Installation of lightning current

transfer unit
Document no.: 0079-9394 V01
Class: RESTRICTED
Type: T09
Date: 2020-01-08

VESTAS PROPRIETARY NOTICE: This document contains valuable confidential information of Vestas Wind Systems A/S. It is protected by copyright law as an unpublished work. Vestas reserves all patent, copyright, trade secret, and
other proprietary rights to it. The information in this document may not be used, reproduced, or disclosed except if and to the extent rights are expressly granted by Vestas in writing and subject to applicable conditions. Vestas
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Wind turbine type

Read the full document before you start to do work.

Send questions or concerns about the document to Vestas Wind Systems A/S.

Wind turbine type Mk version

V117-4.0/4.2 MW Mk 3E

V136-4.0/4.2 MW Mk 3E

V150-4.0/4.2 MW Mk 3E

Change description

Description of changes

Updated section 8 Spare parts, page 6.

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Table of Contents

1 Safety ........................................................................................................................... 4
2 Educational requirements of service technician .................................................... 4
3 Abbreviations and technical terms .......................................................................... 4
4 Referenced documentation....................................................................................... 5
4.1 Safety documents......................................................................................................... 5
4.2 Reference documents .................................................................................................. 5
5 Purpose ....................................................................................................................... 5
6 Note.............................................................................................................................. 5
7 Tools ............................................................................................................................ 6
8 Spare parts .................................................................................................................. 6
9 Consumables .............................................................................................................. 7
10 Weights........................................................................................................................ 7
11 Estimated time use..................................................................................................... 7
12 Procedure.................................................................................................................... 7
13 Procedure to lock the rotor ....................................................................................... 7
14 To discharge the static electricity in the blade...................................................... 10
15 To install the LCTU on the blade bearing................................................................11
16 To adjust the LCTU ................................................................................................... 13
17 To remove the lightning conductor jumper inside the blade............................... 14
18 To replace the spare parts of the LCTU.................................................................. 14
18.1 To remove the LCTU arms ......................................................................................... 18
18.2 To install the nacelle side and blade-side repair kit assembly ................................... 18
18.3 To install the electrical cable repair kit assembly ....................................................... 21
18.4 To install the repaired LCTU arms .............................................................................. 22
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1 Safety 0011465016

All work relating to a Vestas wind turbine, including work methods and practices, employee
training and protective measures, and use of tools and equipment, shall be in accordance with
the requirements of the applicable governmental and private occupational safety and health
codes and standards. Employers engaged in such work are also required to be familiar with and
comply with the wind turbine-specific ‘Safety regulations for operators and technicians’ manual
for the relevant wind turbine type. Vestas shall not be responsible for any liabilities arising from
failure to comply with such requirements. Vestas reserves the right to inspect such work to
ascertain such compliance.
The service technician must read and understand the PPE sheets for each of the chemicals used
or work done in this instruction. The PPE sheets describe the correct personal protective
equipment to wear for the specific work. If in doubt about the PPE requirements for the work,
contact the site responsible or the line manager and confirm the correct procedure before starting
the work.
For chemicals that are not specified with accurate name and item no., contact the local site-
responsible person for information about PPE and other safety instructions related to the use of
the chemical.

2 Educational requirements of service technician 0011465014

At least 2 of the service technicians who do work in a wind turbine must be able to prove that they
have a valid GWO basic safety training certificate.
At least 1 service technician must hold the wind turbine-specific training course certificate for the
wind turbine in question.
Some tasks require one or more advanced training modules or job-specific training, as described
in the Vestas technical training programme. The person who plans a specific task must make
sure that the service technicians involved have the proper know-how for the completion of that
task.

