Power Center Factory

Basic of LV Switchboard (IEC-61439-2)

Presented by yEng. Nooruddin Khan

18 Dec 2013

Switchboard: Definition? A Switchboard is a point in an electrical network at which an A Switchboard is a point in an electrical network at which an

incoming-power supply divides into separate circuits, each of which is controlled and protected by the fuses or switchgear of the switchboardswitchboard.

Switchboard: A distribution switchboard is divided A distribution switchboard is divided

into a number of functional units, each comprising all the electrical and mechanical elements thatand mechanical elements that contribute to the fulfillment of a given function. It represents a key li k i th d d bilit h ilink in the dependability chain.

Distribution switchboards are Distribution switchboards are critical to the dependability of an electrical installation. They must comply with well-defined standards Picture: Switchboard panel with open-type comply with well-defined standards governing the design and construction of LV switchgear assemblies

knife switches is an Edison DC type. from The Frick Power House, 1904 A.D.

assemblies.

Switchboard Parameters:

Rated Operational Voltage (Ue) : This is the maximum continuous voltage at which equipment may be used.

Rated Insulation Voltage (Ui) : The highest operating voltage that will not cause a dielectric strength failure. The rated insulation voltage is used as a parameter for dielectric strength tests and forvoltage is used as a parameter for dielectric strength tests and for the creepage distance. The rated insulation voltage must always be higher than the rated operating voltage (Ue).

Rated Impulse Voltage (Uimp) : The peak value of an impulse voltage of which the circuit of an assembly is capable of withstanding without failurewithstanding without failure.

Rated current (In) : Maximum current that the device can carry continuously without abnormal temperature risecontinuously without abnormal temperature rise.

Switchboard Parameters:

Rated short time withstand current (Icw) : Maximum short time withstand current that the equipment can carry without damage.

Rated Peak withstand current (Ipk) : The rated peak withstand current of a circuit of an assembly is the value of peak currentcurrent of a circuit of an assembly is the value of peak current assigned to that circuit by the manufacturer which that circuit can withstand satisfactorily.

Rated short-circuit making capacity (Icm) Maximum current (peak) a device can make at its rated voltage according to the (p ) g gconditions of standard. Devices without protection like switches, must be able to withstand short-circuit current with a value & duration resulting from action of the associated protection device.duration resulting from action of the associated protection device.

Switchboard Parameters:

Rated ultimate short-circuit breaking capacity (Icu) : This is the maximum short-circuit current value that a circuit breaker can break t i lt d h l ( ϕ) Th t t t dat a given voltage and phase angle (cos ϕ). The tests are executed

according to the sequence O - t - CO. O represents an automatic break operation, t a time interval and CO a make operation followed by an automatic break operation. Following the test, the circuit breaker must continue to provide a minimum level of safety (isolation, dielectric strength).( g )

Rated service short-circuit breaking capacity (Ics) : This is the al e e pressed as a percentage of Ic It ill be one of thevalue expressed as a percentage of Icu. It will be one of the

following values: 25% (category A only), 50%, 75% or 100%. The circuit breaker must be capable of operating normally after breaking the Ics current several times using the sequence O-t-CO-t-CO.

LV Switchboard: Standard International Standard IEC-61439-1 & 2 (Old Standard IEC-60439-1 International Standard IEC 61439 1 & 2 (Old Standard IEC 60439 1

is still valid for KSA market till 2014). Certified switchboard is called “Verified assembly” or in old std. “Type Tested Assembly”

American Standard ANSI-C37.20.1 or IEEE, UL-508 (Out of Power Center Scope) p )

MV Switchgear: Standard

IEC-61439-2: Verification

Switchboard: Customer Inquiry Customer send his inquiry in different ways(1) Single Line Diagram (Example)

Switchboard: Customer Inquiry(2) Load Schedule (Example)

Switchboard: Customer Inquiry(3) Main/Branch CB Size Listing (Example)

Switchboard: Customer Inquiry(4) Drawings (Example)

Specification: Additional information with inquiry: Customer specification should

be attached with SLD/Schedule/drawing etc.

Request For Quotation (RFQ) Please send all inquiry

to PC with filled RFQ.

Switchboard: Main Components

Housing (Enclosure)

Bus-bar

Incoming CB/Fuse/Switchg

Outgoing CB/Fuse/Switch

Metering & Indication

Control & Accessories etc Control & Accessories etc.

Housing (Enclosure)

Enclosure: Function?

Protection of switchgear, i t h i l i tagainst mechanical impacts,

vibrations and other external influences (EMI, dust, moisture, vermin, etc.)

