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HIMCHAL PRADESH STATE ELECTRICITY BOARD LIMITED ( A State Govt. Undertaking)
“NOTICE INVITING TENDER”
Sealed item rate tenders are herby invited on behalf of the Chairman cum
Managing Director HPSEB Ltd. by the undersigned from the approved / experienced contractor of
appropriate category for the execution of works as per the detail of works mentioned hereinafter.
The tenders shall be received on prescribed forms clearly super -scribed with Tender No. and Date
of opening together with earnest money in the office of Superintending Engineer, Operation
Circle, HPSEB Ltd. Solan, on stipulated date and time & will be opened in the presence of the
contractors or their authorized representatives who may wish to be present.
The tender document can be had on any working day during 11:00 AM to 5:00
PM w.e.f 1.06.2011 to 13.06.2011 from the office of Superintending Engineer, Operation Circle,
HPSEB Ltd. Solan against the payment as shown against the work in shape of demand Draft
payable at Solan in favour of Sr. Executive Engineer, Electrical Division HPSEB Ltd. Solan.
Name of Work Estimated cost
Earnest Money
Complet-ion Period
Cost of Tender Document
Sale of Tender Document
Receipt of Bids
Opening of Bids
Name of work: - Supply of Power
to ESIC Hospital
Katha Under ESD
Barotiwala.
(S.H.) “Survey, Design,
Supply, Erection,
testing &
commissioning of
11 KV HT line
with AB cable 3
core 240mm S.q.
Rs.
2083965/-
Rs.
52100/-
2
Months
Rs.1000/-
+8% Sales
Tax =
1080/-
1.06.2011
to
13.06.201
1 (4.00
PM)
14.06.201
1 (11.00
AM)
14.06.2011
(3.00 PM)
Before issue of the tender documents, the bidder shall have to
furnish adequate documentary evidence in support of qualifying
requirements stipulated as below:-
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1. CATEGORY-I:- The bidder/ Joint Venture Firms having A-Class License from Chief Electrical Inspector of any state/ union territory of India other than Himachal Pradesh, but they will have to register with CEI to HP within 2 months of the award. The Bidder shall be financially sound and average annual turnover of the bidder for the past 2 years, out of last 5 years should be Rs.1.0 Crore. As a proof of turnover the bidder shall have to produce a certificate from the Bank/ Chartered Accountant. The Bidder should have designed, erected and commissioned 3.00 Kms 11 KV HT line with AB cable and it should be in successful operation for the last two years at the time of sale of bid documents.
2. CATEGORY-II:-The Bidder/ joint venture Firms having A-Class
License from Chief Electrical Inspector, H.P. and having registered office in H.P. The Bidder should be financially sound and average turnover of the bidder for the past 2 years, out of last five years should be Rs. 1.0 Crore. As a proof of turnover the bidder shall have to produce a certificate from the Bank/ Chartered Accountant. The Bidder should have designed, erected and commissioned at least 3.00 KM 11 KV HT Line with AB cable and it should be in successful operation for the last two years at the time of sale of bid documents.
3. CATEGORY-III:- Bidder/ Association of retired employees of HPSEBL
having A-Class License from Chief Electrical Inspector, H.P. The bidder should have been in technical services of HPSEB for at least 20 years and in this regard certificate from HPSEBL’s serving Engineer not below the rank of S.E. shall have to be produced along with the list of works operated. However, the bidder/ any member of the association should not have been retired within 2 (Two) years of active service of the Board from the date of bidding. The bidder shall supply an asset statement equivalent to 30% of the Estimated Cost, at the time of purchase of tender duly certified by the Scheduled Bank/ Co-Operative Bank or C.A.
4. The Bidder should have Income Tax/ Sales Tax (VAT)/ CST/ Service Tax/ Employees Provident Fund registrations as required under Rules.
5. The bidder will declare on Non Judicial Stamp Papers that he is not
Black Listed by any State or Central Govt. Agency/ Department. Contd. Page-3
Page-3
6. The Earnest Money shall be received in shape of demand draft payable at Solan in favour of Sr. Executive Engineer, Electrical
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Division, HPSEBL, Solan. The EMD available against other works will not be transferable to this tender.
7. The detailed terms and conditions can be seen in the tender
documents.
8. If the date of receiving/ opening of the tenders happen to be a holiday,
the tender will be received/ opened on the next working day. 9. The bid documents are not transferable and cost of bid documents is
not refundable under any circumstance.
10. Telegraphic tenders and tenders without Earnest Money will not be
accepted. 11. Undersigned reserves the right to reject any or all the tenders without
assigning any reason and no contractor shall be allowed to put up the tender after stipulated date and time.
12. Undersigned reserves the right to increase/ decrease the quantum of
work as per requirement at site.
Superintending Engineer,
(Op) Circle, HPSEBL Solan.
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OPERATION CIRCLE, HPSEBL, SOLAN-173211 (H.P)
PART-I Technical Bid (Vol-I)
Tel. No. 01792-221481 Tele. Fax: 01792- 223652
PROVIDING ADDITIONAL 11 KV FEEDER FROM 220/66/11 KV S/STN. KATHA
TO KAILASH VIIHAR UNDER ESD BADDI DISTRICT SOLAN (H.P.)
Sub-Head:- Erection of 11 KV HT line by laying 11 KV XLPE cable 3 core 300MM
Sq in cable trench.
Package-1:- Erection of 11 KV HT line by laying 11 KV XLPE cable 3 core 300mm Sq in
cable trench = 1.6 KM .
BID No. – HC-II-DB-TENDER-10- DATED 10.Feb.2010
Superintending Engineer,
(Op) Circle, HPSEBL, Solan.
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SECTION-I
CIRCLE:- (Operation Circle, HPSEBL Solan )
DIVISION:- ( Electrical Division, HPSEBL Baddi.)
1. Standard:- All the material and equipment shall comply in all respect with the latest standard
or any other equivalent standards. The standards to which equipments offered shall be
stated in the bid.
2. Safety Margin in Design:- The design, dimensions and material of all parts shall be such that they shall not
suffer damage under most adverse conditions.
