ACFR INSTALLTION GUIDELINE

1.3.

Cross sectional area of aluminum is increased by thetrapezoidal wire which increases the transmission capacity
and/or lowers ohmic losses. EC grade hard drawn
aluminum wire or thermal resistance wire of Al-Zr alloy or
EC grade annealed aluminum wire can be used for the
conductive layers. Caution should be used to avoid
damaging softer annealed aluminum by dragging or
scratching the surface.

1.4.

ACFR’s maximum operation temperature is 180℃ and
200℃ for emergency.

Rev.4 Aug. 2022

1.

Aluminum Conductor Fiber Reinforced(Annealed Aluminum Wire or TAL/ Hard Drawn Wire)

CFCC: Stranded Carbon Fiber Composite Core

1.1. ACFR conductor uses a high-strength stranded composite core
(Carbon Fiber Composite Cable: CFCC) which consists ofcarbon fibers and thermoset resin matrix. CFCC has 1/5 theweight and 1/12 the thermal expansion coefficient compared
to conventional stranded steel wire. The reduced weight of thecomposite core and lower coefficient of thermal expansion
allows the ACFR to carry up to twice the current of
conventional conductors while lowering transmission losses.

Initial Sag
Final Short-Term Creep or Long-Term CreepMax Ice/ Wind Load
Final: 100°for ACSR/150-200°for ACFR

1.5.

1.2. Stranded construction of the CFCC provides flexibility,
structural redundancy and practical handling. Flexibility of thecore translates into lesser chance of breaking the core which
prevents re-work and saves time during installation process.
Conventional ACSR installation technique can be used.
Upgradation of tools required for installation of ACFR is
minimum.

To avoid damaging the conductor, tension stringing method
is recommended. Extra care to control bend and twist
shall be taken as well as ensuring proper splicing. While
steel strands are hard and can resist crushing loads, the
CFCC core can sustain damage if the conductor is crushed.
ACFR conductor is relatively flexible and can tolerate someabuse and round bending to some extent; however, careshall be taken to avoid local bending, twisting and crushing.
Driving a vehicle across a cable, unsupported conductor end
hanging down from conductor grip, sharp bending byhoisting or laying conductor over obstacle are examples ofabuse that a steel core conductor might survive but might
damage the composite core. It is okay to drape slack
conductor across small roller but it would not be
acceptable if the bend were sharp and local and the
conductor were under tension.

✓Round bend

X Sharp local bend

1.6. Avoid excessive bending: A steel strand will kink if it is bent,
but it can be straightened with only moderate loss of strength.
Each CFCC core is tested at the factory to ensure it can toleratereasonable bending stresses during installation. Unlike steel
strands, CFCC core strands do not yield or kink when bent pasta safe diameter. Local bending should be avoided at all times.
It must be assured that safe margin is kept to the breaking point
during all handling and installation. Care shall be taken tomonitor, detect and report any event where thebending/twisting limit could have been exceeded. Exceeding
the limits will result in distortion of aluminum layers.
Damaged conductor should be repaired and/or replaced.

1

2

TRANSPORTATION AND BASIC HANDLING

2.1.

Loading and unloading of ACFR drum should be performed
in a manner that the conductor drum remains in vertical
position and the reel flanges are not damaged. The drums
should never be thrown from the truck during unloading,nor should they be moved by uncontrolled rolling. The
drum should not be transported and/or stored on its side
under any circumstances. The conductor ends should be
fixed to prevent the conductor from slackening. All of the
staves and/or safeguards should be maintained until thedrums are set-up for immediate installation.

2.4.

A bending limit should be maintained at all times.
Assure that conductor does not bend more than allowable
bend diameter of 40 x conductor diameter at all times.

Spreader bar✓
40 x Dc

2.2.

2.3.

Conductor should be stored away from direct heat andrain as this would cause oxidation. Conductor surface
would turn dark or black if oxidized. (however, is not a
defect). The drums should be stored off the ground and the
conductor ends should be sealed to prevent water
penetration. It is always recommended to store drums inside
warehouse.

2.5.

Conductor Oxidation / Staining. Oxidation on the
conductor can be caused by exposure of conductor toatmosphere which results from a chemical reaction between
oxygen and aluminum. While it is normal for oxidation toform, the conductor must be brushed and cleaned properlyin these areas prior to installing the hardware to ensure
adequate metal-to-metal contact. (Also, a black “water stain”
can appear on the conductor if the moisture accumulated on
the conductor contains chemicals from the surrounding
atmosphere and they have no adverse effect on theperformance or service life of the conductor.)

