PROPOSED CONSTRUCTION OF BUILDINGS AND INFRASTRUCTURE FACILITY
FOR FACAULTY OF TECHNOLOGY OF THE UNIVERSITY OF SRI
JAYAWARDHENAPURA, HOMAGAMA
SPECIFICATION
CONSTRUCTION AND COMPLETION OF THE PROPOSED BUILDING
COMPLEX AT PITIPANA HOMAGAMAPARTICULAR
PARTICULAR SPECIFICATIONS FOR LOW VOLTAGE
PANEL BOARDS
Contractor:
MAGA ENGINEERING (PVT) LTD,
No. 200, NAWALA ROAD,
NARAHENPITA.
Tel : 2808835-44 Fax : 2808846-47
Table of Contents
1. General ................................................................................................................................................ 2
1.1 Introduction. .................................................................................................................................. 2
1.2 Scope of Work .............................................................................................................................. 2
1.3 Technical Details .......................................................................................................................... 2
1.4 Regulations and Standards ............................................................................................................ 2
1.5 Rated Voltage and Frequency ....................................................................................................... 2
2. Technical Specifications ..................................................................................................................... 2
2.1 Enclosures ..................................................................................................................................... 2
2.2 Fusing Machanism ........................................................................................................................ 3
2.3 Switchgears ................................................................................................................................... 3
2.4 Busbar chambers and Busbars ...................................................................................................... 3
2.5 Iron Work and switch frame ......................................................................................................... 4
2.6 Mounting of Switchgears .............................................................................................................. 4
2.7 Internal Wiring .............................................................................................................................. 4
3. Identification and Labeling ................................................................................................................. 4
4. Energy Meters & Power Analysers ..................................................................................................... 5
5. Earth Fault Relays ............................................................................................................................... 5
6. Surge Protectors and Arrestors ........................................................................................................... 5
7. Current Transformers .......................................................................................................................... 5
8. LV Main Switch Board with Auto Transfer Switch ........................................................................... 5
9. Special Tests & Standards .................................................................................................................. 6
10. Warranty, Services & Defects Liability Period................................................................................. 6
1. General
1.1 Introduction.
Low voltage panel boards specified in here shall be fabricated and assembled in a factory, which is
specially built for that task and from a workforce specially trained for that purpose. Bidder shall
arrange factory visits up on request of the client to inspect the distribution boards prior to their
dispatch from the factory in several stages of the production. All material and switchgears shall be
long lasting and have a solid record of accomplishment in the industry.
1.2 Scope of Work
The scope within this specification shall comprise of fabricating, assembling, testing and delivery of
low voltage panel boards as per the single line drawings provided as annex 6. The product shall meet
with technical specification outlined here and shall comply with the relevant sections of British
Standards or IEC standards as well as the chapter 5 and chapter 7 of the CIDA SCA/8 publication as
applicable. Maintaining adequate stocks of spares for a period of two years commencing from the date
of invoice, is also a part of this scope.
Materials or items if found to be defective or malfunctioned, bidder shall replace those items at the
cost of his own, within three working days after notice by the client over a period of two years.
1.3 Technical Details
Addition to the technical details mentioned from 2.1 to 2.7, all materials, switchgears and accessories
should be long lasting and should hold the withstanding capability for Sri Lankan environmental
conditions such as heat, humidity etc. Bidder shall provide all the technical details for each item for
evaluations as well as the dully-filled data sheets given with the tender documents. The selected
bidder shall provide material samples for the approval of Engineer when required.
1.4 Regulations and Standards
Unless otherwise specified all materials and the work shall comply with the BSEN 60439-1, IEC
60439-1, IEC 664-1, BS 7671, IEC 60529 as and the chapter 5 and 7 of CIDA publication SCA/8.
1.5 Rated Voltage and Frequency
The rated voltage shall be 400/230 V, AC and the frequency shall be 50 Hz
2. Technical Specifications
2.1 Enclosures
Enclosure shall be provided to protect all equipment against external influences and to have a
protection against contact with live parts.