3. Electricity Rules-III All design and works pertaining to the supplies and installation of the
specifications shall confirm to the various rules in force under Electricity Act, Rules and
other legislations / regulations applicable at the place of the site .
4. Technical Deviations:- The bidders shall make his offer in consonance with the specified requirements.
In case the bidder wishes to depart from specifications in certain respects without
affecting the basic functional requirements or stipulations he shall submit a complete and
item wise list of such deviation / departure together with full particulars of the reasons for
the departures, in a separate schedule with reference to sections and paragraph numbers
of the bid document. The deviations shall be considered valid only in case the purchaser
has accepted the same formally. In the absence of such acceptance the equipment offered
shall be deemed to comply in every respect with these specifications.
The bidder, however, is free to offer special devices or equipment with a view ti
increase the performance / efficiency and life of the plant and minimize the initial cost or
maintenance cost of the equipment as a whole.
5. EXTRA WORKS:-
In case it is felt necessary , the purchaser may modify the quantitative
requirements in respect of equipment and related works and services of the bid
specifications at any time prior to the placement of order or subsequently, and the
supplier shall be bound to accept the same. Quantitative modifications shall, however be,
to a limited extent only. The prices shall be subject to adjustment for any specific
quantative modifications thus made.
The supplier shall , when asked in writing by the purchaser , supply the extra
quantity, perform extra work / furnish extra material not covered by the specifications or
included in the schedule but otherwise forming an inseparateable part of the work
contracted for or whose supply is considered essential by the purchaser. Extra payments
for such equipment, work or materials shall be applicable which shall be mutually agreed
upon and sorted out in advance between the supplier and the purchaser.
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6. GAURANTEES.
The contractor shall guarantee among other things the followings.
(a) Quality and strength of material used.
(b) Adequate factor of safety for all parts of equipment to withstand the mechanical
and / or Electrical Stresses developed therein.
© Suitability of design and workmanship of the equipment for the conditions
prevailing in the area.
(d) Satisfactory erection and commissioning of the equipment at site.
(e) The efficiency, temperature rise and other performance data prevailing in the area
for equipment as applicable in accordance with relevant standards & provisions for these
specifications.
(f) The delivery periods given in the bid.
It must be clearly understood that the contractor shall be responsible for replacing
at site, free of cost, any parts of the equipment that may prove faulty or fail by reason of
any of the causes within EIGHTEEN months after equipment has been put into operation
FORTY EIGHT months after delivery of the complete unit, whichever is later.
In case of any defect in the equipment the supplier shall rectify the same by
permissible repairs or replacement of the defective part at his own cost and after
successful rectification of the defect, the guarantees shall be applicable a fresh for a
period of 18 months from the date of such rectification.
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TECHNICAL SPECIFICATIONS:-
Name of work: - PROVIDING ADDITIONAL 11 KV FEEDER FROM
220/66/11 KV S/STN. KATHA TO KAILSH VIIHAR UNDER ESD BADDI DISTRICT
SOLAN (H.P.).
Sub-Head:- Erection of 11 KV HT line by laying 11 KV XLPE cable 3 core 300MM Sq in
cable trench
Chapter-I
ISI Marked DWC (Double Wall Corrugated) HDPE pipes:-
For laying of Power Cable applications.
TECHNICAL SPECIFICATIONS:-
TYPE (i) The HDPE pipe shall be double wall corrugated of standard make suitable
for laying 3-core 300mm square XLPE cable underground.
STANDARD:-
(ii) The HDPE pipe shall be ISI marked and complying to technical
requirement of IS-14930.
Size:- (iii) The HDPE pipe shall have OD/ED (mm) as 180/152 and have standard
length of 6 meters.
Fitting and Assembly. (vi) The scope of work shall include all fittings and accessories namely End
Caps, Bends, Tees etc required for the successful execution of laying work of the HDPE
pipe.
Non-flame propagating properties. (v) The HDPE pipe shall be of non-flame propagating type as per IS-14930
(Part-II).
Antirodancy (vi) The HDPE pipe shall have antirodancy property to prevent damage caused
due to rodants.
Inspection & Test (vii) The HDPE pipes shall be offered for inspection at manufactured work
before dispatch and test as per relevant IS shall be conducted by the authority
representative of purchaser.
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Guaranteed technical parameters of HDPE PIPE
(i) Name of manufacturer
(ii) Size of HDPE pipe (O/D)(1/0)mm.
(iii) Standard length
(iv) Colour
(iv) Method of Jointing
(v) Material
(i) whether having non-flame propagating property.
(ii) Whether having Anto-rodancy feature.
(vii) Detail of fitting accessories.
(viii) Detail of past supplies & performance.
(ix) Type test certification.
CHAPTER -II
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TECHNICAL SPECIFICATION FOR 12KV, 630 Amp, (25KA for 3 Sec)
HORIZONTAL BREAK, CENTRE POST ROTATING ISOLATORS
INDEX
Clause
No.
Title Page
No.
1.01 Scope 2
1.02 Particular of System 2
1.03 Standard 2-3
1.04 Requirement of Material 3
1.05 Horizontal Break Center Post Rotating
Isolators
3
1.06 12 KV Isolators 4
1.07 Earthing switches 4
1.08 Service Conditions 4
1.09 Technical particulars 5
1.10 Isolator insulation 6-7
1.11 Structure Foundations 8
1.12 Auxiliary Switches 9
1.13 Mechanical Strength 9
1.14 Interlocking 9
1.15 Design Feature 10-12
1.16 Fasteners 12
1.17 Metal Parts 12
1.18 Control Connection and Wiring 12
1.19 Name Plates 12
1.20 Isolator Base 12
1.21 Spare Parts 13
1.22 Special Tools 13
1.23 Cable Boxes 13
1.24 Completeness of Equipment 13
1.25 Material and Workmanship 13
1.26 Drawing and Literature 13
1.27 Tests 14-15
Annexure-I GTPs 16-19
TECHNICAL SPECIFICATION FOR 12KV ISOLATORS
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1.01 SCOPE
This specification covers the design manufacture, assembly, testing before
dispatch at manufacturer’s works, supply and delivery to station of 12KV out
door type manual operated isolators with and without earth switches along
with associated structures complete with accessories and auxiliary equipment
for installation in 33/11 KV sub station in Himachal Pradesh at Arki for 11KV
outgoing feeders. Any equipment not specifically mentioned but required for
satisfactory operation of the isolating and earthing switches in the opinion of the
tenderers must be included in the offer.
