 1) DC pulses to drive external SSR, 2) (4-20)mA, RL max = 300 Ohms. or 3) (0-5)VDC, RL min = 10K ohms. |
| Ramp/Soak Steps | 1 to 16 Steps. (no restrictions in programming – a ramp can be followed by a ramp and a soak can be followed by a soak). |
| Set Temperature | Programmable for each steps in the full range of the specified input |
| Time per Step in PRC-300,310 |
1 to 540 mins. (9 Hr. per step). Two or more steps can be combined for longer time duration. |
| Time per Step in PRC-309 | 1 to 540 mins. (9 Hrs. per step) Or 1 minute to 100 hours (Two or more steps can be combined for longer time duration). |
| Program Hold Facility | Manual Hold or Auto Hold (Hold back feature for guaranteed Ramp/Soak facility) |
| Memory Backup | Retention of PID and set values in the non-volatile memory in the event of power failure. |
| Alarm Outputs | High or Low or End of Profile Alarm Relays (OUT2 and OUT3) (contacts rated for 5A @ 230VAC). |
| Serial Communication (Optional Feature) |
Optically isolated 2 wire RS485 on Modbus ASCII protocol. (in Slave mode). |
| Supply | 90 to 240 VAC ± 10% ( approx. 5VA), 50/60Hz. |
| Sizes | 96 x 96 x 160 mm , (PRC-300 and PRC-309) 192 x 96 x 160 mm (PRC-310) |
| Panel cut out | 92 x 92 mm and 186 x 92 mm +/- 0.5 mm |
| Enclosure | Metal Powder coated with ABS bazzel and polycarbonate front. |