2

Rewinding excess ACFR conductor on its drum can bedone manually or hydraulically with light back tension.
Conductor should not bend, twist, rub or scrape on theflanges. Assure that each wrap of the conductor does notcross over during rewinding as the core might be damaged
when it is paid out with back tension.

3.

PULL / TENSION SITE

Lower the height ofTensioner capstan-first sheave should be lined up straightfirst sheave (or use
bigger sized sheave)
if 1:3 is not possiblea < 30° is desirable

3.1.
A)
B)
C)
D)
E)
F)

G)
3.2.

3.3.

The pull/tension site should be selected considering thefollowing:
Distance and alignment from the 1st/last tower
Availability of area to be used for setting up drums,
puller/tensioner
Accessibility for transportation by trucks
Crossings and obstacles (rollers, scaffoldings, cradle
method, safety net, clearance from energized lines)
Number of sheaves (< 20 sheaves)
Pulling tension and required clearance (pulling tension≦10% RTS of the conductor(s) and/or 50％ of sagging
tensionPulling length (< 20 spans or 3 drums)

3.4.

Running grounds should be installed along two points in the
pull: one between the reel stand or tensioner and the firststructure, and the other between the puller and the laststructure. Running grounds should be bonded to theestablished ground and free-wheeling not to cause surface
abrasion or bird caging.

3.5.

DO NOT USE smaller than 40 x Dc Bullwheel
recommended diameter which may cause a build-up of
torsional stress into the conductor. The need for larger
diameter is crucial.

The puller and tensioner shall be positioned at a distance ofmin. 3 times the height of the connection point of the phasebeing strung which corresponds to an upwards conductor
angle of about 20 degrees. This practice will limit the verticalload on the structure and also the conductor pressure on thefirst sheave by larger pulling slope. In case that this 3:1 rule is
not achievable, larger or tandem sheave configuration at thefirst structure should be used according to the entering angle
or the height of the first structure running block may belowered.

DBW > 40 x Dc

3.6.

Tensioner should be of rubber faced double bull wheel
type (or Tilted Multi Groove Tensioner) with sufficientnumber of grooves to keep the outer layer from slipping
over the underlying layer 4 wraps). Groove surface shall besmooth and free from rough edges. (Single V-groove typebull wheel or Combination Bull wheel Tensioner/pay-off
Trailer shall never be used).

3.7.

The conductor end pulls from top of the drum and aligned
straight with the groove of the tensioner capstan. ACFR
conductors built right-hand lay (“Z”) shall be fed throughfront tensioner wheel on left-most groove and exit from the
top right-most grooves of the back-side-wheel, facing in the
direction of the pull within < 5°deviation on the right halfside.

The tensioner as well as the puller and the sheave at first/laststructure shall be aligned with the planned direction of pull.
Deviation in the direction of pull (α) shall not exceed 30°.

✓No Bending

3

3.8.

Tension Site Set-up
A Slight droop indicated good right back-tension (back-tension to be kept minimum)

Anchor > 3 x back-tension

Tensioner feed sheave to assist smooth payout
AnchorRunning> 3 x back-tension
ground (avoid surface abrasion)

Fair lead roller guides (avoid sharp bending)Hydraulic / Mechanical braking
system to prevent over spooling(Synchronized with the tensioner)
Anchor > 3 x back-tension

Double Bull Wheel Dia. > 40 x Dc

A)

Bullwheel Diameter must be bigger than 40 x
conductor Diameter.

B)

Radius of the grooves (Rg) should be sized correctly.

and the tensioner to allow the strand looseness to distributealong the intervening length of conductor evenly andsimultaneously maintaining enough back tension on the drum
to stretch the core and inner strands to sufficiently tighten theouter strands.

PULL TO TOWER

PLAN
VIEW

> + 4 WRAPSFROM CONDUCTOR REEL

Don’t let the conductor rub
on the side of the groovesC)

Tensioner feed sheave must be used to correct deviationand facilitate smooth entering of the conductor into thetensioner in a manner that conductor is not being twisted
or bent. Problem of bird caging can be remedied byallowing enough distance between the conductor drum

4

D)

The puller and the tensioner must be rated for pulling
capacity and equipped with dynamometer (tension
indicator), limiting devices. (The annexure D,F,H & I of
IEEE524 may be referred for calculating the capacity)
Positive braking system is required to maintain a constanttension to operate smoothly without causing any sudden
jerking or bouncing of the conductor at all pulling speed
and when the pulling is stopped. Recommended speed of
payoff is 20-40m/min. Increase and decrease of pulling
speed should be gradual. Swinging of the conductor
caused by inconsistent pulling speed or unsynchronized
operation should be avoided.

E)

Assure that the conductor is not jumping or bouncing
during payout. Synchronized breaking of the drum withthe tensioner is desirable. Excessive braking can cause the
top layer of conductor to “crush down” into theunderlaying wraps and damage or distort the outer strand.