1.02 PARTICULAR OF SYSTEM
The line isolating and earth switches shall be suitable for a three phase solidly
grounded system with 50 cycles per second frequency, for the voltage class for
which these are meant.
1.03 STANDARDS
The isolating and earth switches shall comply with the requirements of the latest
editions of the following Indian standards.
(1) Alternating current Disconnectors (Isolators) and Earthing switches for
voltages above 1,000 Volts.
a. Part I General & definitions: 9921(part 1) 1981
b. Part 2 Rating: 9921 (part 2) 1982
c. Part 3 Design and construction: 9921 (part 3) 1982
d. Part 4 Type test & routine tests: 9921 (part 4) 1985
e. Part 5 information to be given: 9921 (part 5) 1985
With tender, enquiries and orders.
(2) Making and arrangement for IS 375-1963
Switchgear bus bars main connections
and auxiliary.
(3) Dimensions of indoor and outdoors 5350(PART-II) 1973
Porcelain post insulators and post
Insulator units for systems with nominal
Voltages greater then 1000 V.
(a) Out door cylindrical post insulators: 5350(Part-II) 1973
(b) Outdoor pedestal post insulators : 5350(Part-III) 1971
(4) a. 245 KV bushing porcelain parts : 3347(Part7/Sec-1)1977
b. 245 KV bushing metal parts : 3347(Part7/Sec-2) 1982
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c. 145 KV Bushing porcelain parts : 3347(Part7/Sec-1) 1977
d. 145 KV Bushing metal parts : 3347(Part7/Sec-2) 1982
(5) Porcelain post insulators for system : 2544-1973
with nominal voltage greater than 1000
Voltage (First revision).
(6) Specification for structural steel : IS 266-1975
(Standard quality) Vth revision.
(7) Recommended practice for hot dip : IS-2629
Galvanizing of iron and steel.
(8) Method for testing uniformity of : IS-2633
Coating of zinc coated articles.
(9) Specification for hot dip zinc coating : IS-4759-1979 on
Structural steel and
other Allied
products.
(10) Specification for zinc : IS-209-1979
(11) Hexagon bolts for steel structures : 6639-1972
(12) Heavy washers for steel structures : 6610-1972
(13) Galvanization of bolts and nuts : IS-5358-1969
(14) ISI handbook for structural : SP 6(I)-1964
Engineers
(15) PVC cables : IS-1554
(16) Power connectors : IS-5561
(17) Motors (If required) : IS-325
1.04 Equipment and material meeting the requirements of IEC or any other
internationally recognized standard which ensure quality equal or better than the
standard: mentioned above, shall also be acceptable. Where the equipment
conforms to any other standard, the salient points of difference between the
standard adopted and those prescribed in this specification shall be clearly
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brought out in the tender and a copy of the applicable standards shall also be
enclosed by the tenderer with the tender.
1.05 HORIZONTAL BREAK CENTRE POST ROTATING DOUBLE BREAK
ISOLATORS In this type of construction, there shall be three insulator stacks per pole. The two
on each side shall be fixed and one at the center “rotating center post”. The
Central insulator stack should swing about its vertical axis through about 900. The
isolating switches shall be double break rotating center post type for 12 KV
systems. The central post shall carry the moving tubular or flat contact arm with
the contacts, assembled at the extremities. The moving Contact shall engage the
fixed contact on the fixed contact on the fix insulator post. Mechanical
interlocking of the three poles shall ensure the simultaneous operation of three
poles. The design of moving and fixed contacts shall be sturdy so to carry the
continuous rated current without over heating and damage.
The contacts should engage perfectly so that there is no speaking while in service.
One of the contacts shall be male contact while the other is female contact. The
female contact shall be spring loaded finger contact type. The moving and fixed
contacts shall be made out of the silver faced copper in such a way that the
maximum temperature rise above 500C ambient should not be more then 65
0 C
while designing the equipment care should be taken that this temperature rise does
not cause damage to surrounding insulating material. The terminal of isolator
shall be silver plated for connection to external conductor by bolted connection.
The rotation of the central post shall be affected through a drive liver at the base
of each post connected by the operating and driven from one post by the operating
mechanism through an adjustable lever
1.06 12 KV ISOLATORS
12KV isolating switches shall be suitable for local manual operation. It shall be
possible to pad lock the manual operating handle both in open and closed position
of the switches. Isolator blades shall be so interlocked with the main breaker that
these can only be closed, if the circuit breaker is in open position. Similarly, it
should be only possible to open the isolator when the circuit breaker is in open
position. The earthing connection for the operating handle is included in the scope
of supply which shall comprise of copper leads between the operation handle and
station ground mat and interconnection between the phase bases. Six pairs of N.C.
and N.O. auxiliary switches as per detail are given here in after shall be provided
in the mechanism box for sinter locks and indications in the control room.
1.07 EARTHING SWITCHES: -
The earthing switches shall be manually operated mounted on the isolating switch
base on the line side: The earth switch shall comprise of vertical break type arm
with the contact extremity, which engages with the isolator contact on line side.
The earthing isolator and line isolator shall have a separate operating mechanism
as well as auxiliary switches to indicate in the control room, open or close
position. It should be possible to pad lock the manually operating handle of the
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switch both in open and close position. The earthing connection for correcting the
earth switch shall also be in scope of supply of supplier. This short circuit current
the earthing switches shall be of the same current carrying capacity as the main
blades.