3 Abbreviations and technical terms 0011379267

Table 3.1: Abbreviations

Abbreviation Explanation
ERP Enterprise resource planning
GWO The Global Wind Organisation
HTq High torque
LTq Low torque
LCTU Lightning current transfer unit
SDS Safety data sheet
PPE Personal protective equipment
SBU Sales business unit
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Table 3.2: Explanation of terms

Term Explanation
None

4 Referenced documentation 0011439219

4.1 Safety documents 0020434330

Table 4.1: Safety documents

Document no. Title

Various Relevant SDSs for the chemicals used in this document
0001-0410 Personal protective equipment sheets
0004-4159 Standardised procedure risk assessment (SPRA)
0081-2529 Safety regulations for operators and technicians
0077-2293 Rotor locking system

4.2 Reference documents 0020434329

Table 4.2: Reference documents

Document no. Title

920098 Torque wrench settings
960501 Bolt connections
0081-5569 Lightning current transfer module description
0015-9531 Discharge of static electricity in blade
0080-2313 SIF for wind turbine installation
0065-3482 Standard service tools

Unless it is specified differently, see 920098 ‘Torque wrench settings’ for information
about bolt types and bolt lubrication, and see 960501 ‘Bolt connections’ for
information about torque values.

5 Purpose 0011379327

The purpose of this document is to give the procedure for how to replace and install both the
spare parts of the LCTU and the complete LCTU.

6 Note 0011379326

The procedure must be done for each blade.

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7 Tools 0020434328

For standard service tools, see 0065-3482 ‘Standard service tools’.

Table 7.1: Tools

Item no. Quantity Description

883462 1 Static electricity discharge kit
ERP: STATIC EL DCHARGE KIT BLADE T2
1 400 Nm Torque wrench with 46 mm socket
1 50 Nm Torque wrench with 13 mm socket
1 13 mm Fixed ring spanner
1 17 mm Fixed ring spanner

Some tools in this tools list can vary in shape and technical specification from region
to region due to local requirements.
If in doubt, contact your local tools warehouse for tool numbers applicable to your
region.
This note may not be applicable for any special tools used in this procedure.

8 Spare parts 0022340199

Table 8.1: Spare parts

Item no. Quantity Description

29099504 1 per blade ERP: SITE PARTS, LCTU FOR V117 DE
29060688 1 per blade ERP: SITE PARTS LCTU FOR V136
29112988 1 per blade ERP: SITE PARTS LCTU FOR V150
29112713* 1 per blade ERP: REPAIR KIT 4 - NACELLE SIDE
29112712* 1 per blade ERP: REPAIR KIT 5 - BLADE SIDE
29112707* 1 per blade ERP: REPAIR KIT 8 - CABLE

*) The repair kit is necessary when the service technician makes a decision to replace the spare
parts of the LCTU.

If the LCTU repair or replacement is necessary on all the 3 blades, then 3 repair kits
must be ordered.
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9 Consumables 0020434327

Table 9.1: Consumables

Item no. Quantity Description

221007 As ERP: ADHESIVE, THREADLOCK LOCTITE 243 50ML
necessary

10 Weights 0011409464

The weight of 1 complete LCTU is 7.7 kg.

The weight of 1 complete nacelle-side repair kit is 0.4 kg.
The weight of 1 complete blade-side repair kit is 0.4 kg.
The weight of 1 complete cable kit is 0.5 kg.

11 Estimated time use 0011409463

The time required to replace 3 LCTUs is 3.5 hours for 2 service technicians.
The time required to replace the spare parts of the LCTU is 3 hours in total for 2 service
technicians (1 hour for nacelle-side repair, 1 hour for blade-side repair, and 1 hour for cable
repair).

12 Procedure 0017187865

Visually examine the LCTU to find if replacement of the spare parts or replacement of the
complete LCTU is necessary.
If repair of the LCTU is necessary, do a visual inspection to find the repair kit that must be used
(blade side, nacelle side, or electrical cable). It can also be necessary to use all the kits to do the
LCTU repair.

13 Procedure to lock the rotor 0021303543

To secure the rotor locking pins!

• Do not try to lock the rotor when the rotor turns.
• Always engage the high-speed brake before you lock the rotor.
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Figure 13.1: Rotor locking system

1 Engage the HS brake.

2 Examine the transparent part (2) of the main

shaft cover (1) to align the rotor lock marks.
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3 Release the HS brake to adjust the rotor to

align the rotor lock marks (1).

