Emerson 54e pH/ORP instruction manual Normal Mode, Analog Outputs

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MODEL 54e pH/ORP

SECTION 6.0

 

THEORY OF OPERATION

TPC offers precise control by forcing the pump to feed chemical for shorter periods of time as you approach the desired setpoint. If the process faces a large upset, TPC mode forces the pump to feed chemical for longer periods of time as the process deviates further from the setpoint. This action continues until the pump is feed- ing all the time, providing a speedy recovery from large up-sets.

The controller can be programmed to be direct or re- verse acting, depending on the pH (or temperature) value selected for URV. For example, if the controller is direct acting based on pH, such as in caustic chemical addition control, the pH will rise as chemical is added, so the URV value will be below the LRV (i.e. below zero). As the pH rises toward the control point value, the pump will be on for gradually less time. Conversely, if the controller is reverse-acting based on pH, such as in acid addition for control, the pH will drop as acid is added, and the URV value will be positive. The pH will fall toward the control point value, and the pump will be on for gradually less time.

Complete TPC configuration is explained and typical settings for these parameters are listed in Section 5.0. After startup, the operator needs to adjust only the 0% On to maintain the desired chemical concentration.

6.6 NORMAL MODE

Normal mode is on-and-off control based on an alarm setpoint. To prevent nuisance alarms, a hysteresis (deadband) setting, and/or a time delay can be pro- grammed during configuration. You can configure each alarm to trigger above the setpoint as a high alarm or below the setpoint as a low alarm. The operator need only raise or lower the alarm setpoint as necessary.

6.7 ANALOG OUTPUTS

The Model 54e pH/ORP controller includes a second analog output. An analog output produces an electri- cal current signal which varies in linear proportion to a value measured by the controller. You can configure the controller to produce a 4-20 mA or 0-20 mA cur-rent output proportional to pH or temperature. See Section 5.6 for programming details.

The analog output must be "scaled" so that 4 (or 0) mA corresponds to the low end of the scale and 20 mA cor- responds to the high end. The operator can scale the output as in the following example:

The Model 54e pH/ORP is connected to a strip chart recorder with a 0 to 100% scale. The average value of the bath is 10.0 pH, plus or minus 0.5 pH. The opera- tor wants to match this value with the 50% mark on the recorder. To do so, the operator selects 9.5 pH as the 4 mA value and 10.5 pH as the 20 mA value by enter- ing them as in Section 5.3. The chart on the recorder will display 0% when the pH is 9.5 or below and 100% when the pH equals 10.5 or greater. (this is for a 4-20 mA recorder).

The Model 54e pH/ORP is also capable of PID control where the analog output will be proportional to the dif- ference between the setpoint and the measured vari- able, either pH or temperature. This control mode is used to modulate a pump or valve, rather than to turn a device off and on.