1.08 SERVICE CONDITIONS
1. Maximum Ambient air temperature = 500C
2. Minimum Ambient air temperature = -50C
3. Altitude where these isolators have to be =below 2000 meters.
Installed
4. Relative Humidity =100%
5. Any other special conditions. =A. Excessive dust is
prevalent in Air
6. Earthquake Forces :
The equipment should be designed to withstand the
earthquake forces giving dynamic acceleration of 0.5g in
all the directions at a frequency of the order of 10 cycles
per second. Detailed calculations made for design of the
various equipment taking into account above Seismic
forces shall be furnished to the Bidder.
1.09 TECHNICAL PARICULARS/RATINGS 12KV Isolators
1. Number of poles Three
2. Class (Outdoor Air break
type)
3. Nominal system voltage 11KV
4. Highest system voltage 12KV
5. Rated frequency 50 Hz
6. Phase to phase spacing for installation 1300mm
7. Minimum clearance
(i) Phase to earth 430 mm
(ii) Phase to phase 1300 mm
8. Height of centerline of terminal 4300 mm
Pad above ground level.
9. Rated Insulation without arching hours
(i) To earth & between poles. 170 KV
(ii) Across the Isolating distances 195 KV
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10. One minute power frequency withstand test voltage (rms).
(i) Earth & between poles. 75KV
(ii) Across the Isolating distances 85 KV
11. Continuous rated current 630 Amps.
12. Short time withstand current rating from main 25 KA
Switch & earth switch for three second.
13. Rated peak withstand current 63 KA
14. Rated mechanical terminal load As per table 7 of IS: 9921
(Part-II) 1982 or as per value
to be calculated vide clause
1.16.2 whichever is higher.
15. Rated short circuit making current 25 KA
for earthing switch.
16. Neutral grounding Solidly grounded system.
17. Method of Operation Manually Operated
18. Number & type of auxiliary switches. Six pairs of NO & NC
Auxiliary switches of 10 Amps
30 VDC.
19. Control supply for semaphore lamp indications. 30VDC
SOLID CORE POST INSULATORS
20. Creep-age distance. 320 mm
21. Terminal connector bimetallic
22. terminal Connectors
(WITH NON-MAGNETIC
STAIN LESS STEEL NUTS
BOLTS WASHERS) suitable
for ACSR Panther or the size
will be intimated at the time
of drawing approval.
1.10 ISOLATOR INSULATION
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Insulation to ground, insulation between open contacts and the insulation between
phase of the completely assembled isolator shall be capable of withstanding the test
voltages as specified in clause 1.09 above. Insulation between open contacts of a pole
shall be (as per IS: 9921 part-II-1982) more than the insulation between the live parts
of a pole to ground so that if any flashover when switch is open, it shall be to the
ground.
Post insulators used in the isolators shall be SOLID CORE porcelain type suitable for
operation on system rated voltage and system earthing conditions given in the
specification. The porcelain used for manufacturer shall be sound, free from defects,
thoroughly vitrified and smoothly glazed. The glaze shall be brown in colour. The
glaze shall cover all the exposed porcelain of the insulator except those areas, which
serve as support during firing. Precaution shall be taken during design and
manufacture to avoid stress concentration due to direct engagement of porcelain with
the metal fittings, retention of water in the recesses of metal fittings. Shapes, which
do not facilitate easy cleaning by normal method, should be avoided. Cement used in
the construction of post insulator shall not cause fracture by expansion or loosening
by contraction. The cement shall not give rise to chemical reaction with metal fittings
and its thickness shall be as uniform as possible. All ferrous metal parts except those
of stainless steel if used shall be dip galvanized and the uniformity of zinc coating
shall satisfy the requirement of IS-2633-1964. The finished galvanized surface shall
be smooth.
The threads of tapped holes in the post insulator metal fitting shall be cut after giving
anticorrosion protection and shall be protected against rust by greasing. The tapped
holes shall be suitable for bolts with threads having anticorrosion protection. The
effective length of threads shall not be less than nominal diameter of bolts.
The post insulators shall be assembled in a suitable jig to ensure correct positioning of
top and bottom metal fittings relative to one another. The faces of metal fittings shall
be parallel and right angle to the axis of insulators and corresponding holes in top and
bottom metal fittings shall be in a vertical plane containing the axis of insulator.
Post insulator shall be legibly and indelibly marked to show the following:
a. Name and trade mark of manufacturer.
b. Month and year of manufacture.
c. ISI certification mark.
Marking on porcelain shall be printed before firing. These insulators shall conform to
relevant ISI/IEC. The insulators shall have requisite insulation, mechanical strength,
and thermal capability for satisfactory operation under site conditions. The creepage
distance shall not be less than 25 mm/KV.
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The insulator shall be suitable for use in moist and polluted atmosphere. The
insulators shall be capable to withstand bending and tensile strength as per relevant
ISS/IEC. Insulator shall not fail when subjected to torsion strength in tensional load
of 2.5KN and bending strength of 4KN in case of 36KV insulator. The insulator shall
be capable of withstanding the electrodynamics as well as thermal stresses.
1.10.1 SOLID CORE INDULATORS 12KV
1. Make IEC/ Modem
2. Application standard IS 2544
3. Type Solid core
4. Minimum creepage distance 320 mm
5. All ferrous parts to be hot dip galvanized
ELECTRICAL VALUES
1. Nominal system voltage 11KV
2. Highest system voltage 12 KV
3. 1 minutes P.F. withstand voltage
(Dry) 28KV (rms)
(Wet) 28KV (rms)
4. Impulse withstand voltage 70 KVP
5. Visible discharge voltage 9KV (rms)
ISOLATOR INSULATION:
Insulation to ground, insulation between open contacts and the insulation between
phase of the completely assembled isolator shall be capable of withstanding the test
voltage as specified in Clause 1.09 above. Insulation between open contacts of a pole
shall be (as per IS-9921 Part-II 1982) more than the insulation between the live parts
of a pole to ground, so that if any flashover occurs when switch is open, it shall be to
the ground.
1.10.2 INSULATOR
The insulator shall be solid core type; Porcelain PEDSTAL INSULATORS shall
not be acceptable. The makes of JSI/Modem/IEC/W.S. will be preferred.