4 Engage the HS brake when the rotor lock marks are aligned.

5 Lift the bracket (2) to operate the lever (1).

6 Move the lever to position A (1) to engage

the rotor locking pins.
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7 Use the hydraulic hand pump to engage the

rotor locking pins (1).

8 Do a visual inspection to see if all the 3 rotor locking pins are fully engaged.

9 Do the LOTO procedure at positions (1) and

(2) to secure the lever at position A.

14 To discharge the static electricity in the blade 0011379320

Risk of exposure to electric shock! SPRA ID No. 3.10

• Use the earthing connection to discharge the static electricity.
• Use an HV/LV voltage detector to measure zero voltage before you start to do the
work.
• Use certified and correct tools and equipment.
• Use the necessary PPE that is given in PPE sheet 7.

Discharge of static electricity must be done according to instructions in 0015-9531 ‘Discharge of

static electricity in blade’.
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15 To install the LCTU on the blade bearing 0011379269

• The LCTU blade side arm and the LCTU nacelle side arm must be removed to tighten the
nuts on the support for the LCTU.

1 Use an isolating stick to connect the discharge cable to the earthing bolt on the blade.

It is also possible to install the LCTU without removal of the earthing bolt. Push the
LCTU installation bracket (1) against the blade bearing nuts to install the LCTU.

2 Remove the bolts (1) from the plate of the

LCTU blade side arm (2) and the LCTU
nacelle side arm (3).

The LCTU must be installed on the blade bearing directly below the spinner
assembly.

3 Install the support for the LCTU (3) on top of

the stud nuts (1) of the blade bearing (2).
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• The support for the LCTU must be installed in parallel to the hub flange.

4 Attach the LCTU installation bracket to the

bolts (1), which are located directly below the
spinner assembly (2).

Risk of exposure to hazardous substances and mixtures, adhesive

threadlocker Loctite® 243TM! SPRA ID No. 2.02
• May cause an allergic skin reaction. Toxic to aquatic life with long-lasting effects.
• Use the necessary PPE that is given in sheet E. Read and obey the related SDS.

5 Apply thread-locking agent to the threads of the stud bolts.

6 Install the nuts on the support for the LCTU.

a Torque the nuts to 400 Nm.

7 Install the LCTU blade arm and the LCTU nacelle side arm again.

a Tighten the nuts according to ‘Bolt connections’.

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16 To adjust the LCTU 0011379349

1 Check that the wear pad (1) of the LCTU

nacelle arm is aligned with the nacelle
lightning ring.

a If necessary, loosen the wear pad to adjust the angle.

2 Pitch the blade from outermost to innermost position, (begin with the pitch actuator in its
outermost position).

3 Check that the wear pad of the LCTU blade arm is not in contact with the earthing bolt of the
blade.

a If necessary, move the wear pad by loosening the LCTU blade arm.

4 Remove the discharge cable.

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17 To remove the lightning conductor jumper inside the

blade 0011379348

Risk of fall into the blades from open manholes! SPRA ID No. 1.08
• Only remove the manhole covers for the blade bearings when the service
technicians have attached personal fall arrest equipment to an approved anchor
point.
• If there is only one manhole cover in the hub, it must be installed on the blade that
points downwards, before you remove the personal fall arrest equipment.
• Use the manhole cover to secure the opening which points downwards.

1 Remove the cover on the manhole in the blade bearing.

2 Remove the lightning conductor jumper (1)

between the lightning receptor screw in the
blade and the torque arm plate.

3 Reinstall the cover on the manhole.

4 Store the lightning conductor jumper in the nacelle for later use during maintenance of the
LCTU.

18 To replace the spare parts of the LCTU 0017147321

The LCTU repair kits are supplied as pre-assembled units with lock pins in the package. The
figures that follow give an overview of the LCTU repair kits.
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Figure 18.1: Nacelle-side repair kit

1* Wear pad 2* Lightning rod

3* Rod mounting plate 4* Rubber bushing
5 Lock pin 6* Seeger ring
7* Shaft

*) The spare parts are part of the pre-assembled unit.

