The document discusses the design and practice of switchgear according to IEC 61439, covering topics including definitions, types, functions, and components of switchgear, as well as circuit breakers and arc control techniques. It highlights the importance of switchgear in electrical energy management systems, provides criteria for selecting low voltage switchgear, and details the project specifications for the Al-Hamool water treatment plant. Additionally, it covers power factor correction benefits, switchgear testing, and skills acquired during the project.

1. Switchgear Design
Theory & Practice
IEC 61439
BY:
ENG/AHMED SAADA
ZAGAZIG UNIVERSITY.
FACULTY OF ENGINEERING.
Electrical power and Machines department.

2. Contents
 Introduction.
 DefinitionofSwitchgear.
 Types ofSwitchgear.
 Switchgearfunction.
 Ingress Protection.
 Switchgearcomponents.
 CircuitBreaker.
 TheArc.

3. Contents
 Arc ControlTechniques.
 Switchgeartests IEC439.
 ChoosingL.V Switchgear.
 PowerFactorCorrection.
 Al-HamoolW.T.P.
 SelectingComponents.
 ProjectOutcomes andShop drawing.
 SkillsAcquiredduring Project.

4. Introduction
• Electrical energy management system ensures supplyof energy to every
customers at all time at rated voltage, rated frequency and specified wave
form.
• Switchgear, protection and network automation are integral part of modern
energy management system.

5. Definition of Switchgear
• A switchgear or electrical switchgear is a generic term
which includes all the switching devices associated
with mainly power system protection. It also includes
all devices associated with control, metering and
regulating of electrical power system.

6. Types of Switchgear
Metal clad switchgear .
Metal enclosed.

7. Switchgear (depending on voltage)
1) Low voltage switchgear:
-Panel boards.
-Distribution switchboard.
-Main Distribution Board (MDB).
-Motor Control Center (MCC).
2) Medium voltage switchgear:
-Distribution board.
-Motor control center (MCC).
3) High voltage switchgear

10. Switchgear function
• Protection.
• Control.
• Measurement.
• Switching.
• Earthing.

11. Switchgear (location of installation)
• Indoor .
• Outdoor.

12. Ingress Protection (IEC 60529)
It specifies an international classification for the degrees of
protection provided by enclosures of electrical equipment against
the intrusion into the equipment of foreign bodies (i.e., tools, dust,
fingers and moisture).
EX:

13. Switchgear components
Switching devices.
Protection devices.
Measuring devices.
Bus bar connections throughout switchboard.
means of connecting a main cable to each unit.

14. Switchgear components
Enclosure.
Circuit Breaker.
Incomer.
Fuses.
Disconnectors.
Bus bar.

15. Circuit Breaker
IEC 60947
A device designed to open and close a circuit.
Components of C.B:
-A frame. -Contacts and operating mechanisms.
-Trip Units. -A method to extinguish an Arc.
-A method for mounting.
-Compliance with specific standards.

16. Circuit Breaker
IEC 60947
C.B Frame:
Two types:
-Metal frame. -Moulded frame.
 Contacts:
Provide a method for connecting the circuit with the system. A
contact set contains a fixed and movable contact. As a circuit
breaker opens or closes, the fixed contact maintains its position
while the movable contact moves to close (make) or open
(break) the circuit.

17. C.B Types.
ACB.
MCCB.
MCB.

18. C.B Types.
MCB

19. C.B selection
Basic criteria
1-Rating (U-I). 2-Breaking Capacity. 3-Number of poles.
4-IEC947 standard. 5-Type of load to be protected.
Continuity of service criteria:
1-Selectivity. 2-Withdrawability. 3-Maintainability
Comfort criteria:
1-Simple to install. 2-Easyto work with. 3-Accessories.