1.10.3 MOUNTING OF ISOLATORS
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The isolators shall be mounted on the top of separated galvanized steel structure. All
couplings etc. of the main operating rods shall also be included in the scope of
supply. The height of the operating box above the ground shall be approximately
1500mm.
The operating box shall be mounted on the side of structure and it shall be at a height
of 1500mm above the ground level. Necessary length of operating rod, couplings etc.
shall be included in the scope of supply along with the earthing leads.
Where the isolators are mounted on the top of separate galvanized steel structure, the
structures shall form part of the supply scope of this specification. The structure shall
be fabricated from structural steel conforming to IS-226-1975 and shall be hot dip
galvanized as per IS-4759-1979. The purity of the zinc shall be as per IS-209-1979.
The galvanized nuts and bolts including 2.5% spares conforming to IS-6639-1972
along with galvanized washer shall be supplied along with the structure. The
galvanization of the nuts and bolts shall conform to IS-5358-1969.
The support structure shall be suitable for mounting operating mechanism etc. It shall
be designed to withstand short circuit force, wind pressure, seismic force etc. along
with the operating force vibration, shocks etc. at actual site conditions with adequate
factor of safety. The tenderer shall furnish detailed design calculation etc. for
supporting structures. These details shall also include loading data. The isolators to be
mounted on gently shall be supplied with sufficient length of operating pipe and
other, accessories to suit site requirements. In order to enable design of beam for their
mounting, necessary details of weight, dimension etc. shall be furnished to the Bidder
sufficiently in advance.
1.11 STRUCTURE FOUNDATIONS
(In case the isolator is to be erected on self-supporting G.I. structure)
The successful tenderer will be required to furnish detailed design calculations for the
structure foundations along with the dimensional drawings showing details of
reinforcement etc. The soil in which the foundations have to be laid is generally
cohesive with a safe bearing capacity of 16 Ton/m² with angle of friction as 300.
Basic design data for the structure and foundation is as below.
1. Wind pressure on Steel structures on = 195kg/m²
1.5 Times the exposed area of one face.
2. Wind pressure on conductor & ground wire = 122kg/m²
on full projected area.
3. Weight of dry earth = 1440kg/m³
4. Weight of reinforced cement concrete = 2400kg/m³
5. Concrete mixture to be used for
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(a) Pyramid or stepped part of foundation = M-15
(b) Pad = M-15
(c) Factor of safety for structure As well as foundation = 2
The passive pressure of earth shall not be considered for resisting the side thrust. In
addition, the tenderers shall specify and take into consideration the load, which shall
be transmitted to the equipment foundation under most adverse operating conditions
of the isolators.
The masonry or concrete in foundations shall be arranged and constructed by the
bidder and all requirement of foundation bolts for the structures shall be in the scope
of bidder.
1.12 AUXILIARY SWITCHES
Auxiliary switch shall be provided with each isolator and earthing switch for remote
indication and interlocking Six pairs of sturdy silver-plated NO and NC contacts shall
be provided with each auxiliary switch. Each stage of the auxiliary switch should
consist of one moving contact and two fix contacts backed by phosphors bronze leaf
springs. Connections from the auxiliary switches shall be brought to a terminal block
with the help of 2.5mm standard copper cable. The ends of this cable shall be crimped
with cable lug for connection purposes. A suitable terminal box shall be provided
beneath auxiliary switch housing for multicore control cables. For the insertion of
multicore cable in the housing cable glands of 25mm dia with a suitable rubber bush
shall be provided. The auxiliary switch shall strictly conform to the provisions of IS-
9921 or its equivalent IEC. Signaling of close position of isolator shall not take place
unless movable contact reaches their fully open position. The capacity of each contact
of these switches shall not be less than 10Amps continuous and permissible
temperature rise of the auxiliary switch contact shall be in accordance with Table-4 of
IS: 9921 Part-II. The auxiliary switches shall be capable of breaking at least 2 Amps
at 30 volts. D.C. with a time constant of not less than 20 milli seconds. Auxiliary
switches shall be positively driven in both directions. Provisions shall be kept for
adding more auxiliary switch contacts at a later stage. Separate auxiliary switches
shall be provided for isolating and earth switches. It should be possible to change
normally closed contact into a normal open contact and vice versa at site. Quick make
and break type auxiliary switches shall have been snap action built within the switch.
A cam shall actuate the auxiliary switches or similar arrangement directly mounted on
the isolator shaft without any intermediate levers linkages etc to ensure foolproof
operation.
1.13 MECHANICAL STRENGTH OF ISOLATOR
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Mechanically the isolator must be robust and able to operate successfully under
extreme climatic conditions, high winds, earthquake, low temperature and severe
pollution.
1.14 INTERLOCKING
To prevent the incorrect operation of isolating switches, earthing switches and
breakers, mechanical as well as electrical interlock shall be provided i.e. isolating
switches shall be blocked against the respective circuit breakers, switches. The
mechanical interlocking shall be provided in between isolating switch and its
earthing switch. Electrical interlock with solenoid coil in addition to mechanical
interlock shall be suitable for 30V DC supply available at site Requirement of
interlock shall be as given below:
1. Isolator should not be operated unless the associated breaker is in open
position.
2. Earthing switch shall close only when the line isolator is fully open and
locked.
3. Line isolator shall close only when the corresponding circuit breaker and
earthing switch of the corresponding lines are open.
4. The circuit breaker shall close only after all isolators associated with it
have been locked either in close or open position.
5 The bypass isolator of feeder shall close when the feeder circuit breaker
and its adjoining isolators are closed.
6 The bypass isolator of feeder shall close manually irrespective of fact
whether the feeder circuit breaker and its adjoining isolator are open and
closed.
1.15 DESIGN FEATURE
1.15.1 CONTACT SYSTEM
Contact shall be made out of hand drawn electrolytic grade copper. Arcing
contacts wherever provided shall close first and open last. The contact surface
shall be made with suitable jig to avoid deviations during up to 20-25 microns and
shall be made suitable jig to avoid deviations during production. The male and
female contact assemblies shall be of suitable design and their assemblies shall
ensure:
1. Electrodynamics with stand ability during short circuit without any risk of
repulsion of contacts.