3.10. Slack and Layout Method

F)

Slack and Layout method is applicable when maintenance ofconductor surface condition is not critical (or matting to protect the
conductor surface is provided) and where the terrain is easily
accessible to a pulling vehicle. This method should not be used inurban locations where hazards exist from crossing traffic orenergized circuits, nor is it practical in hilly terrain inaccessible topulling vehicles. This method is not desirable for:Drum/ Drumstand: The braking of the drum shall be kept
as minimum level necessary to allow the tensioner todraw new conductor from the drum smoothly and evenly
and also to prevent over-rotating (backlash or freespooling) when the pulling stops. The braking force
should not exceed 4.5kN. Pay-off brake tension shall be
continuously monitored throughout the pull and loweredas the drum empties.

➢
➢
➢
➢

Annealed aluminum conductor
Urban locations
Crossing traffic or energized circuits
Hilly terrain

3.11. Manual Stringing
A slight Droop indicatesgood back tension

A)

Workers manually pulling
conductor, avoid sharp bend

Drum flange 10-15cm
off the ground

3.9.

AVOID damaging the soft aluminum layers by dragging
the conductor on the ground or over obstacles. Conductor
being paid out should be laid on matting on the ground toprevent scratching and damaging on the soft surface of
annealed aluminum wires. It shall be assured that the ACFR
conductor is always kept out of the dirt.

Matting/Spacer to keep the
conductor from scratching

Semi-Tension Method (for smaller dia. conductor)
B)

Semi-tension method is similar to tension stringing method except
in this method the conductor is pulled directly off the pay-out drum.
Very low clearance is maintained by applying minimum breaking
force to the payoff drum. Breaking force shall be kept minimum
level necessary as not only to prevent damaging the remaining
conductor on the drum but also to prevent collapsing the drum
itself. Drum stand must be securely anchored with > 3 x pulling
tension. Breaking capacity of the drum must be checked to be
sufficient for the planned pulling tension for maintaining required
clearance; or Tension stringing method (with breaking bytensioner) or cradle method should be considered in case thatpulling tension exceeds breaking capacity of the drum. Any bellies
which may cause excessive bend must be avoided and min.
Bending radius must be respected at all times.

5

The conductor should not be dropped or pulled overobstacles or edges such as rocks, walls, fences etc. All
obstacles such as Rocks, Walls, Fences, Trees, Rivers, Roofs,
Scaffoldings along the way shall be treated in a manner thatwill not cause excessive bend or dragging. It shall be assured
that the conductor will contact only surfaces that areminimum sheave working diameter or greater. Rotation of thedrum should be controlled with minimum breaking force toprevent over run, backlash or loop to avoid damaging theremaining conductor on the reel.

C)

D)

4.

Avoid any bellies which may cause excessive bend during
manual stringing. Particular care shall be taken when lifting
up the conductor not to allow sharp bends of the conductor.
Deformation of aluminum strand should be evaluated for the
possibility of damage to the core.

INSTALLATION OF RUNNING SHEAVES

4.1.

A minimum bottom groove diameter (Ds) of 20 x conductor
diameter (Dc) is generally recommended for typical pulls
with level spans and partial turns (less than 60°). Ds must be> 60 x cfcc core diameter. DO NOT USE smaller thanrecommended diameter sheaves which may cause buildup of torsional stress into the conductor and/or
distortion of aluminum layers.

4.2.

All sheaves should be lined with a resilient liner such as
neoprene or polyurethane and constructed of lightweight,
high-strength materials. Plastic lining of urethane or
neoprene with rigid frame are recommended. It is advisable
to check that their inner surface is free of defects that could
potentially scratch the conductor’s aluminum strands. Barealuminum sheaves are not acceptable for annealed
aluminum conductor as it may damage the surface of the
conductor. All sheaves must be checked for load rating andin good working condition without damage/worn andproperly lubricated prior to use.

4.3.

Radius of Groove: Use well-fitting groove to ensure
efficiency of the stringing operation and to avoid unevenpressure applied to conductor as it passes through thesheave and build-up of torsional stress on the conductor.
IEEE524 criteria should be applied for selection of sheaves.

Avoid sharp bend when laying the conductor over structure. It
is okay to drape slack the conductor across small roller but it would
not be acceptable if the bend were local and the conductor were
under tension. Conductor should not be pulled across obstacles.

✓(and > 60 x cfcc core dia.)

✓

4.4.

When pulling the conductor around angles greater than 60°,
or when there is severe uplift or down pull forces, Tandem
or oversized sheaves should be used to minimize breakover
angles/keeping allowable bending radius.