The protection of human life The protection of human life against the possibility of direct and indirect electric

Enclosure: Selection Criteria Application: Indoor/Outdoor

Degree of Protection: IP Rating, IP-31, IP-42 or IP-55g g, ,

Mechanical Strength (IK) Rating

Material: Mild Steel/Stainless Steel/Polyester/GRP

Certification: Type Tested/Universal Certification: Type Tested/Universal

Form of Separation: Form-1/2a/2b/3a/3b/4a/4b

Entry: Top/Bottom

Access: Front/Rear

IP Rating as per IEC-60529

IK Rating as per IEC-62262

Form of Separation:

Bus-bar Bus bar is a conductor of electricity e.g. strip or bar of copper, brass

or aluminum that conducts electricity within a switchboard, distribution board substation battery bank or other electricaldistribution board, substation, battery bank or other electrical apparatus etc.

Cu-ETP (Electrolytic-Tough-Pitch) R240 grade of bus bar is specified in switchboard application as per EN 1650

Bus-bar Selection Criteria Thumb Rule: 1.5A/mm2 (Not Accurate & just for rough estimation)

S l t it bl i f t bl d l d b CDA Select suitable size from tables developed by CDA.

Tables Developed by switchboard manufacturers Tables Developed by switchboard manufacturers

Using Formula

Using Software

Switchgear & CB A Switchgear is the combination of electrical disconnect switches,

fuses or circuit breakers used to control, protect and isolate electrical equipment

A Circuit Breaker is a manually or automatically operated electrical switch designed to protect an electrical circuit fromelectrical switch designed to protect an electrical circuit from damage caused by overload or short circuit.

Overload Protection

Short Circuit Protection

Insulation Fault Protection

Electrical Hazard

LV & MV Switchgear

Type of LV Circuit Breaker There are three types of LV Circuit Breakers in market

1 MCB (Miniature Circuit Breaker) in two frame size upto 63A/upto1. MCB (Miniature Circuit Breaker) in two frame size upto 63A/upto120A (Schneider Electric iC60 & iC120 range)

2 MCCB (Molded Case Circuit Breaker) available normally upto2. MCCB (Molded Case Circuit Breaker) available normally upto1600A (Schneider Electric MCCB NSX/Easypact range upto 630A & NS from 630A upto 3200A)

3. ACB (Air Circuit Breaker) available upto 6300A (Schneider Electric NT range upto 1600A & NW range upto 6300A)

Selection Criteria of LV CBWhat are the characteristics for choosing a circuit breaker? Current parameter: In – Icu – Ics – Icm

Voltage parameters: Ue – Ui – Uimp

Fixed or withdrawable

Standard

T f t i it Type of trip unit

Number of poles

Need for discrimination

Metering & Indication Lamps

Normally Metering consists of Digital multimeter or Analog Ammeters & Voltmeters 72X72 or 96X96 size with selector switch, Current transformers & control fuses/fuse holders

Indication Lamps consist of three in Indication Lamps of 22mm Indication Lamps consist of three in Indication Lamps of 22mm diameter with Red/Yellow/Blue colors for all phases

Types of Switchboard

Switchboard or Main Distribution Board (Example: Blokset, Prisma Plus-P)

Motor Control Center (Example: Blokset, Prisma Plus-P) Panelboard or Sub Main Distribution Board (Example: Prisma

Plus P & GPlus-P & G Loadcenters or Final Distribution Board (Example: Prisma

Pack, Disbo)

Technology in Switchboard

Traditional distribution switchboards: Switchgear and fuse gear, etc. are normally located on a chassis at the rear of the enclosure. Required careful designing having knowledge of dimension of all components. (Example: Universal Enclosure panels)p )

Functional distribution switchboards: Made up of functional d l th t i l d it h d i t th ithmodules that include switchgear devices together with

standardized accessories for mounting & connections, ensuring a high level of reliability & a great capacity for last-minute and future changes.

Product Range Switchboards up-to 6300A & up-to Form-4b Panel-boards

L d C t Load Centers MCC (DOL/Y-∆/VFD/Soft-starter) Auto & Manual Synchronizing Panels Auto. & Manual Synchronizing Panels ATS & MTS Lighting Control Panels PFC Panels (Capacitor Bank)

Product Characteristics

Designing Tools (Software)E di l f di i d f l i l k Ecodial for coordination study of electrical network

Rapsody for design Prisma Plus switchboard Rapsody for design Prisma Plus switchboard.

Schneider online “Electrical Calculation Tools”

Basic Calculation

Basic Calculation

Basic Calculation

Questions

Thank You