2. Thermal withstand ability during short circuits.
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3. Constant contact pressure even when the live part of the insulator stacks
are subject to tensile stresses due to linear expansion of connected bus bar
or flexible conductors either because of temperature variation or strong
winds.
4. Self- wiping action during closing and opening
5. Self-alignment assuring closing of the switch without calling for minute
adjustments.
1.15.2 TERMINAL CONNECTORS
1. Each isolator connected with incoming and outgoing feeders shall be
provided with appropriate number of solder less clamp type bimetallic
connectors suitable for AAAC-7.4.26mm conductor for 12KV isolators.
Each isolator shall be provided with appropriate solder less clamp type
bimetallic connectors suitable for AAAC conductor as specified for 12KV
isolators. Each terminal clamp shall be suitable for both vertical and
horizontal connection of transmission line conductor or station bus bar
with non-magnetic stainless steel nuts & bolts. Each isolator shall also be
provided with appropriate number of ground terminal and clamps for
receiving ground connection. The earthing terminal shall a minimum dia
of 10mm.
2. 12KV isolator shall be able to withstand forces due to wind load on the
equipment and approach conductor and due to short circuit, all forces
considered together, for both type of isolators are connected to required to
required AAAC conductor with the adjacent span of 6 meters for 12 KV
isolators and with fault level of 25 KA isolators (12KV) for 3 seconds.
The bidder will have to submit detailed calculations providing the
satisfactory performance of the isolators in the above-mentioned
conditions.
1.15.3 MOUNTING OF CONTACTS
Fixed contacts shall be mounted on a block or channel welded 8 to 10mm thick
M.S. plate with holes for fixing on insulators. Slots shall be provided for marginal
adjustment of height of contacts. The contacts shall rest on a brass block and with
initial tension. Suitable device shall be provided to prevent dashing, fabrication,
welding etc. shall be done in suitable jig to avoid deviations during production.
1.15.4 TURN AND TWIST MECHANISM
Turn and twist mechanism shall be provided with adequate locking to avoid
opening or loosening by wind short circuit force etc. on moving blade. The
springs shall be made out of stainless steel or phosphor bronze or any other better
material to have adequate strength and resilience and shall be encased with grease
to avoid exposure to rain. The clamps and plates shall be made out of at least
10mm think. M.S. plate or flat. Fasteners with nylon lock nuts shall be used
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wherever necessary. Vulnerable parts shall be fabricated in suitable jig and
template to avoid deviations during production. Fasteners with nylon lock nuts
shall be used wherever necessary. Vulnerable parts shall be fabricated by tubular
gas cutting or milling. The entire mechanism shall be fabricated in suitable jig and
template to avoid deviations during production.
1.15.5 BEARINGS
Rotating insulator shall be mounted on a housing with bearings. The housing shall
be made of gravity die cast metal with smooth surfaces and suitably machined for
seating the bearing. Two number of bearing with adequate shaft diameter and
distance between the bearings shall be of minimum 75mm internal diameter and
of reputed make and lubricated of life. All other function locations shall be
provided with suitable bearings or stainless or brass bushes. The bearing bushes,
joints, springs etc. shall be so designed that no lubrication shall be required during
the service. Complete details of bearings bushes, housing greasing etc. shall be
furnished with the tender.
1.15.6 BALANCING OF HEIGHT:
Fixed insulators shall be provided with elevator base plate with four studs for
balancing of heights for isolator of rated Voltage of 12KV thickness of plate and
diameter of stud shall be at least 10mm and 25mm respectively. Adequate
numbers of nuts, lock nuts and washers shall be provided. Taper washer shall be
provided to match inclined surface of steel sections.
1.15.7 TANDOM PIPE:
Tandem pipes shall be used for phase coupling of double break isolators. Base
plate of insulators for connection of tandem pipe shall be made out of one piece of
at least 10mm thick M.S. plate. Bolt and shackle device shall be used to connect
tandem pipe to the base plate. These clamps shall be made out of at least 10mm
thick M.S. flat with four nos. of nuts and bolts. A grub screw shall be provided for
securing connections on tandem pipes. The tandem pipes shall be suitable to
connect the isolator in any position.
1.15.8 DOWN PIPE
At least 50mm Internal Dia and class B pipe shall be provided for operating
isolators. The pipe shall be terminated in to a suitable swivel or universal type
joint between the insulator bottom bearing and the operating mechanism to take
care of marginal angular misalignment of site. All brackets, guides etc. shall be
mounted on the base of the isolator. Arrangement of mounting any guide, bracket,
parts etc. on support structure accept the operating mechanism and the base shall
not be accepted.
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1.15.9 BASE
Each phase of isolator shall be provided with a rigid base fabricated from steel
sections. The base shall be suitable for mounting on support structures.
Fabrication, welding etc. shall be done by suitable jig, power press, and templates
to avoid deviations during production. Details and dimensions of section, jig
templates and device used for production of the base shall be furnished with
tender.
1.16 FASTNERS
Nuts, bolts and washers of 16mm and higher size shall be hot dip galvanized. The
bolts used on tapped holes of insulator cap shall be galvanized by centrifugal
process to avoid excess deposition of zinc on threads, Nuts, bolts and washer of
less than 10mm size shall be of stainless steel when used on live parts and nickel
plated brass in other parts.
1.17 METAL PARTS
All ferrous parts shall be hot dip galvanized. Bolts, nuts, pipe and washers etc.
Used on the isolators shall also be galvanized. All current carrying parts shall be
of non-ferrous metals or alloys and designed to limit sharp points, edges and
similar sharp faces. All other element shall be made of non-corrodible elements.
Isolating and earth switches may be subjected to serve atmospheric and service
conditions, therefore proper protection against corrosion shall be ensured. Design
of isolator contact shall permit easy maintenance and renewal of contacts.