Up to 60°

Roller should be used when pulling the conductor over obstacles

Tandem sheave hanger

6Roller Array

20 x Dc dia Sheave

4.5.

It is advisable to use oversized sheaves when pullingthrough hilly terrain.

5.4.

Conductor will tend to loosen or tighten its strand whentravelingsheaves,turning
50-55
degreeConductor overwill tend
to loosen
or tighten
its strand
whepersheave. If the conductor runs off the center, it will rollon sides and being twisted which would cause
loosening/squeezing of the strand and/or damaging thecore of the conductor.

5.5.

When multiple reels are pulled to extend sections, splices
are normally installed only after the conductor has beenpulled into position. ACFR conductor splices must never beallowed to run through sheaves, (unless specialized splices
and procedures are certified to facilitate safe, reliableinstallation.) Up to three drums joined by proper wire meshgrip may be pulled back-to-back if the site conditions don’tallow proper access. As a guideline, pulls should not be
more than 20 spans.

5.6.

Torsional stress that is built up in the conductor willtend to be concentrated at most the vulnerable portionof the conductor when stringing tension is not kept
constant.

5.7.

Maintaining constant tension is crucial to evenly distributetorsional stress over the conductor. Excessive built-up of
torsional stress into conductor can result in birdcaging,
Squeezing, and ultimately damaging the core. Excessive
accumulation of torsional stress into the conductor will
result in the opening of strand (birdcaging - loosening) or
popping out of outer aluminum strand (snaking - squeezing).
Installer must spot distorted portion of aluminum layers andevaluate the damage

Bending angle > 60°

4.6.

5.
5.1.

Sheaves at angles should be RIGGED UP to match theplan of the conductor path to allow the conductor to rollalong in the center/ bottom of the groove to minimize
torsional stress.

PULLING CONDUCTOR(S)
Pulling wire (RTS>2.5 pulling tension) should be lighter
than the conductor to avoid unnecessary increase of thepulling tension.

5.2.

Torsion releasing swivel must be used in connection withthe pulling wire and new conductor. it is recommended to
install counterweights at head of the conductor

5.3.

In case that old conductor is used as a pulling wire, it must
be assured that the old conductor is free from damage.
swivel is required between the old conductor and new
conductor (and desirable for between grips if multiple reels
are tied together for longer pulls) as to avoid transferring
the torsional stress from the old conductor. The swivel mustrotate freely during the pulling process. The swivel shouldbe periodically tested under load.

7

5.8.

It should be noted that twisting of conductor should notexceed the below limit which is based on the Forcetwisting test result of ACFR 200mm2 till core failure.
(Length: 1m, Dc: φ18.31mm, 2 layers + φ6.8mm cfcc core)Turning (outermost layer)

5.11. When pulling through long sections and/or with higher
pulling tension, installing split-type core retainer with lockbands, which keeps the CFCC core from slipping inside(soft) aluminum layer, is recommended so the core can beaccessible for splicing.

Core Failure

Squeezing：

250°/1m

Loosening：

360°/1m

Example of conductor core failure as a result of excessive built-up of
torsional stress into short length of the conductor caused by:➢➢➢① Exceeding the back-to-back pulling limit (pulling section exceeds

20 spans) .
② Failure to use torsion releasing technique (swivel was not used
between drums and the midspan joint splice was installed at tension
site for connecting conductor drums.
③ Poorly maintained non-rotating running sheaves and the conductor

not running center bottom of the groove caused more turning of the
conductor.
➢⑤ Inconsistent pulling tension causing concentration of torsional

stress into short length of conductor.
➢⑥ Failure to monitor conductor condition when passing throughsheeves and ①-⑤ were not corrected during the pull.

5.9.

ACFR conductor may be pulled back-to-back up to 20
spans. Each conductor ends must be joined by two wire
mesh socks with core retainer. Jointing swivel isrecommended be used between each drum for assuringsafety. Midspan joint splices must be installed after the
conductor is in place or pulled through the last relevantsheave. Midspan joint splices must never be pulled throughsheaves unless specialized sheave arrangement andprocedures are certified to facilitate reliable installation.

CFCC core can slip inside aluminum layer by tension stringing

5.12. The weight of Running Board shall be sufficient to prevent
conductor rotation as recommended below (for single
conductor). In case of pulling longer than 4km, these values
may be increased by 5kg. Running board must be used inpairs (3 meters apart) so that one of them is always
operative when the other one is running through sheave.

