J-KEM Scientific 250 User Manual

Summary of 250

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    Temperature control for research and industry model 250 temperature controller user manual.

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    2.

  • Page 3: Warranty

    Warranty j-kem scientific, inc. Warrants this unit to be free of defects in materials and workmanship and to give satisfactory service for a period of 12 months from date of purchase. If the unit should malfunction, it must be returned to the factory for evaluation. If the unit is found to be defect...

  • Page 4: Index

    Index section page 1. Quick operating instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 kem-net data logging and control software . . . . . . . . . 5 2. Adjusting the controller for stable control with various heaters. . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.1 ...

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    Section 1: quick operating instructions the three steps below are the basics of using your temperature controller. The user’s manual is a reference that explains the controller more fully as well as some of its more sophisticated features. It’s recommended that new users unfamiliar with process cont...

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    Kem-net data logging and control software at the beginning of 2008, j-kem implemented a redesign of it’s research grade temperature and vacuum controllers. The redesign involved both the hardware running your controller and software for remote control and data logging. Hardware – the controller may ...

  • Page 7: Section 2:

    Section 2: adjusting the controller for stable control with various heaters 2.1 what is tuning. The controller's most powerful feature is its ability to regulate virtually any heater with stable temperature control. For stable control the controller requires two things; (1) the controller must be se...

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    It’s important to understand that this controller isn’t a simple on/off type controller (i.E. On when below the set point, off when above [though it can be made to work this way, see section 3.11]). Rather it’s a predictive controller. Based on the shape (slope) of the heating curve, the controller ...

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    Os1 us os2 t1 t2 t3 t4 quarter cycle times temp new tuning values loaded into memory time start at set point 75% of set point during t1 - 4 the controller measures heating delays and rates of heating and cooling heat to set point after entering new parameters the autotune sequence. During autotune t...

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    Autotune errors. The autotune routine can fail for several reasons. If it fails, the controller displays the error message “tune” “fail”. To remove this message turn the controller off for 10 seconds. Try the procedure titled “autotuning the controller for very fine control” above. If autotune fails...

  • Page 11: Section 3:

    Section 3: operations guide 3.1 front panel description. 1 2 3 4 5 6 7 8 9 10 11 - serial communications (on back) figure 1 1. Temperature display. Shows temperature of the process as the default display. Shows set point temperature (i.E. Desired temperature) when ‘*’ button is pressed. 2. Control k...

  • Page 12: Examples Of Program Ramps

    3.2 heater restrictions. The heating outlets (10) deliver 15 amps of current at 120 vac into resistive loads (heating mantles, hot plates, ovens, etc.). Use only resistive loads that are safely operated at 120 vac and require less than 15 amps or damage to the controller and a safety hazard may resu...

  • Page 13: Sprn

    Sprn setpoint ramp run. Allowable values: on, off, hold this parameter turns the ramp-to-setpoint feature on or off. During an active run, if this parameter is set to ‘hold’, the setpoint ramp stops and holds at its’ current value. This continues until the parameter is set to on or off. When set to ...

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    3.4 cooling outlet. The cooling outlet is set to be on when the process temperature is above the main set point (sp1) and off when below the main set point. If a normally closed solenoid valve controlling coolant flow were plugged into this outlet it would be open when the temperature was ‘too high’...

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    Example power setting explanation 80 ml toluene 100 ml flask 100 ml heating mantle sp = 80 o c 50 - 500 ml (25% power) organic solvents heated to 50 - 110 ≈ o c are set to the volume range on the front panel. When choosing between 2 power settings (i.E. 80 ml also falls within both the 10 - 100 ml r...

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    3.7 affect of power setting on heating profile. The following graphs show the effect of selected power levels on heating performance in a variety of situations. Each example contains 1 optimal and 1 or 2 less optimal settings demonstrating use of the power reduction circuit. 0 10 20 30 40 50 60 70 2...

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    0 10 20 30 40 50 60 70 20 45 70 95 120 145 170 temp c o time (min) conditions: 300 ml collidine 500 ml flask 500 ml heating mantle set point = 45 c power = 50 - 500 ml (25% power) o set point = 100 c power = 300 ml - 2 l (50% power) o set point = 155 c power = > 2 l (100% power) o graph 3 another fa...

  • Page 18: Procedure 1

    3.9 resetting the controller for use with heating mantles. If you want to use your controller with heating mantles after it’s been tuned for a different style heater, rather than autotuning the controller with the heating mantle, j-kem recommends that the controller be manually tuned by following th...

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    3.11 changing between pid and on/off operating modes. The controller can heat in either of 2 operating modes, pid (proportional, integral, derivative) or on/off mode. The difference between them is the way they supply power to the heater. In on/off mode (the simplest heating mode), the controller is...

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    3.13 troubleshooting. Problem cause corrective action large over shoot of the set point (> 3o) during initial warm-up or unstable temperature control. Output power level is set too high. Set the output power level to a lower setting (see section 3.6). Controller is not tuned for process being heated...

  • Page 21: Section 4:

    Section 4: application notes supplemental application notes on the following topics are available by contacting j-kem. Application note subject an1 how to heat oil baths with your controller. (included in appendix) an2 changing the controller’s thermocouple type. An3 changing the heating outlet into...

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    Would continue to rise – even though all power had been disconnected – until the range coil cooled down. This problem of overshooting the set point during initial warm-up is the major difficulty with process controllers. Overshooting the set point is minimized in two ways by your j-kem controller – ...

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    After the controller is reprogrammed, place a fine gage wire thermocouple ( 1/3 the size of kite string; available from j-kem) in the bottom third of ≈ the heating mantle and fit the flask snugly on top so that the thermocouple is in intimate contact with the heating mantle. Set the power reduction ...

  • Page 24: Appendix

    Appendix i. Using the controller with an oil bath application note #1 using your 200-series controller with an oil bath is usually not recommended. J-kem manufactures a 400-series controller designed for use with oil bath and is recommended for this application. The 200-series controller can be used...

  • Page 25: II.

    Ii. Safety considerations and accurate temperature control for safety critical and non-typical organic reactions (especially polymeric reactions) or for use with heaters other than heating mantles the user must either 1) monitor the reaction closely to verify the tuning parameters are appropriate fo...

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    Iii. Resetting the controller to original factory settings j-kem manufactures the most technically advanced temperature controller available and should give you consistently flawless control. If you have difficulty with your controller, a good place to start to correct the problem is by loading the ...