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Figure 18.2: Blade-side repair kit

1* Wear pad, round 2* Lightning rod

3* Rod mounting plate 4* Rubber bushing
5 Lock pin 6* Seeger ring
7* Shaft
*) The spare parts are part of the pre-assembled unit.
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Figure 18.3: Cable repair kit

1 Screw hex (ISO 4017 M8x20 A4-70) 2 Wedge lock washer (M8 A4)
3 Cable for LCTU (50MM2 L=275MM)

Torque all the M8 bolts on the LCTU to 17 Nm.

Torque the M8 bolts that hold the cable to 15 Nm.
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18.1 To remove the LCTU arms 0020528827

The bolted connection is on the lightning conductor band.

1 Install the lightning conductor jumper (1) in

the blade on the bolted connection and then
to the stiffener plate.

a If the LCTU is broken, install the discharge kit. See ‘Discharge of static electricity in
blade’ document in reference documents section.

2 Remove the LCTU arm (both nacelle side (1)

and blade side (2), if necessary) to prepare
for the replacement of spare parts.

18.2 To install the nacelle side and blade-side repair kit assembly 0017483693

1 Visually examine the LCTU to make sure that the spare parts replacement is necessary to
do the LCTU repair.

a Replace the complete LCTU as given in section 15 To install the LCTU on the blade
bearing, page 11, if spare parts replacement is not necessary.
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2 Loosen and remove the M8 bolts (1) and

washers (2) from electrical cable (3) to
remove the electrical cable.

a Remove the 2 M8 bolts (1) and washers (2) from the LCTU arms, if the nacelle-side
LCTU arm and the blade-side LCTU arm are to be replaced.

3 Remove the 4 lock pins from the nacelle-side or the blade-side LCTU arm to remove the
wear pad assembly from the LCTU arms.

• Lock pin (1) removed from the nacelle side LCTU arm (2).

• Lock pin (1) removed from the blade side LCTU arm (2).
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4 Remove all the 4 rubber bushings (1) from

the LCTU arm (2) after you remove the lock
pins. Visually examine to make sure that no
material is in the LCTU arms holes.

5 Remove the used wear pad assembly from the LCTU arms.

• Wear pad assembly (1) on the nacelle side LCTU arm (2)

• Wear pad assembly (1) on the blade side LCTU arm (2)

6 Install all the 4 new rubber bushings on the LCTU arms.

7 Prepare and install the new wear pad assembly on the LCTU arms.
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8 Use the 4 lock pins (1) to attach the nacelle-

side wear pads assembly (2) and the blade-
side wear pad assembly (3) on the LCTU
arms (4).

9 Visually examine to make sure that the wear pads assembly are correctly installed on the
LCTU arms and are not loosened.

18.3 To install the electrical cable repair kit assembly 0017483692

1 Visually examine the LCTU to make sure that the spare parts replacement is necessary to
do the LCTU repair.

a Replace the complete LCTU as given in section 15 To install the LCTU on the blade
bearing, page 11, if spare parts replacement is not necessary.

2 Loosen and remove the 2 M8 bolts (1) and

washers (2) from electrical cable (3) to
remove the electrical cable.

3 Prepare and install the new cable repair kit.

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4 Use the 2 M8 bolts (1) and washers (2) to

attach the new electrical cable (3) on the
LCTU arms.

5 Make sure that the M8 bolts are torqued to 15 Nm.

18.4 To install the repaired LCTU arms 0017169508

1 Install the repaired LCTU arms (nacelle side

(1) and blade side (2)) on the LCTU
mounting bracket and tighten the M8 fixation
bolts (3) to prepare for the LCTU installation
closure.

a Torque the M8 fixation bolts to 17 Nm.

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Risk of severe crushing injuries! SPRA ID No. 5.11

• Vacate the hub during movement of the pitch system.

Keep a safe distance (3) from the slider unit and bolt.

2 Pitch the blade from -5° to 90° to make sure

that the bolt on the stainless steel rim (1)
does not hit the wear pad (2).

3 Loosen the M8 fixation bolts (1) and adjust

the LCTU arms (blade side (2) and nacelle
side (3)), if the wear pads hits the bolt.

4 Torque the M8 fixation bolts again to 17 Nm.