5.10. Double check equipment condition and load ratings ofswivels and wire mesh grip since back-to-back pulling
requires higher pulling tension (must never exceed 70 % ofsagging tension). A Correctly Sized woven wire mesh grip
to fit over the conductor with adequate length should be
used. (A+L 1.70m is recommended). Mismatch indimension may result in conductor slip or damage to the
conductor. Grip must be double-banded on the ends toprevent slipping. The portion of the conductor that arecovered with wire mesh shall be cut off after removal ofwire mesh.

5.13. In general, max. pulling tension will be about 50 (to70%) of sag tensions and < 20%RTS. Caution should be
used since over- tensioning may cause build-up of
torsional stress into the conductor. Sag tension shallnever be exceeded during stringing or sag behavior will
be affected.
5.14. Pulling Tension will vary depending on environmental
condition of intended route and the stringing efficiency.
General pulling tension (single) for conventional sizes are:
➢
➢
➢

8

ACFR410mm2:
ACFR610mm2:
ACFR810mm2:

1,600-2,600kgf
1,800-3,000kgf
2,300-3,200kg

5.15. Back-tension is approximately 75% of pulling tension.
Pulling through angles and elevation changes will increase
the pulling force and tighter sag values with clearance
restriction will also increase the pulling force. Pulling
tension on conductor will increase 2% when travelingthrough one sheave and large elevation changes also
increase the pulling tension by the net weight of the
conductor(s) in the vertical change. In case that pulling
tension exceeds more than usual, pulling section may be
broken down into separate pull. Increase/decrease ofpulling speed should be gradual. Swinging of conductor
should be avoided.

6.1.

Note that for smaller/medium conductor tandem gripping
is recommended, below ~24 mm is double grip. Grip jaws
may be round or oval but not V-shaped. Do not use any
grip with an off-set in the jaw area as it could damage the
core.

6.4.

In case of gripping for higher tension for long span or extra
redundancy is needed, double/tandem gripping is
recommended. Conductor uses 0-temper aluminum withdiamter below 24 mm should be double gripped.
Rubber hose protection

5.16. If the conductor must be left in the sheaves for an extended
period of time (more than 72 hours), it should be left at atension less than 50% of sagging tension (close to pulling
tension). Loose tension poses big swing risk in strong windwhich causes conductors to clash each other or moving backand forth on sheaves. Conductor on sheaves may be
temporarily fixed to keep it from moving back and forth on
sheaves which can cause nicking the outer aluminum
strands or damaging the core of conductor (this is especially
important for smaller diameter conductor with lighter
weight).

6.

6.3.

6.5.

To keep the conductor surface from scratching with wires,
it is recommended to protect the conductor surface withwraps of rubber hose. This is particularly important for
conductor with soft 0-temper aluminum.

6.6.

For Pocketbook-type grips, the nuts used to close the grip
must be free-running. The bolts must be properly tightenedwith full torque recommended by the manufacturer.

SAGGING
Conductor Grip: It shall be assured that the grip does notover-tension or deform individual wires and capable ofholding the conductor to the highest tension that is

anticipated during the sagging operation. (Any grips,
which transmit excessive crushing force to the core,should not be used.)
6.2.

Klein “Chicago-type” grips are recommended. Grips
must be properly sized for the conductor diameter. Lengthof jaw is recommended to be 170mm+ for conductor

Pocketbook type Grip

diameter 22mm and smaller and 270mm+ for bigger
conductors. In case that conductor uses 0-temper
aluminum, Klein Chicago grip tool guide (for ACSS
which also has 0-temper aluminum) should be
followed.

Klein “Chicago-type” Grip

9

6.7.

It is recommended to take a section of conductor to beinstalled and, test the holding strength of the grips using
chain hoist and dynamometer to verify grip holding strength.
The Grip should not slip when subjected to a minimum
tension of 150% of the working tension during installation.

6.8.

ACFR can tolerate drape slack from conductor grip however,this would be unacceptable if the conductor is tensioned or ifthe crew were pulling the conductor tail to install a fitting to
be installed on the ground. In case that installation of ACFR
Dead-end clamp takes place on the ground, caution shall be used
to avoid sharp local bending of the conductor at the grips. Fullsize sheave should be used in between conductor grip andpulling to avoid excessive bend.

6.9.

6.11

Placing a sheave a full size sheave (20 x Dc) next to the
conductor grip (3meters away and slightly below
conductor grip) can avoid excessive local bending
during installation of dead-end on the ground. It is okay
to drape slack the conductor across small roller but itwould not be acceptable if the conductor were bent
sharply under tension. It must be assured that bendingof the counductor is round in case of pulling down
the conductor to the ground.

Always avoid sharp local bend at the conductor grip.
Excessive bending can cause opening of aluminum strands.
In case of that conductor damage includes evidence of overbending, kinking, or crushing, the suspect section should be
replaced with new conductor.