All enclosures shall be fabricated with pre galvanized mild steel sheets which the thickness is
selected according to size of the panel. The enclosure shall either surface mounted, flush mounted or
free standing as mentioned in the annex 2. Flush mounted boards shall be provided with suitable flush
plate or collar to mask the recess opening. All enclosures shall be powder coated both internal and
external surfaces with RAL9002 colour. Adequate spacing for internal wiring, cables, and ventilation
shall be kept according to the standards. All panels shall have a durable push button lock with a key to
prevent unauthorized access. The key shall be common to fit all locks provided on all panels delivered
to this project.
The successful bidder shall provide 3 liters of powder coated paint of the same colour as fabricated for
the touchup purposes in site works along with the delivery.
The selected bidder shall submit shop drawings for each panel board prior to the fabrication for the
approval of electrical engineer.
Enclosures shall comply with the IEC 60529 standard addition to fulfilling the above requirement.
Enclosures which will be installed in outdoor locations shall provide a degree of protection not less
than IP55 confirming to BS 5490 (SLS 963:1992).
All screw nails, nuts and bolts used for any purpose in this work shall be hot dipped galvanized or
stainless steel.
2.2 Fusing Machanism
MCB type fuses of suitable amperage shall be used for all low voltage fusing purposes for easy
maintenance and to minimize the down time in some cases.
HRC fuses of the standard type shall be used with surge protective devices in MDBs.
2.3 Switchgears
All switchgears shall comply with BS 3871, IEC 61439 and shall be designed to carry the rated
current continuously and the utilization category shall be AC22 unless otherwise specified. All
switchgears shall be fitted with a reliable indicating device, indicating the position of the moving
contacts if the contacts separation is not externally visible.
All switchgears shall be of one reputed brand and series such as Schneider, ABB, SIEMENS, GE,
EATON, Legrand, ALSTOM or equivalent.
2.4 Busbar chambers and Busbars
Busbar chambers shall be fabricated from sheet steel stiffened and braced as necessary and shall
generally comply with the requirements of BS 5486.
These shall be rust proof and provided with removable end, top and bottom plates.
The busbars shall be of copper or aluminium of adequate cross section and the design shall be such
that connection can be made by clamping without the necessity for drilling. Busbars shall be coloured
in their respective phase colour or encapsulated in insulation.
Busbars shall, in addition to being spaced at such intervals to give the necessary air clearance for the
voltage rating, be completely insulated in an approved manner. Primary busbars, connections and
their supports shall be capable of carrying the short circuit current associated with their short circuit
rating for a period of 3 seconds.
Busbars where installed shall be rated to withstand at any position the full fault level related to the
largest protective fuse that could be used with the main isolator.
2.5 Iron Work and switch frame
Mounting structures and frames shall be of steel. These shall be of sufficient size and strength to
ensure rigidity and freedom from vibration and rust proof.
2.6 Mounting of Switchgears
All switchgears shall be rigidly fixed or mounted on DIN rails and should be able to withstand the
normal thermal & mechanical stresses and dynamic stresses due to switchgear operation.
All switchgears shall be installed so as to ensure ease of operation and maintenance.
2.7 Internal Wiring
All internal wirings shall be done according to the standards by selecting proper cables of flexible
type. Coloured cable boots shall be used for each cable end for relevant phase. Termination of cable
shall be done using cable lugs or ferules as appropriate. Termination of bare copper fiber bunch to the
breakers or any other switchgear is not allowed.
Bidder shall select a cable brand from either Kelani or ACL.
3. Identification and Labeling
Labels shall be provided for all instruments and components mounted on the front of each control
panel. Within panels adequate labeling shall be provided using white letters “Helvetica Medium 24
PT” labeling shall be capital letters on the cover plates coated with hard varnish for all fuses, relays,
control equipment etc. Such labeling shall be correspond in detail with item numbers for additional
identification of equipment.
Where the operation of switchgear and control gear cannot be obtained by the operator and where this
might cause a danger, a suitable indicator, complying with BS 4099 where applicable shall be fixed in
a position visible to the operator.
Protective devices shall be arranged and identified so that the circuit protected may may be easily
recognized.
All panel boards shall carry a hard laminated single line diagram illustrating the technical functions
and circuit distribution, of a suitable size placed in the document holder or stick on the internal side of
the front door for small distribution boards. Addition to mentioned this diagram shall provide the
information mentioned under chapter 5, pg 34of the CIDA SCA/8 publication.
