Emerson manual Maximum Restarts, Rosemount 848L, Reference Manual

Page 83
Maximum Restarts

Reference Manual

00809-0100-4696, Rev AA September 2004

Rosemount 848L

Maximum Restarts

A large motor is too expensive to replace if it burns up because the operator wanted to give it another try, when in fact the pump was jammed. The life of the contactor is also shortened when it has to interrupt locked rotor current. In this case, it is normally possible for the motor to clear the jam on the second or third try. A counter limits the number of starts to 3, for example, within a preset time since the first attempt.

Notice that C1 in EQ1 and T2 in EQ2 are forward references that cannot have a bad status. A Bad status at channel 2 (the start button) will propagate to all of the equations and make the output Bad. A bad stop button or confirm contact will only make the output Bad. The I/O transducer block parameter OUT_1_CONFIG.FAIL_SAFE defaults to Fail False, which will stop the motor on any bad input status, or it may be set to Fail Last Good, which will not allow the stop button to turn it off. You probably don’t want to uses input devices with status for this application.

 

 

 

 

 

 

2

C1

 

 

 

T1

+

--------

/------------------------

 

 

( )--

+ EQ1

 

 

 

 

 

 

T1

 

 

+

-----+

C

+

----------------------

 

Count------

( )--

+ EQ2

T2

 

 

 

+

----------------------

 

Reset

 

 

 

 

+-----

+

 

 

 

 

 

 

 

C

 

 

 

 

T2

+

-----------------------------------

 

 

 

( )--

+ EQ3

 

 

 

 

 

 

1

T1

 

 

 

Out1

+

-- --+--

--

+----------------------

 

( )--

+ OUT1_EQ

 

 

 

 

3

 

 

 

+--

--

+

 

 

 

 

 

 

 

 

 

Rung T1 is equation 1. The pulse time must be set to the allowable on time for the locked rotor condition to prevent tripping the overloads, in this case 2.5 seconds.

The expression is TP(AND(IN(2),NOT(EQ(2))), 25);

Rung C is equation 2, which counts the attempts to start, and holds at the count until the 30 minute timer expires.

The expression is CTU(RISE(EQ(1)),EQ(5), 3);

Rung T2 is equation 3, the 30 minute timer:

The expression is TON(EQ(2),18000);

Rung Out1 is output equation 1:

The expression is AND(IN(1),OR(EQ(1),IN(3)));