6.10. Conductor end must be ALWAYS supported during
splicing to avoid sharp bending of conductor.

Installation of deadend clamp on the ground

Installation of Deadend clamp on the tower

10

7.

SPLICING AND ACCESORIESUpper/Bottom
die must matecompletely to
avoid curvature✓×
Aluminum buffer insert OR Bottom (soft) aluminum layer is used to grip the cfcc core.
Installer must Check manufacturer’s recommendation

7.1.

ACFR uses compression type splicing that is similar to
ACSR. Notable difference is that ACFR uses soft aluminum
buffer components which grips the CFCC core inside innersteel sleeve (either inserted type buffer or bottom layer ofouter aluminum layer is used to grip the core).

7.2.

Installer must check installation procedure as per
manufacturer’s recommendation.

7.3.

Conventional compressor and dies used for ACSR can beused for installation. Across-flat width after compression
should be checked for both inner and aluminum sleevein accordance with manufacturer’s recommendation.

7.4.

7.5.

11

Direction of compression must be checked as per
manufacturer’s recommendation. Reverse compression(from tower to conductor) should ONLY be used whenclearly specified. Pressure must be checked as per
requirement and it must be assured that die surfaces matecompletely for each press. Insufficient compression can
result in slippage/failure. The slight loosening of aluminum
wires (which is unavoidable when compression the fitting)will move into the span later (and is not a problem) after
tensioning and energizing. Note that there is added space
for the aluminum to move towards the steel eye whenreverse compressing in this case. Jumper socket for ACFR
conductor is compression type similar to ACSR and CFCC
gripping component is not required.

7.6.

7.8.

Cutting the conductor: stripping of aluminum layer shallbe done by cable trimmer. The bottom layer shall be
stripped by repetitive bending fatigue only. The final
cutting of the core must be done by fine-tooth hacksaw or
disk cutter to produce a clean cut. The core shall never benicked or scratched during the stripping. Hydraulic cutter
can be used for rough cutting but should not be used for
cutting the core. Rough edges of the core may be removed
by metal file.

Full sized hold-down/let-up block should be used to avoid
excessive bending during holding down and/or letting up
the conductor before and/or after the installation of midspanjoint. DO NOT USE NARROW SLING OR ROPE.

✓

Taping✓Use Hold-down \ Let-up block to avoid sharp bending

7.9.

7.7.

Typical ACFR suspension clamp is armor-suspension
clamp. The main body is of cast iron or aluminum alloy andthe conductor is wrapped with heat-resistant rubber, and theholding metal fittings are tightened with bolts while thearmor rod is wound. Appropriate wire lifting hook must
be used when transferring the wire from the runningsheave to the suspension clamp to prevent local bending.

Midspan Joint

Length of midspan joint for ACFR is longer than ACSR.
midspan joint are normally installed only after
conductor has been pulled into position.
Triangle frame hoist for lifting conductor for suspension clamp

Installation of midspan joint on the ground

Installation of Armor rod and suspension clamp12

7.10. Aerial vibration on ACFR conductor can be mitigated withinstallation of vibration damper just like any other conductor.
Dampers can be stock-bridge or dog-bone type or spacer
damper type. Installation procedure as well as required tools
such as bolt fastener must be checked as per manufacturer’s
recommendation. Dumper and the use of the armor rod must
be approved for 0-temper aluminum. Damper quantity andspacing shall be as per manufacturer’s damper placement
chart. Armor rod must be properly installed to protect the
conductor strand from fatigue breakage.
7.11. In case that armor rod is used for the vibration dumper, it
must be assured that there is more than 800mm-1000mm
spacing between the edge of armor rod and theDeadend/Suspension clamp as to allow the aluminum
strands to move to avoid fatigue breakage of aluminum
strand caused by aeolian vibration or galloping of the
conductor.

8.2.

The stranded design of the CFCC core makes it structurally
redundant and gives practical handling characteristic andmore durability to the conductor. The unfortunate event ofsnapping of conductor due to core failure is restricted as thedamage (if any) can be restricted without compromising thestrength of the whole core.

8.3.

Abrasion Damage can be identified by observing black
deposits on the conductor strand which is caused by relative
movement between conductor hardware and the conductor.
Ensure that the cause of the abrasion is identified andcorrected or it can result in failure of the conductor strands.

8.4.

Assure that installed line hardware and accessories are
not missing split pins, bolts or nuts and securely fastened as
per manufacture’s recommendation. Rusty/corroded
hardware must be replaced.

9.

8.
8.1.

9.1.

Repairing of conductor surface shall be done only in caseof minor damage, scuff marks, etc., keeping in mind bothelectrical and mechanical safety requirements.

9.2.