Every item of equipment or enclosure within which a voltage exceeding 250 volts exists and where
the pressure of such a voltage would not normally be expected, shall be so arranged that before access
is gained to live parts a warning of the maximum voltage present is clearly visible. Access should be
restricted by an appropriate transparent material on which the voltage underneath is clearly marked.
The standard type of electrical hazard warning with the level of voltage shall be provided on front
door of each distribution board engraved on Traffolyte or similar engraving laminate.
4. Energy Meters & Power Analysers
Energy measuring meters with data access/transferring capabilities through IP network shall be
provided in Main switch board of the premises as illustrated in the tender drawings. These shall be
equipped to store energy related data including power interruptions up to 60 days and shall be flush
mounted with the main panel door as per the approved shop drawing.
Power analyzers with data access/transferring capabilities through IP network shall be provided in all
building main distribution boards as mentioned in the tender drawings. The data storage capabilities
shall be same as the energy meters described above.
5. Earth Fault Relays
Earth fault relays to be of the core balance type with adjustable sensitivity and shall be fully
tropicalized. All over-current and earth fault relays shall be tested and calibrated to the satisfaction of
the Engineer and all costs connected with this shall be deemed to have been included in the tender
price.
6. Surge Protectors and Arrestors
Surge protective devices shall be installed on Campus main power distribution board and all the
Building main distribution boards. The protection class and the specifications shall be selected
according to the IEEE C62.72-2007 & IEC 801-5. Bidder shall provide the technical details of the
selected product to the reference of of electrical engineer along with the bid.
7. Current Transformers
Current transformers shall be selected and installed according to the IEC 44 for monitoring,
controlling and protection where required.
8. LV Main Switch Board with Auto Transfer Switch
Main switch board of the premises shall confirm to IEC 439, 1-3. The enclosure and switchgear
assembly should be designed to withstand mechanical stress in case of a severe fault condition. The
degree of protection of enclosures shall confirm to the IEC 529 and meet the specified requirements.
Automatic transfer switches shall be provided to allow automatic selection between the normal power
supply and the standby generator supply.
The automatic transfer switch shall consist of the following basic elements.
• A four pole motor operated, load break change over switch with a rocker arm _ moving
contact which makes it physically impossible to parallel the two sources of supply.
• Sensing / supervisory circuits to constantly .monitor the condition of power sources and to
provide the signal necessary for the switching of the automatic transfer switch.
• Transfer mechanism to effect change over the main contacts from source to source.
• Status indication to show which source of power the load is connected.
• Command signals to start and stop the standby diesel generator.
Failure to one or more phases of the incoming supply or a reduction in voltage to less than 80% (but
adjustable) of the rated range will constitute a failure. If the failure persists for more than 10 Seconds
(adjustable), the initiation to start the engine of the standby generator will be given and the load shall
be automatically disconnected from the normal supply and connected to the generator supply. After
restoration of the normal supply to more than 90% (but adjustable) of the rated voltage the automatic
transfer switch shall automatically be restored to its normal position after preset adjustable period of 0
to 5 minutes. A signal shall be initiated to stop the engine of the standby generator after a further 0 to 5
minutes (adjustable) unloaded running time.
9. Special Tests & Standards
The main switchboard of the premises and the main distribution boards of all buildings shall include
the following tests which shall be repeated in the presence of the client’s electrical engineer and
which shall be repeated if required.
(i) High voltage withstand test in accordance with BS 162
(ii) Operational tests of all equipment including interlocks and protection devices,
with simulation of all external circuit functions.
10. Warranty, Services & Defects Liability Period
Total delivery including all switchboards and distribution boards shall carry a minimum 2 years
warranty against fabrication and manufacturing defects except all types of MCCB’s above 800A
rating. MCCB’s above 800A shall carry a 3 years warranty for its proper functioning during that
period. The bidder shall arrange panel services in each year for main switchboard and main
distribution boards of all buildings during the 2 years defects liability period.
The Warranty & Defects Liability period will be started from the date we handover the project to
University of Sri Jayewardenepura.
The bidder shall submit the warranty letter along with the bid for the reference of the electrical
engineer.
