Danfoss VT2800 Series Design Manual

Contents

VLT ® 2800 SeriesProgramming416 Process units(REF/FEEDB. UNIT)Value:✭No unit (NO UNIT) [0]% (%) [1]ppm (PPM) [2]rpm (RPM) [3]bar (BAR) [4]Cycles/min (CYCLE/MI) [5]Pulses/s (PULSE/S) [6]Units/s (UNITS/S) [7]Units/min. (UNITS/MI) [8]Units/h (UNITS/H) [9]°C (°C) [10]Pa (PA) [11]l/s (L/S) [12]m 3 /s (M 3 /S) [13]l/min. (L/M) [14]m 3 /min. (M 3 /MIN) [15]l/h (L/H) [16]m 3 /h (M 3 /H) [17]Kg/s (KG/S) [18]Kg/min. (KG/MIN) [19]Kg/hour (KG/H) [20]Tons/min. (T/MIN) [21]Tons/hour (T/H) [22]Metres (M) [23]Nm (NM) [24]m/s (M/S) [25]m/min. (M/MIN) [26]°F (°F) [27]In wg (IN WG) [28]gal/s (GAL/S) [29]Ft 3 /s (FT 3 /S) [30]Gal/min. (GAL/MIN) [31]Ft 3 /min. (FT 3 /MIN) [32]Gal/h (GAL/H) [33]Ft 3 /h (FT 3 /H) [34]Lb/s (LB/S) [35]Lb/min. (LB/MIN) [36]Lb/hour (LB/H) [37]Lb ft (LB FT) [38]Ft/s (FT/S) [39]Ft/min. (FT/MIN) [40]Function:Select among different units to be shown on thedisplay. The unit is read out if an LCP controlunit can be connected, and if Reference [unit] [2]or Feedback [unit] [3] has been selected in oneof parameters 009-012 Display read-out, and inDisplay mode. The unit is used in Closed loopalso as a unit for Minimum/Maximum referenceand Minimum/Maximum feedback.Description of choice:Select the required unit for the reference/feed-back signal.■ VLT 2800 RegulatorsThe VLT 2800 has two integrated PID regulators, oneto regulate speed and one to regulate processes.Speed regulation and process regulation requirea feedback signal back to an input. There are anumber of settings for both PID regulators that aremade in the same parameters, but selection ofregulator type will affect the selections that haveto be made in the shared parameters.In parameter 100 Configuration it is possible to selectregulator type, Speed regulation, closed loop [1]or Process regulation, closed loop [3].Speed regulationThis PID regulation is optimised for use in applicationsin which there is a need to maintain a particular motorspeed. The parameters that are specific for the speedregulator are parameter 417 to parameter 421.Process regulationThe PID regulator maintains a constant processmode (pressure, temperature, flow, etc.) andadjusts the motor speed on the basis of thereference/setpoint and feedback signal.A transmitter provides the PID regulator with afeedback signal from the process as an expressionof the process’s actual mode. The feedback signalvaries as the process load varies.This means that there is a variance between thereference/setpoint and the actual process mode.This variance is compensated by the PID regulatorby means of the output frequency being regulatedup or down in relation to the variance between thereference/setpoint and the feedback signal.The integrated PID regulator in the frequency converterhas been optimised for use in process applications.This means that there are a number of specialfunctions available in the frequency converter.Previously it was necessary to obtain a systemto handle these special functions by installingextra I/O modules and programming the system.With the frequency converter the need to installextra modules can be avoided. The parameters✭ = factory setting. () = display text [] = value for use in communication via serial communication portMG.28.E9.02 - VLT is a registered Danfoss trademark 99