Prototype Development ofAutomated Ring Main Unit SystemTNB Distribution Presentation Meeting

Project Background

RMUs Presently Used

•What is an RMU?•Who operates it?•Are there safety concerns?

RMU Operation

• Opening/closing of the load break switch or earthing switch: Key/lever Pushed to overcome spring force Turn 90˚ at ~20 N.m (clockwise or

counter-clockwise depending on usage)

• Who operates it?• Are there safety concerns?• Can it function remotely?

Project Objectives

•To design a motorized retrofit for automatic operation of (F&G*) Ring Main Unit (RMU) as per technical specifications provided by TNB Distribution.

Customer Requirements

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Deliverables

•A prototype RMU Motorization Unit for operation of manually operated F&G* Ring Main Units.

Project Impact

•The 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.

Project Methodology

Stages of prototype development:1. Torque and dimension measurements2. Study of Actuation Mechanism3. Grip frame design and material selection4. Sensors & Alignment5. Power & Controls6. Testing & Trials

RMU Automation Operational Block Diagram

M1

M2

M3

Manual pushrelays & Indicators

Microcontroller

Motor Driver w max current

limit

28VDC 10A

SCADA

Auto/RemoteLocal/Manual

CWLocal/Manual

CCW

Load switch limit switch

Power Supply Unit

CW/CCWcontrol signal

Components List

1. Power supply unit2. Grip Frame3. Motor Mounting Rails Assembly4. Programmable Logic Controller5. Motor Driver/controller6. Auto/Manual Cam Selector Switch7. Push Power Relays8. Limit/position Sensors9. Geared DC Motors10.Miscellaneous

Features1. Light-weight (require only one person for

mounting & installation)2. Simple gripping and holding mechanism3. Ready for remote and local operation4. Completely detachable motor unit for manual

operation5. Continuous Breaker load switch status

indicator6. Motor over-current protection7. Response time of < 5 seconds8. Motor interlock operation

Estimated Costing* per 2+1 RMU (3 motor set)•Mechanical works (motor mounting and

grip frame) – ~ RM1300•Geared motors – 3 x RM700•Controller – RM400•Motor driver – RM700•Sensors and electronics components –

RM400•Power Supply Unit – RM900 (for prototype

only)•TOTAL COST – ~RM5000 (without PSU) * For large quantities of order

Initial survey and testing in ILSAS

Initial motor selection

Load breaker switch sizing

Motor mount and torque testing

Continuation of motor selection

DC Motor on mount

Testing torque capability

A closer look at the Motor Mounting Rail Assembly

Further testing on actual F&G RMU

Procurement of Test Bed RMU

Installation of Mount on Grip Frame

Motor mount installed on grip frame on an F&G RMU

Rear view of gripping clamp

F&G ZZTT and ZZT RMUs in UNITEN

ZZT F&G RMU ZZTT F&G RMU

Grip Frame

Detachable Motor Mounting Rail Assembly

Motor Selection and Testing – ILSAS

30VDC Circuit Breaker Motor

Gearbox Failure – Specified Torque 25N-m

Switching Key Failure

Testing on RMUs in UNITEN

Play Video

Motor Mounting Rail Assembly

Play Video

Motor Mounting Rail Assembly

Thank you.

Questions & Discussions

TimelineMonth 1 Month 2 Month 3 Month 4

Actuation Mechanism Assy

Fabrication and assy

Test and Trials

Cross Slide Traversing Assy

Design and Procurement

FabricationActuation and

Cross slide integration

Test and Trials

Sensors & Alignment

Selection Procurement Integration Test and Trials

Power & Controls System

Selection and Procurement

Programming Test and Trials

Networking and Communication

PDSB

Uniten Procurement Procedures

QuotationValue: ≤ RM 100 KFloat period: 3 - 14 daysMin. : 3 companies

TenderValue: > RM 100 KFloat period: 14 - 21 daysMin. : 5 companies