ELECTRICAL MAINTENANCE LOW AND MEDIUM

OVERVIEW

The backbone of many electric power systems is the medium voltage distribution system. Typically operating at voltages ranging from 2,400 to 34,500 Volts, voltage stress, corona, surges and protection of equipment all create unique challenges in design, equipment selection, operation and engineering. This 2 day class takes you through the basics of medium voltage power systems including components,equipment, design and operation problems as well as protection of medium voltage systems.

DESCRIPTION SUBJECTS

1. MEDIUM VOLTAGE SAFETY

v Electrocution at Low vs. Medium Voltage, Arc Flash,

v Qualified Person, Approach Boundaries

2. TYPES OF MEDIUM VOLTAGE SYSTEMS

v Utility and Industrial One lines, Reliability Requirements,

v Overhead and Underground Systems, Regulated Systems

3. MEDIUM VOLTAGE CABLE

v Copper vs. Aluminum Design, Voltage Ratings

v Insulation Ratings, 100%, 133%, 173% Insulation Levels,

v Shielding Requirements, Electric Fields, Terminating MV

v Conductors, Orientation of Overhead Lines

4. MEDIUM VOLTAGE SUBSTATION TRANSFORMERS

v Core and Coil Design, Aluminum and Copper Windings

v Tank Construction, Loss Evaluation, Efficiency, Regulation

5. SPOT NETWORKS

v Spot Network Design, Network Protectors, Network Protector

v Relay Operation, Directional Protection Requirements

6. PARTIAL DISCHARGE

v  Corona, Surface Tracking, Voltage Stress, Sensing Partial

v  Discharge, Component Failure

7.  GROUNDING MEDIUM VOLTAGE SYSTEMS

v Resistance Grounding, Solid Grounding, Ungrounded Delta

v Charging Current, Effect of Ground Faults on Delta Voltage

8. SURGE PROTECTION

v Lightning and Switching Surges, Classes of Surge Arresters

v MCOV Ratings - (Maximum Continuous Operating Voltage)

v TOV - (Maximum Temporary Over Voltage Capability),

v Protective Characteristics, Surge Arrester Selection, Energy

v Capability, Effect of Grounding on Arrestor Selection,

v Insulation Coordination,

9. CURRENT TRANSFORMER APPLICATIONS

v Ratings, Selection Process, Accuracy, Saturation, Excitation

v Curves, Burden Calculation, Momentary Ratings

10. MEDIUM VOLTAGE CIRCUIT BREAKERS

v Vacuum, Air, Oil, SF6 Designs, Symmetrical Interrupting

v Rating, K-Rated Voltage Factor, Close and Latch Capability

11. RECLOSERS

v Application on Feeder Circuits, Recloser Settings

v Continuous Current and Interrupting Ratings

12.  MEDIUM VOLTAGE FUSES

v Medium Voltage Switches, Load Rating, Close and Latch

v Rating, Short Time Rating, Expulsion vs. Current Limiting

v Fuse Characteristics, E and R Rated Fuses, Fuse Cutouts

13. MEDIUM VOLTAGE PROTECTION CONCEPTS

v Medium Voltage Protection, Relays, Circuit Breakers, R and

v E rated Fuses, Short Circuit vs. Overcurrent Protection

14. DISTRIBUTION FEEDER PROTECTION

v Protection with Fuses - 300%, Overcurrent Protection with

v Relays - 600%, Short Circuit Damage Characteristics, Relay

v “Reach” for End of Line Faults

15. ROTATING MACHINERY PROTECTION

v Requirements, Decrement Curves, Thermal Damage Curves,

v Reactive, Capability Curves, Differential Protection

16. MEDIUM VOLTAGE MOTOR CONTROLLERS

v Protection Requirements, Motor Management Relays, Circuit

v Breaker Protection, Relaying, Class R Rated Fuses

17.   TRANSFORMER PROTECTION

v ANSI C57 Thru Fault Curves, Impact of Transformer Winding

v Configuration, Overview of Differential Protection, Inrush and

v Harmonic Restraint

INSTRUCTOR

Tugino, ST, MT  and Team / Dr. Waluyo, MT and Team