20. THE ARC

21. Arc in Circuit Breaker
What is arc ?
During opening of current carrying contacts in a
circuit breaker the medium in between opening
contacts become highly ionized through which the
interrupting current gets low resistive path and
continues to flow through this path even the
contacts are physically separated. During the
flowing of current from one contact to other the path
becomes so heated that it glows.This is called arc.

22. Arc Control
Techniques.

23.  -Stretching Arc.
 -Breaking Arc into Smaller Pieces.
 -Blowing Out Arc.
 -The arc chute method.
 -Enclosing Contacts.
 -The vacuum interrupter method.
 -The SF6 method.
 -The magnetic coil method.
 -The puffer method.

24. Switchgear tests IEC439
Type tests:
 Temperature rise limit.
 S.C withstand.
 I.P.
 Dielectric test.
 Protective circuit efficiencies.
 Mechanical operations.
 Clearances and creep age distances.
Routine tests:
 Functional test.
 Visual inspection.
 Dielectric test.

25. Choosing L.V Switchgear
 Purpose of usage. (Functionality).
 Ampere rating.
 Voltage rating.
 S.C withstand.
 I.P take in consideration (indoor or outdoor).
 Design concept.
 C.B.

26. Power Factor Correction
Causes of low power factor:
- Most of the motors used in industries are of induction type,
which have low lagging pf.
- High intensity discharge lamps operate at low lagging pf.
- Transformers system work at lagging pf.
- Load on the system is varying which results in decreasing or
low pf.
Why improve power factor?
The benefits that can be achieved by applying the correct power factor
correction are:
1-Environmental benefit. Reduction of power consumption due to improved
energy efficiency. Reduced power consumption means less greenhouse
gas emissions and fossil fuel depletion by power stations.
2- Reduction of electricity bills
3-Extra kVA available from the existing supply.
4-Reduction of I2R losses in transformers and distribution equipment.
5-Reduction of voltage drop in long cables.
6-Extended equipment life – Reduced electrical burden on cables and
electrical components.

27. Power factor correction panel

28. The Project
Al-Hamool W.T.P

29. Al-Hamool W.T.P
 Project Specifications:
Consulting Engineering Bureau “UTILITIES”
 General Switchgear requirements:
Ambient temperature 45 oc.
M.T&L.T boards.
J=1.6 A/mm2.
Frame thickness=2mm.
Detailedschematic connectiondiagrams and catalogues
 Bus bars:
Single system.
Copper with ample C.S.A.
 Circuit Breakers:
WithdrawableCB above 400 A.

30. Al-Hamool W.T.P
P-TR -SHORT CIRCUIT.
-OVER CURRENT.
-PHASE SEQUENCE / PHASE FAILURE.
M-TR -PHASE CURRENT.
-VOLTAGE.
-KWH METER.
-KVAR METER.
P-GEN -SHORT CIRCUIT.
-OVER CURRENT.
-PHASE SEQUENCE / PHASE FAILURE
/ (UNDER/OVER VOLTAGE).
-REVERSE POWER.
-UNDER/OVER FREQUENCY.
M-GEN -PHASE CURRENT.
-VOLTAGE.
-POWER FACTOR METER.
-FREQUENCY METER.

31. Al-Hamool W.T.P
M-CAP -PHASE CURRENT.
-VOLTAGE.
-KVAR METER.
P-MOT -SHORT CIRCUIT.
-OVER CURRENT.
P-OUT -SHORT CIRCUIT.
-OVER CURRENT.
P-INC -SHORT CIRCUIT.
-OVER CURRENT.
M-INC -PHASE CURRENT.
-VOLTAGE.

32. Selecting Components

33. Project Outcomes
and
Shop drawings

34.  S.L.D
 FRONT VIEW.
 WITH DOOR VIEW.
 CONTROL DIAGRAMS.
- star-delta connection.

35. Skills Acquired during
Project
 Auto CAD software.
 Using Catalogues.
 International Standards Knowledge.
 Scientific writing and reports preparing.

36. THANK YOU