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TECHNICAL SPECIFICATION FOR FIELD WORKS (11kV Lines)

1. SURVEY OF EXISTING AND NEW LINES AND S/S :

Survey shall have to be carried out by the Contractor of existing lines & S/S and new lines

and S/S for new construction. The drawings shall be prepared showing the existing lines

and S/S for new lines & S/S to be constructed.

2. SPAN:

Span length for 11 KV lines & LT lines shall be maintained 70 mtrs. and 50 mtr.,

respectively for new lines. In case of road crossing and canal crossing the span length

shall be maintained as per field requirements.

3. CLEARANCE FROM GROUND BUILDING ETC:

Clearance from ground building shall be maintained in conformity with I.E. rules 1956

as amended upto. The bidder shall select and heightening the pole such that all electrical

clearance are maintained.

Guarding shall be used in all road / cannel crossing and at points as per statutory

requirements as per REC specification A-1.

Pole accessories like danger plates and phase plates respectively shall provided.

4. EARTHING OF POLES:

Each HT pole shall be carried with coil type earthing as per REC construction standard J-1.

5. SUPPORTS :

5.1 Poles are to be excavated to size of 0.6x0.6 mtr. upto a plantation depth 1/6 of the height

of the support for HT & LT supports.

5.2 Padding of pole : The padding of the pole (RS Joist / PSC pole) shall be done with 1:4:8

PCC of thickness 150mm using black hard granite metal of size 40mm.

6. PROVIDING OF GUYS / STRUCT POLES TO SUPPORTS:

The arrangements of guys shall be made wherever necessary struct poles / flying guys

wherever required shall be as per REC specification standard G-2 X G-3.

The anchor type guy sets are to be used an angle location, double poles, dead location,

cut-point.

G.I. stay wires of size 7/3.15 mm (10 SWG) with GI turn buckle rod of 16 mm dia & 16 mm

dia GI stay rods shall be used for 11kv.

For double pole structure (DP), four stays along the line, two in each direction and two

stays along the bisection of the angle of deviation ( or more ) as required depending on

the angle of deviation are to be provided. Hot dip galvanized stay sets are to be used.

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The anchor plate shall be fixed to 200mm X 200mm MS plate of 6mm thickness. M.S. rod

with a bolt arrangement at one end and other end is given shape of 40mm dia circle to

bind one end of the stay wire. The anchor plate shall be buried in concrete.

The turn buckle shall be mounted at the pole end of the stay and guy wire so fixed that the

turn buckle is half way in the working position, thus giving the maximum movement for

tightening or loosening.

If the guy wire proves to be hazardous, it should be protected with suitable asbestos pipe

filled with concrete of about 2 m length above the ground level, painted with white and

black strips so that, it may be visible at night.

Stay shall be erected with concrete of ratio 1:3:6 foundation of size 900x900x750 mm using

hard granite crusher broken chips of 12 mm size.

Struct shall be erected with concrete of ratio 1:3:6 foundation of size 900x900x900 mm

using hard granite crusher broken chips of 12 mm size.

7. INSTALLATION OF LINES MATERIALS:

7.1 Where change of insulators required, prior to fixing, all insulators shall be cleaned in a

manner that will not spoil, injure or scratch surface of the insulator, but in no case shall

any oil be used for that purpose.

Pin insulators shall be used on all poles in straight line and disc insulators on angle and

dead end poles. Damaged insulators and fittings, if any, shall not be used. The insulator

and its pin should be mechanically strong enough to withstand the resultant force due to

combined effect of wind pressure and weight of the conductor in the span.

7.2 Strain insulators shall be used at terminal locations or dead end locations and where the

angle of deviation of line is more than 100, if not existing in to line. Strain insulators shall

be used at major crossing.

7.3 The pins for insulators shall be fixed in the holes provided in the cross-arms and the pole

top brackets. The insulators shall be mounted in their places over the pins and tightened.

In the case of strain or angle supports, where strain fittings are provided for this purpose,

one strap of the strain fittings is placed over the cross-arm before placing the bolt in the

hole of cross-arms. The nut of the straps shall be so tightened that the strap can move

freely in horizontal direction.