Conductor distortion and minor birdcage can often be
repaired by hand reshaping with a small block of wood andtapping the loosen strands out into the open span.

9.3.

Repair sleeves may be used when the damage is limited tothe outer layer only and does not affect more than one sixthof the strands of the outer most layer. No repair sleeve shallbe fitted within 30 meters of tension or suspension hardware
fittings. (More than one repair sleeve per conductor should
normally not be permitted in any one span.)

Damage Consideration
Distortion of Aluminum. In case that opening ofaluminum strand, birdcage, squeezing, or kink is seen, it
should be evaluated for the possibility of damage to the core.
Damage to the composite core caused by excessive bending
and twisting during installation can often be identified bydeformation in the aluminum strands. CFCC core is flexible
and can take bending to some extent and less likely to bedamaged without aluminum deformation except in the casethat the conductor was strung with tension throughundersized sheaves. If the evidence of over-bending,kinking, or crushing, the suspect section should be repairedor replaced with new conductor.

REPAIR

Strand opening due to sharp “local” overbending

10. REFERANCES:
10.1. IEEE 524 Guide for the installation of Overhead Transmission line
Conductors (2016)

10.2. IEEE 516 Guide for Maintenance Methods on Energized Power Lines(2003)

10.3. Power line safety 1926.1409 Occupational Safety and Health(single hook hoisting with tension)

Administration (2010)

10.4. TLT-5 Kasen-kouji Gijyutu Kaisetsu, Denki-Shoin (2010)
10.5. Japan TX Line Construction Committee (Soudensen-Kensetsu-Gijyutsu-

Strand distortion due to “concentrated” overtwisting(270°rotation squeezing of 1 m specimen)

Kenkyukai) No.22 (Dec.1994)

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11.3. TENSION SITE

11. PUNCH OUT LIST (✓)A)

The break over angle at the first sheave is reduced<30 °and/or an oversized sheave is used?

The intended conductor route is thoroughly inspected forspecific locations of bend and any obstacles and crossings(such as trees, billboards, existing lines, highway, etc.) aretreated in such a way that conductor will not be over-bent,
twisted, dragged or pulled across over obstacles?

B)

The tension site is located in a position allowing the
conductor to be pulled straight to the first structure?

C)

Drum – Tensioner is positioned in a manner that the
conductor will not be over-bend or twist?

B)

Suitable crossing support structures/scaffoldings are used
when obstacles like line, road, rail etc. are to be crossed?

D)

The Tensioner Feed Sheave has been installed between
drum and tensioner?

C)

Have the entire stringing crew been familiarized with thehandling parameters and work procedures?

E)

The conductor is fed through the center of the tensioner feed
guide roller without bending?

D)

Drum Storage and Transportation is carried out in a manner
not to damage the conductor?

F)E)

A sample of each type of ACFR conductor’s midspan joints/ dead-end assemblies have been tested for tensile strengthin accordance with customer requirements and approved?

Braking on the drum is kept steady and minimum
necessary? (Slight droop between drum and tensioner feedsheave indicates correct back tension).

G)

The conductor drum is not free spooling?

H)

Approved Hardware and Fittings (Dead-end clamp, Jumper
terminal Suspension clamp, Spacer, Damper, Armor rod,
Aircraft warning sphere, bird-diverter etc.) have beendelivered with the manufacture’s recommended Installation
procedure?

The conductor is ready for consistent and smooth payout
without bouncing or jumping?

I)

The Grounding Block is installed?

J)

Anchorage for the Drum stand and the Tensioner (> 2.5 xworking back tension) are installed?

K)

The payoff conductor is not being twisted on the side of thegroove?

L)

The rewinding of the conductor is carried out in a way thateach wrap of the conductor does not cross over?

11.1. PREPARATION
A)

F)

G)

The planned pulling tension is < 10% Conductor RTS? If
not, it shall be assured that pulling tension does not exceed
50-70% of sagging tension.

11.2. RUNNING SHEAVESA)M) A swivel is installed between the old conductor and new
conductor?

All the pulling angles at tension towers have been checked
for more/less than 60° for sheave selection?

N)

ACFR Midspan splices are NOT to be INSTALLED at
tension site? as splices are normally installed after the
conductor has been pulled into position (unless specialized
splices and procedures are certified to facilitate safe, reliableinstallation.).

O)

Are sizes and rating of the wiremesh grip correct? Up tothree drums joined by proper wire mesh grip may be pulled
back-to-back if the site conditions don’t allow proper
access. As a guideline, pulls should not be more than 20
spans.

B)

Min. Sheave Dia. > 20 x Dc are selected for pulling angles <
60°?

C)

Oversized or Multiple Roller Sheaves are selected forlocations with pulling angle > 60°?