1.18 CONTROL CONNECTION AND WIRING
All cable and wiring shall be suitable for outdoor operating conditions. Operating
box connections shall be insulated and fixed neatly and securely. The wiring shall
be self-extinguishing type taken from/to suitable terminal boards and run in
porcelain or non-rusting metal cleats of the limited compression type. All box
wiring shall be 2.5mm2 standard copper of 1.1KV grade.
1.19 NAME PLATES
The Isolators shall be provided with a nameplate, the nameplate shall be weather
proof and corrosion proof. It shall be mounted in such, position that it shall be
visible in the position of normal and installation. It shall carry the following
information duly punched or engraved on it.
1.20.1 ISOLATOR BASE
Name of the Manufacturer :
Year of manufacturer :
P/O No. :
Type & Designation :
Serial No. :
Rated Voltage Frequency
Rated Normal Current
Rated Short Time Current MS ES
Rated Short Time Peak Current MS ES
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1.20.2 OPERATING MECHANISM
Name of the Manufacturer
P/O No. Year
Type & Designation
Reductive gear ratio
Auxiliary contacts quantity & rating
Terminal blocks quantity & rating
Number of revolution for one close or open position
1.21 SPARE PARTS
The prices of the mandatory spare parts as listed in Annexure shall be indicated
separately in the price bid and the same shall be considered for the purpose of
tender evaluation. However the actual quantities of spare parts to be procured
shall be decided by the Bidder.
The tender may also recommend optional spare parts in addition to the mandatory
spares considered necessary for five (5) years of successful operation of the
equipment. The prices of these optional spare parts shall be as per Annexure -
However, these shall not be considered for bid evaluation. The prices of optional
spare parts shall be firm and the Bidder reserves the right to procure them any
time during the execution of contract. Spare parts catalogue depicting part
member shall be supplied.
1.22 SPECIAL TOOLS
The tenderer shall separately quote for a set of tools required for initial erection
and subsequent maintenance of the isolator and its operating mechanism. Item
wise unit prices for each tool shall be quoted in the tender. The prices of tools
shall however, not be considered for bid evaluations.
1.23 CABLE BOXES
Cable boxes including cable glands for terminating multi-core control and power
cables shall be provided wherever required. The supply shall include necessary
connecting material for mounting of cable boxes in accessible position clear of the
floor level to make the jointing work easy.
1.24 COMPLETENESS OF EQUIPMENT
All fittings, accessories or apparatus which may not have been specifically
mentioned in these specifications but are necessary for the satisfactory working of
isolator and earth switches shall be complete in all details, whether such details
are mentioned in these specification or not.
1.25 MATERIAL AND WORKMANSHIP
All material used in the construction of the equipment shall be of the best quality
available in respective kind and whole of the work should be of approved design
and make.
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1.26 DRAWINGS AND LITERATURE
In addition to any other drawing, which the tenderer may enclose to show the
merits of his equipment, the following shall be enclosed with the tender:
1. Drawing showing the outline dimensions of isolating and earth switch.
2. Sectional view and description details of items such as moving blades,
contact arms, contact spring, contact support, turn and twist mechanism,
bearing, housing of bearing, bushes, balancing of heights, phases, coupling
pipes, base plate, operating shaft, guides, swivel joint mechanism, and its
components etc.
3. Mechanical interlock between earth and isolating switches.
4. Electrical connections of controls.
5. Equipment for electrical interlocking.
6. Structure drawing for mounting of isolators along with bill of material.
7. Foundation drawings.
8. Fixing details of structures & isolators.
9. Solid core post insulator drawing with end flanges.
1.27 TESTS
Each isolator and earth switch shall comply with the following tests.
1.27.1 TYPE TESTS
1.27.1.1 The equipment/material offered in the Tender should have been
successfully type tested in line with standard and Technical Specification from
Independent test house. The bidder shall be required to submit three copies of the
type test report along with the offer. Tenders not accompanied with all type test
reports shall not be considered.
Detail of Type Test
1) Dielectric tests. (Power frequency & lightening impulse).
2) Temperature rise test.
3) Short time with stand current and peak with stand current test on main
switch.
4) Type tests on solid core insulator (as per ISI-2544).
5) Type tests on Terminal connectors.
6) Operating and mechanical endurance tests. On isolators, operating
mech. and auxiliary switches
1.27.1.2 If there is any change in the components or designs in the equipment since after
passing of the Type-test, the bidder shall bring out in his offer all such changes
made in the components, materials, designs etc. In such case the bidder shall
carryout the type test at his cost and in the present of Bidder’s representative.
1.27.1.3 Even if the equipment/material has been type tested earlier, the Bidder reserves
the right to demand repetition on one or more test included in the list of type
tests in presence of Bidder’s representative. For this purpose the bidder shall
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quote unit rates for carrying out each type test included in the list of type tests as
per relevant Standard and Tender Specification.
1.27.1.4 During the type test the disconnector shall be mounted on its own support
structure or equipment support structure if any and mounting arrangements
made for type test shall be furnished for Bidder’s approval before conducting
the type tests.
1.27.1.5 The type tests shall be connected on the Disconnectors along with approved
insulators and terminal connectors.
1.27.1.6 Mechanical endurance test shall be conducted on the main switch as well as
earth switch on one Disconnectors of each type.
1.27.2 ACCEPTANCE AND ROUTINE TAESTS
Routine tests as per IS 9921 (Part-4) IEC 129-1961 shall be carried out on each
isolator in the presence of Bidder representative expenses for the routine test
conductance shall be borne by the manufacturer. All test reports should be
submitted and got approved from the Bidder before the dispatch of equipment.
The tenderer shall however submit the details of routine tests facilities, which
are available in their works.
1.27.2.2 Mechanical operation tests (routine tests) shall be conducted on the complete
isolator (main switch and earth switch) at supplier’s works and a certified test
report be furnished to the Bidder.
1.27.2.3 The test report of power frequency voltage withstand test conducted on the
insulators shall be furnished for Bidder’s acceptance in lieu of conducting
power frequency test on main circuit (routine test).
