3 RMUs Presently Used What is an RMU? Who operates it? Are there safety concerns?
4 RMU OperationOpening/closing of the load break switch or earthing switch:Key/leverPushed to overcome spring forceTurn 90˚ at ~20 N.m (clockwise or counter-clockwise depending on usage)Who operates it?Are there safety concerns?Can it function remotely?
5 Project ObjectivesTo design a motorized retrofit for automatic operation of (F&G*) Ring Main Unit (RMU) as per technical specifications provided by TNB Distribution.
7 DeliverablesA prototype RMU Motorization Unit for operation of manually operated F&G* Ring Main Units.
8 Project ImpactThe proposed system would be able to switch the RMU breakers in a safe manner via remote control.Reduce downtime via remote operation and enhance the safety of TNB’s personnel by eliminating the need for manual operation of the RMU.
9 Project Methodology Stages of prototype development: Torque and dimension measurementsStudy of Actuation MechanismGrip frame design and material selectionSensors & AlignmentPower & ControlsTesting & Trials
10 RMU Automation Operational Block Diagram Auto/RemoteManual pushrelays &IndicatorsLocal/ManualCWLocal/ManualCCWM1Power Supply UnitMotor Driver w max current limitM228VDC 10ACW/CCWcontrol signalM3MicrocontrollerLoad switch limit switchSCADA
11 Components List Power supply unit Grip Frame Motor Mounting Rails AssemblyProgrammable Logic ControllerMotor Driver/controllerAuto/Manual Cam Selector SwitchPush Power RelaysLimit/position SensorsGeared DC MotorsMiscellaneous
12 FeaturesLight-weight (require only one person for mounting & installation)Simple gripping and holding mechanismReady for remote and local operationCompletely detachable motor unit for manual operationContinuous Breaker load switch status indicatorMotor over-current protectionResponse time of < 5 secondsMotor interlock operation
13 Estimated Costing* per 2+1 RMU (3 motor set) Mechanical works (motor mounting and grip frame) – ~ RM1300Geared motors – 3 x RM700Controller – RM400Motor driver – RM700Sensors and electronics components – RM400Power Supply Unit – RM900 (for prototype only)TOTAL COST – ~RM5000 (without PSU)* For large quantities of order
14 Initial survey and testing in ILSAS Load breaker switch sizingInitial motor selection
15 Continuation of motor selection Motor mount and torque testing