D)

All the Running Sheaves are properly lubricated and lining
on the grooves are in good condition to ensure smooth
traveling of the conductor?

E)

Are the sheaves at the suspension towers installed inoffsetting position to avoid unnecessary contact between
conductors?

F)

Oversized Hold-Down/let-up sheave are selected for
installation of midspan joint not to allow overbending?

A)G)All the running sheaves at angles are rigged up to align with
conductor pass so that conductor runs on the center of thegroove?

Is the planned pulling section < 3 drum and/or 20 spans? Or
specialized arrangement/procedures has been certified tofacilitate reliable installation?

B)

Radio Communication is maintained and; Designatedwatchmen are positioned at angles/obstacles to monitor andreport traveling of conductor?

C)

Support structures and rollers are installed to prevent the
conductors to come into contact with the obstacle andwithout dragging or sharp bending.

D)

Support structure/scaffolding is constructed in such a way as
not to cause sharp bends of the conductor?

H)

Are all the installed sheaves diameter equal to or larger thanrequired?

I)

Necessary Support/Back stay for Tower Cross arm areinstalled?

11.4. STRINGING

14

E)

All the tension bearing equipment such as pulling wire,swivel/fixed joint, connecting wire, mesh grip etc.) is rated
for >2.5 x stringing tension and selected in a manner tominimize torsional stress?

F)

Is pulling wire/anti-twist wire in good condition without
kink/damaged strand?

G)

Connecting wire between conductor is in same laying
direction as the conductor?

H)

I)

The sag is double-checked with sag scope and meeting clearance
requirement?

J)

The conductor is fixed on the sheave not to move in case it willbe left on sheaves over extended time?

11.7. CLAMPING (Tension)A)

The outer aluminum layer is removed by Cable
trimmer and repetitive bending to keep the CFCC
intact?

Correct counterweight is installed and the conductor is not
rotating inside?

B)

The Conductor End is supported not to allow sharp
bend?

I)

The wire mesh is securely joining to the conductor with coreretainer?

C)

The CFCC core is cut by fine tooth hacksaw to
produce a clean cut?

J)

Tensioner operation is preceding to maintain constant backtension?

D)

Direction of press (conductor ←→ tower) is
confirmed as per manufactures recommendation?

K)

The conductor is not over twisted during the pull?

E)

L)

Reporting Overbent / Twisted section of ACFR?

The exposed CFCC portion is kept straight andundamaged (no bend or twist) during splicing
activities?

F)

The filler compound is fully injected without leaving
air voids/gap inside the sleeves?

G)

Across-flat-width for dead-end inner/outer sleeve
after compression is double checked withM) Avoiding pulling the conductor above sag height?

11.5. MIDSPAN JOINT SPLICINGA)

B)

When installing midspan splicing on the ground, Full size
Hold-down / Let-up block are used to avoid sharp bendingof the conductor? rope should never be used to pull down
conductor as to avoid sharp bending of the conductor.

compression gauge?

Step-by-step installation procedure has been confirmed andunderstood as per hardware manufacture’s
recommendation? (check compression/non-compression are
and direction of press)

H)

Jumper drop is as per drawing to meet theminimum clearance requirements?

I)

The bolts of jumper connection are properly
fastened?

11.8. CLAMPING (Suspension)
11.6. SAGGING
A)

B)

C)

A) Lifting of the conductor to install the suspension
clamp is done in a manner not allowing sharpbending?

The Conductor Grip is tested not to cause aluminum
distortion or slippage when tensioned with 150% working
tension prior to the use?

B) The armor rods are installed to match the center ofplumb mark?

Conductor is to be pulled up to scheduled sag within 24
hours of installation and clipped in within 72 hours ofstringing?

C) The suspension insulators are hanged vertically?

Conductor uses 0-temper aluminum with diameter below 24mm is double-gripped?

D)

Double-Gripping technique is used for long spans (500m+)
and/or higher sagging tension spans?

E)

The workers participate in sagging and clamping activity
are fully familiarized with handling parameter? (Avoid local
sharp bend at grips and always support conductor end withropes)

11.9. VIBRATION DAMPER & SPACER

A) Are Positioning, Spacing and quantity of
damper/spacer as per manufacture’s recommendation/ placement chart? (Check long spans where extra
damper is required)F)

Is the dynamometer calibrated?

B) Vibration Dampers are hanging vertically and bolts are
securely fastened as per the manufacturer’s
recommendation?

G)

The scheduled sagging tension is within allowable loading
limit?

C) Is there more than 800mm spacing between the edge ofthe armor rod and the deedend clamp?

H)

Bundled conductors are all sagged at the same time to ensure
matched sag?

-End of Section-

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