E-7

Image 83
Contents 00809-0100-4696,Rev AA September Reference ManualFOUNDATION Fieldbus Rosemount 848L Discrete LogicTemperature Transmitter with Rosemount 848LRosemount 848L Table of ContentsSECTION 1 Introduction SECTION 2 Installation SECTION 3 ConfigurationRosemount 848L SECTION Operation and Maintenance APPENDIX AReference Data APPENDIX B Product Certifications APPENDIX C Function BlocksRosemount 848L APPENDIX D Logic Equation Syntax APPENDIX EMotor Control APPENDIX F Valve ControlTOC-4 Rosemount 848LReference Manual Rosemount 848L SAFETY MESSAGES WarningsSection IntroductionRosemount 848L OVERVIEWTransmitter Manual00809-0100-4696,Rev AA September Rosemount 848LReference Manual Reference Manual Rosemount 848LRosemount 848L InstallationSAFETY MESSAGES Warnings MOUNTING SectionReference Manual Mounting to a DIN Rail Without an EnclosureMounting to a Panel with a Junction Box Rosemount 848L00809-0100-4696,Rev AA September Mounting to a 2-InchPipe StandRosemount 848L Reference ManualReference Manual WIRINGPower Supply Connections Rosemount 848LRosemount 848L SWITCHESSurges/Transients GROUNDING00809-0100-4696,Rev AA September Rosemount 848LReference Manual Rosemount 848L I/O WIRINGDISCRETE INPUT WIRING CONFIGURATION DISCRETE OUTPUT WIRING CONFIGURATIONReference Manual TAGGINGRosemount 848L Reference Manual INSTALLATION Using Cable GlandsTRANSMITTER LABEL Rosemount 848LReference Manual Using Conduit EntriesRosemount 848L Rosemount 848L ConfigurationOVERVIEW SAFETY MESSAGES Warnings SectionReference Manual GENERAL BLOCK INFORMATION ModesRosemount 848L Reference Manual Link Active Scheduler Block InstantiationRosemount 848L Reference Manual RESOURCE BLOCK FEATURES and FEATURES SELCapabilities Rosemount 848LReference Manual MAX NOTIFYRosemount 848L Reference Manual PlantWeb AlarmsRosemount 848L 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual Reference Manual Alarms I/O TRANSDUCER BLOCKRosemount 848L Reference Manual LOGIC TRANSDUCER BLOCKRosemount 848L Figure 3-1.848L Logic Transmitter Data Flow Rosemount 848LReference Manual 00809-0100-4696,Rev AA September00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual Reference Manual DISCRETE INPUT BLOCKSRosemount 848L Rosemount 848L DISCRETE OUTPUT BLOCKSMULTIPLE DISCRETE INPUT BLOCK MULTIPLE DISCRETE OUTPUT BLOCKReference Manual Rosemount 848LRosemount 848L Section 4 Operation and MaintenanceFOUNDATION FIELDBUS INFORMATION SAFETY MESSAGES WarningsCommissioning MAINTENANCECommunication/Power Resetting the Configuration RESTARTNAMUR Sensors TROUBLESHOOTINGI/O Transducer and Logic Block Troubleshooting Resource BlockReference Manual Rosemount 848LRosemount 848L SPECIFICATIONS Functional SpecificationsAppendix A Reference Data00809-0100-4696,Rev AA September Rosemount 848LReference Manual 00809-0100-4696,Rev AA September Rosemount 848LReference Manual Reference Manual Physical Specifications Function BlocksSpecification Rosemount 848LReference Manual DIMENSIONAL DRAWINGSRosemount 848L 00809-0100-4696,Rev AA September Figure A-3.Rosemount 848L Wiring DiagramRosemount 848L Reference ManualReference Manual ORDERING INFORMATIONRosemount 848L Reference Manual Rosemount 848LLOCATIONS CERTIFICATES North American Approvals Appendix B Product CertificationsAPPROVED MANUFACTURING LOCATIONS EUROPEAN DIRECTIVE INFORMATION HAZARDOUSReference Manual European ApprovalsRosemount 848L Reference Manual Appendix C Function BlocksRESOURCE BLOCK PARAMETERS Rosemount 848LFREE SPACE Rosemount 848LReference Manual OUTPUT Rosemount 848LReference Manual Reference Manual ADVISE ENABLERosemount 848L 00809-0100-4696,Rev AA September I/O TRANSDUCER PARAMETERSRosemount 848L Reference ManualTRANSDUCER TYPE Rosemount 848LReference Manual OUT 3 TAG Rosemount 848LReference Manual 00809-0100-4696,Rev AA September LOGIC TRANSDUCER PARAMETERSRosemount 848L Reference ManualReference Manual DISCRETE INPUT BLOCKRosemount 848L Table C-4.Parameters Rosemount 848LReference Manual 00809-0100-4696,Rev AA SeptemberReference Manual DISCRETE OUTPUT BLOCK Supported ModesRosemount 848L Reference Manual MULTIPLE DISCRETE INPUT BLOCKSRosemount 848L 00809-0100-4696,Rev AA September Rosemount 848LReference Manual MULTIPLE DISCRETE OUTPUT BLOCKTable C-7.Parameters and Rosemount 848LReference Manual 00809-0100-4696,Rev AA SeptemberReference Manual Appendix D Logic Equation SyntaxRosemount 848L Table D-1.Supported Functions Rosemount 848LReference Manual 00809-0100-4696,Rev AA SeptemberPS channel number, divisor Rosemount 848LReference Manual Reference Manual ERROR HANDLINGTable D-2.Error Handling Rosemount 848LReference Manual EXAMPLESRosemount 848L Reference Manual Rosemount 848LRosemount 848L Appendix EMotor Control INTRODUCTION TO MOTOR CONTROLReference Manual VARIATIONS ON MOTOR CONTROLRosemount 848L 00809-0100-4696,Rev AA September Rosemount 848LReference Manual Reference Manual WRITING 848L EQUATIONS Basic Motor ControlRosemount 848L Reference Manual Interlock Permissive Emergency ShutdownRosemount 848L Reference Manual Restart DelayRosemount 848L Reference Manual Maximum RestartsRosemount 848L Reference Manual Winding TemperatureRosemount 848L Reference Manual Hand-Off-AutoRosemount 848L Reference Manual Intermediate StopRosemount 848L Reference Manual Redundant Motors - Alternate StartRosemount 848L Reference Manual Redundant Motors - Timed SwitchRosemount 848L 00809-0100-4696,Rev AA September Rosemount 848LReference Manual Reference Manual Redundant Motors - Switch on FailureRosemount 848L 00809-0100-4696,Rev AA September Rosemount 848LReference Manual E-16 Rosemount 848LReference Manual Rosemount 848L Appendix FValve Control INTRODUCTION TO VALVE CONTROLReference Manual Alarms Variations on Valve ControlRosemount 848L Reference Manual Boolean Expressions Basic Valve ControlRosemount 848L Reference Manual Open-Auto-Close Alarm VariationsOutput Variations Output with Interlock Rosemount 848LReference Manual Simple Valve Variations PermissiveRosemount 848L Reference Manual Double Block and BleedRosemount 848L Reference Manual Motorized Valve Heat Exchange Medium SelectionRosemount 848L Reference Manual Rosemount 848L00809-0100-4696,Rev AA 9/17/04 IndexRosemount 848L Reference Manual00809-0100-4696,Rev AA 9/17/04 Rosemount 848LReference Manual 00809-0100-4696,Rev AA 9/17/04 Rosemount 848LReference Manual Index-4 Rosemount 848LReference Manual Reference Manual ¢00809-0100-4697F¤