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Contents PH/ORP Hart Analyzer/Controller Model 54e pH/ORPEssential Instructions Electrical Shock HazardPage Description and Specifications Model 54E PH/ORP Microprocessor AnalyzerSection Title Appendix Title List of TablesTable No Title Table of Contents List of Figures About This DocumentSection Description and Specifications General DescriptionDescription of Controls Relative Humidity 95%, non condensing Alarms Specifications Physical Specifications GeneralPower Current OutputsAnalyzer Specifications @ 25C Recommended SensorsOrdering Information Code OptionsPart NO. Description Locating the Controller Section InstallationMechanical Installation Unpacking and InspectionPanel Mounting Analog Output Wiring Section WiringPower Input Wiring Alarm Relay Output Wiring454EPH02 PH Sensor Wiring PH Sensor CompatibilityTions will Result in Controller MALFUNC- Tion 454EPH01 Cable Dressing Final Electrical Check Wiring to Model Section Calibration IntroductionHold Mode Off Adjust temp 25.1 CTemperature Calibration Autocal buffer Buffer 1 -- WaitAutomatic TWO-POINT Calibration Auto buffer cal done Use the arrow keys to select the correct bufferCalibration Notes Pt calibration done Calibrate pointPt 04.00pH 25C Manual TWO-POINT CalibrationStandardize 7.01 pH SINGLE-POINT pH CalibrationOutput trim Temperature Compensation OptionsTemp comp Auto 59.16 mV/pHHold Mode Output trimTrim Outputs Section Software Configuration PH Settings ListRanges Factory Settings User Settings Diagnostics Section Outline of Menu Levels Simulate tests Alarm High 14.00pHChanging Alarm Setpoints Setpoint 07.00 pHSetpoint + 06.90 pH Setpoint 7.00 pH4mA 0.00 pH 20mA 2.00 pH Changing Output Setpoints PID onlyMA 0.00 pH 20 mA 14.00 pH Output 1 12.00 mA OutputOutput MA +00.00 pHTesting Outputs and Alarms Alarm setpoints Output setpointsTest output Test alarm Simulated testsTest alarm 1 Open Test alarm 1 OpenDisplay right AL2 Measure pHDisplay contrast Timeout On Security CautionChanging Output Parameters Control ModeDisplay Output Control ParametersFault 22.00 mA Range 4-20 mAlRange 4-20 mA Hold feature setup Fault 22.00mAOutput 2 control Output 2 setup Hold Disable featureAlarms Alarm 3 controlInterval timer Hysteresis 0.01 pH Delay 0 sec Alarm LowSetpoint 0.01 pH Delay 0 sec Relay Default NoneTime period 30 sec Relay default NoneSetpoint +07.00 pH URV 2.00 pHTimeout 3600 sec Alarm FaultFeed limit Disable Alarm 4 SetupTimer Disable Recovery 600 secOn time 120 sec Interval Timer Examples Diagnostics Diagnostics OffZero offset 60 mV Autocal Standard DiagnosticsAuto Calibration Setup Stabilize pH 0.01 pH Stabilize time 10 secAuto Calibration Setup Standard BuffersContinuous Sensor Diagnostics Section Theory of OperationInterval Timer Typical set pointsSee .8 for instructions on chang- ing these setpoints Alarm Relays Time Proportional Control TPC Mode CodeNormal Mode Analog OutputsCondition Definitions Controller Mode PriorityController Mode Priority Chart Action DefinitionsPID Control PID Control Mode CombinationsPID Control Code Measurement and Set Point Feedback ControlProportional Mode Gain Proportional Gain Plus Integral ResetControl Loop Adjustment and Tuning Process Reaction Curve Method Process Reaction CurvePID Control Section Special Procedures and Features Password ProtectionLevel 1 3 Password Privileges Custom Curve Configuring SecuritySecurity Lock allSolution Temperature Compensation Temp coeff +.000Sensor iso 07.00 pH Operate iso +07.00 pH Section Troubleshooting Troubleshooting is easy as 1, 2, 3…Diagnostic Messages Diagnostic Messages Description of problemQuick Troubleshooting Guide Symptom ActionDiagnostic Variables Theoretical pH vs. Millivolt Values at 25C 77F Troubleshooting Procedure Troubleshooting GuidelinesTemperature Compensation Circuit Ohms Ambient TemperaturePreamplifier Troubleshooting Procedure Preamp in a junction box FigureController preamp check Figure Junction Box Preamplifier Check Troubleshooting Guide No PowerCoated glass electrode Clean with soft cloth and clean water Password protected Replacement Parts Part Number DescriptionSection Return of Material Warranty RepairNON-WARRANTY Repair GeneralAppendix a ORP Configuration Quick Startup ORPTable A-1. ORP Settings List Item Choices ORP Settings User SettingsChoices ORP Settings User Settings Diagnostics SectionOutput setpoints Simulated testsStandardize 400 mV ORP CalibrationReturn of Materials Request Sensor or Circuit Board onlyWarranty Return of MaterialSpecifications subject to change without notice
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