1.27.3 SPECIAL TESTS
Special tests as listed below shall be carried out in the presence of Bidder’s
representative. Without any price implication.
1. Tests on insulators IS 2544/IEC168
2. Tests on terminal connector IS:5561 or Equipment
standard
3. Tests on galvanized component IS: 2623
4. Operation tests on operating Mechanism and interlock.
5. Endurance test on auxiliary Switches.
6. Tests on silver coating.
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1.27.4 Test certificates and documents of the following items shall be furnished at the
time of routine tests.
a. Chemical analysis of copper along with a copy of central excise
certificate/gate pass indicating genuine source of procurement of
electrolytic grade copper.
b. Bearings.
c. Fasteners.
d. Universal/swivel joint coupling
e. Insulators.
f. Gears.
g. Auxiliary Switches.
h. Interlocking Devices.
i. Terminal Block.
The Purchaser may at his discretion request additional test certificate for other
items as reasonably require to substantiating quality of the same.
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ANNEXURE-I
SCHEDULE OF GUARANTEED AND TECHNICAL PARTICULARS
(TO BE FILLED IN BY THE TENDERER)
SR.NO. DISCRIPTION 12KV ISOLATORS
1. Make of origin
2. Type
3. Mode of operation
4. Indoor or outdoor
5. Rated frequency
6. No. of poles
7. Rated Voltage.
8. Maximum permissible Voltage.
9. Power Frequency test Voltage (withstand)
(a) Against ground
1. Dry
2. Wet
(b) Across the open ends.
1. Dry
2. Wet
(c) Between phases
1. Dry
2. Wet
10. Impulses withstand test voltage without arcing horns for 1.2/50 micro sec.
impulse waves.
(a) Against ground.
(b) Across the open ends of the same phase.
(c) Between phase
11. No. Of break per phase
12. (i) Continuous current rating
(ii) Rated current at:
a. Reference ambient temperature.
b. Ambient temperature of 450C
13. Rated short time withstand current for 3sec.
14. Rated peak short circuit current
(a) Rated peak short circuit current of main disconnect or.
(b) Rated peak short circuit current of earthing blade.
15. Fault current, which can be made by the earthing switch.
16. Transformer magnetizing current that can be broken.
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17. Line magnetizing current that can be broken.
18. Type of terminal for receiving line/bus conductor.
19. Phase to phase distance
20. Auxiliary switches.
a. No. of normally open and normally.
b. Rated voltage.
c. Rated current.
d. Test voltage.
e. Terminal block type, voltage and current rating.
f. Details of electrical inter locking device.
g. Wattage of interlocking solenoid coil.
21. Design and construction
I No. of insulators per pole.
ii No. of breaks per pole.
iii Type of closing/opening mechanism
(turn and twist or straight etc.)
iv Female contacts.
22. Particulars of main contacts i.e. fixed contacts (main switch) and earthing switch
and moving contacts.
i. Type.
ii Material
iii Surface treatment.
iv Thickness of surface coating.
v. Contact area.
vi. Contact pressure.
vii Diameter of copper pipe moving blade(inner dia outer dia)
23. Arcing contacts:
i. Type
ii Material
iii Whether contacts silver plated
iv Thickness of plating
v. Current carrying capacity.
24. Current density at the minimum cross section in (A/Sq. mm)
i. Moving blade (Amps.Sq. mm)
ii. Terminal pad (Amps.Sq. mm)
iii. Female cont act (Amps.Sq. mm)
iv. Terminal connector (Amps..Sq. mm)
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25. Rated mechanical terminal load.
i. Load along the terminal connector side.
ii. Load across the terminal connector side
26. Torque required to operate the switch (kg.m)
27. Contact support.
i. Material and size of channel/block.
iii. Material and size of plate.
28. De-rating factor for specified site conditions.
29. Minimum clearance in air:
i. Between poles (mm).
ii. Between live parts and earth (mm).
iii. Between live parts when switch is open
a. On the semaphore
b. Between adjacent poles (mm)
30. Insulators:
31. Make
a. Type
b. No. of units per isolator(mm)
c. Height of each insulator stack (mm)
d. No. of holes size and pitch circle diameter(mm)
e. Tensile strength.(kg)
f. Compressive strength (kg)
g. Tensional strength(kg-cm)
h. Cantilever strength upright (kg rms)
i. Rated voltage (KV rms)
j. Power frequency dry flash over voltage. (KV rms)
k. Power frequency wet flash over voltage. (KV rms)
l. Impulse withstand voltage (KV peak).
m. Impulse withstand voltage (KV peak)
n. Power frequency puncture voltage (KV rms).
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o. Visual discharges voltage level (KV rms)
p. Creepage distance total protected (mm).
q. Dry arcing distance.(mm)
32. Clearance (Minimum)
a. Between live parts and ground.
c. Between phase.
33. No. of times the switch can be operated without any need for inspection.
34. No. of operations which the switch can withstand distortion on contacts.
35. Weight of one three pole-isolating switch without earthing blade.
36. Weight of one three pole-isolating switch with earthing blade.
37. Base
a. Size of steel section used.
b. Overall size.-*
d. Total weight.
38. Terminal connectors.
a. Clamp body alloy composition plating if any. Area at minimum cross
section.
b. Bolts and nuts size alloy composition Tensile strength.
c. Type of washers used.
d. Material of braids.
e. Temperature rise when carrying rated current at 50 C ambient
f. Weight of each type of clamp (kg)
39. Tandems pipe.
a. Size class and No. of Pipes.
b. Size of shackle and screw.
c. No. of clamps and the material and size.
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40. Down pipe size and class
41. Nuts and bolts.
a. Size material and grade in live parts.
b. Size, material and grade in other parts.
42. Turn and twist mechanism.
a. Material and size clamps.
b. Material and size of springs.
c. Whether springs are encased.
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Chapter-III
Excavation in Trenches
(i) The cable trench shall be of 1 mtr. X 0.6 mtr. Size. The bidder should quote his
rates for all kinds of soil including all leads and lifts.
(ii) The valuables if any extracted during excavation shall be returned to the
department by the contractor.
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