7.4 Handling of Conductor.

7.5 Running out of the Conductors: The contractor shall be entirely responsible for any

damage to the pole or conductors during stringing. Care shall be taken that the

conductors do not touch and rub against the ground or objects, which could scratch or

damage the strands.

7.6 The sequence of running out shall be from the top to down i.e. the top conductor shall be

run out first, followed in succession by the side conductors. Unbalanced loads on poles

shall be avoided as far as possible. When lines being erected run parallel to existing

energized power lines, the Contractor shall take adequate safety precautions to protect

personnel from the potentially dangerous condition.

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7.7 Monitoring Of Conductors During Stringing:

The conductor shall be continuously observed for loose or broken stands or any other

damage during the running out operations. Repair to conductors, if necessary, shall be

carried out with repair sleeves. Repairing of the conductor surface shall be carried out

only in case of minor damage, scuff marks etc. The final conductor surface are be clean,

smooth and free from projections, sharp points, cuts, abrasions, etc. the Contractor shall

be entirely responsible for any damage to the poles during stringing.

7.8 Painting Of Materials:

All the metal parts except GI parts are to be painted with one coat of Red oxide and one

coat of Aluminum paints.

8. STRINGING OF CONDUCTOR :

8.1 The works include spreading of conductors without any damage and stringing with proper

tension without any kinks / damage including binding of conductor at pin points,

jumpering at cut-points etc. the ground & line clearances at road crossings along roads

other crossings shall be as per the relevant I.E. rules.

8.2 While transporting conductors drums to site, precautions are to be taken so that the

conductor does not get damaged. The drum shall be mounted on cable drum support.

The direction of rotation of the drum shall be according to the mark in the drum so that

the conductor could be drawn. While drawing the conductor, it shall not rub causing

damage. The conductor shall be passed over poles on wooden or aluminum snatch block

(pulley) mounted on the poles for this purpose.

8.3 The conductor shall be pulled through come-along clamps to stringing the conductor

between the tension locations.

8.4 Conductor splices shall not crack or otherwise be susceptible to damage in the stringing

operation. The Contractor shall use only such equipment / methods during conductor

stringing which ensures complete compliance in this regard. All the joints including mid

span joints on the conductor shall be of the compression type. In accordance with the

recommendations of the manufacturer. Each part of the joint shall be cleaned by wire

brush till it is free of rust or dirt, etc. and be properly greased with anti-corrosive

compound, before the final compression is carried out with the compressors. After

completing the jointing, tensioning operation shall be commenced.

8.5 All the joints or splices shall be made at least 15 meters away from the pole. No joints or

splices shall be made in spans crossing over main roads, railways and small river spans.

Not more than one joint per sub-conductor per span shall be allowed. The compression

type fittings shall be of the self-centering type. After compressing the joint, the aluminum

sleeve shall have all corners rounded; burrs and sharp edges removed and smoothened.

9. AB CONDUCTOR STRINGING :

AB conductor on LT PSC pole shall be drawn with dead end clamp and suspension clamp

with I hooks. The service connection shall be given to consumer with help of piercing

connector etc.

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10. EARTHING :

Pipe earthing shall be done with excavation of earth pit in all kinds of soil of size 900x900x

depth 3500 mm and using 40 mm dia 3 mtr. long GI pipe and filling with alternate layer

of 300 mm charcoal salt upto 3000 mm from bottom of the pit and balance shall be filled

with barrowed soil and with a brick masonry chamber size 600x600x600 mm, 300 mm

below from ground level and 300 mm above ground level including all connection with GI

wire of specified size.

Coil earthing shall be done with excavation of earth pit at distance 1.2 mtr. from the pole in

all kinds of soil and size 600x600 and depth 1500 mm installing coil earth filling with

alternate lair of 300 mm charcol & salt upto 1200 mm depth from bottom of the pit and

the balance depth shall be filled up with available excavated earth in the pit and

connecting coil to the earth nut of the support.

11. GUARDING :

Guarding shall be done at road crossing / cannel crossing with fixing of guarding cross

arm, laying and stringing of 4 nos. of guarding bearer wire in parallel with No. 6 / No. 8

SWG GI wire including fixing of lacing for protective guarding with a spacing of 2 mtr. as

per REC connection standard specification A-1.