Number Description26 Outputs UDC activeTable 3.2 Relay Control Functions3.3 MonitoringThe SAB monitors the voltages and currents in the inputand output lines, for example the auxiliary line and theDC-link, so that a phase loss or other errors can bedetected. These values provide detailed information on thecurrent load. The information is available via the fieldbus,the LCP, and the ISD Toolbox.The SAB monitors the signals detailed in Table 3.3 andprovides the measured values via the fieldbus and the LCP.Signal name DescriptionDC-link voltage DC-link voltageWarning code Warning codeError code Error codeTemperature control card Temperature control cardTemperature power card Temperature power cardTemperature SAB card Temperature SAB cardExternal encoder position External encoder positionExternal encoder speed External encoder speedUDC 1 current Current flow on DC-link line 1UDC 2 current Current flow on DC-link line 2AUX line 1 current Current on AUX Line 1AUX line 2 current Current on AUX Line 2AUX line voltage AUX line voltageBrake chopper gate Brake chopper gateBrake chopper feedback Brake chopper feedbackUDC Over-Inrush UDC current over-inrushUDC Bypass-Inrush UDC Current bypass-inrushUDC back current Current (link voltage) back fromthe servo drivesInrush relay power card Inrush relay power cardInrush relay SAB card Inrush relay SAB cardDC leakage current DC leakage currentBrake resistor powermonitoringBrake resistor power monitoringDC link total current DC link total currentDC link total current raw DC link total current (unfiltered)UDC 1 flow (filtered) UDC 1 current readoutUDC 2 flow (filtered) UDC 2 current readoutControlword ControlwordTable 3.3 Signals Monitored by the SABUse the ISD Toolbox Scope subtool to perform a trace onthese signals. If the overload situation is critical, the SABprotects itself and the servo drives by shutting down toprevent any damage. In such cases, warnings may not bevisible if the shutdown occurs quickly.3.3.1 AUX OutputThe SAB protects the servo drives connected to the AUXlines against overcurrent, overvoltage, and undervoltage. Ifan overload occurs, the outputs are disabled and an alarmis issued. If the UDC outputs are enabled, they are disabledfirst.For overvoltage and undervoltage conditions, anassociated warning with a different threshold is triggeredbefore the error. Set a user current limit in steps of 0.1amperes for each of the auxiliary lines in object 0x2003,sub-indexes 4 and 5 (see chapter 8.5 Object 0x2003: UAUXRelated Values). If this limit is reached, the SAB disables theauxiliary lines. If the current reaches 90% of the limit set, awarning is issued. The SAB has additional hardwaredetection/protection in case a hard short circuit occurs onthe auxiliary lines.3.3.2 DC OutputThe SAB protects itself and the servo drives connected tothe UDC lines against overcurrent, overvoltage, andundervoltage. If an overload occurs, the outputs aredisabled and an alarm is issued.For overvoltage and undervoltage conditions, anassociated warning with a different threshold is triggeredbefore the error. The SAB provides short-term overloadcapabilities; it is possible to run at 160% load for 60 s.However, afterwards, the SAB must run at a reducedoutput load to compensate the overload. The SAB has aninternal monitoring logic for the overload condition and itsduration.3.3.3 Brake Control and MonitoringConnect a brake resistor to the SAB to limit the UDCvoltage when the connected servo drives are inrecuperation mode and acting as a generator. Ifconfigured, the SAB limits the UDC voltage by connectingthe resistor via an internal IGBT switch. To monitor thefunctionality of the brake, the brake circuitry, and thebrake power dissipation, make the following settings:• Enter the correct resistance in object 0x2031 (seechapter 8.11 Object 0x2031: Brake Resistor).• Enter the correct power limit in object 0x2032(see chapter 8.12 Object 0x2032: Brake ResistorPower Limit).If any configured limit is overstepped, the SAB issues awarning or alarm. If configured to report an alarm, the SABtransitions to fault state. Reinitialize the SAB using theerror recover command in the SAB state machine.Servo Access Box (SAB) Oper... VLT® Integrated Servo Drive ISD® 510 System92 Danfoss A/S © 01/2017 All rights reserved. MG36D10233
