High current is a hazard to the turbine and technicians alike. For the turbine, lightning strikes can damage blades and short out electric equipment when not sufficiently grounded. There are ways to handle the high current in lightning. Inside the nacelle, technicians have to diagnose issues to get troubled turbines back into production as soon as possible. Several new smart electrical meters can assist that work.

1. KeepingTurbines and Workers
Safe With Lightning Diverters
and Electric Meters

2. Thank You To Our Sponsor

3. Before We Start
q This webinar will be available at
www.windpowerengineering.com & email
q Q&A at the end of the presentation
q Hashtag for this webinar: #WindWebinar

4. Moderator Presenters
Paul Dvorak
Windpower Engineering
& Development
Greg Shine
Shine Wire Products
Jeffrey Jowett
Megger
Allen Hall
Pinnacle Lightning
Protection

5. Intelligent Safety
Under Pressure?
Tired?
No Time to finish
the job?

6. Safety must be
considered from:
• The tester
• The test item

7. Test Instruments:
• Insulation Tester
• Power Factor
• Winding Resistance

8. The Tester:
Despite high voltage, insulation testers are safe.
Current and power are small.
To test insulation, you don’t NEED a lot of current.
Hence, total current output can be kept small.
BUT, be aware of the physical environment.

9. The Tester:
Redundant safety features –
IEC61010 arc flash/arc blast protection
Safety warnings and indicators
Safe design of test leads

10. The Test Item:
De-energized is not “safe”.
Standard Safety Practices
Lock-out/tag-out
Safety enhancements in quality testers:
Discharge test item
Let operator know

11. Safety Standards:
• IEEE 62-1995
• IEEE C57.152
• IEEE 510-1983
• IEEE Recommended Practices for Safety in High-
Voltage and High-Power Testing

12. Insulation Test Currents
1
1
Capacitive Charging
Current
Total
Current
Conduction or
Leakage Current
Current -­‐‑ Microamperes
Seconds (x10)
Absorption
Current

13. Insulation Test Currents
Equivalent Circuit of Insulation
Leakage
Absorption Capacitance

14. Polarization/Absorption
Effects
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Stored Charge
Surface
Leakage
Dipoles

15. Safety Rating - IEC
• Dictates design considerations - ensure instrument is
adequate for hazards of test environment.
• IEC1010 rating consists of two designations; make sure
both are specified:
- CAT (category).
- voltage.
• Determine the highest-rated environment where the
instrument will be used.
• Do not buy an instrument without a rating.

16. High Installation CAT rating
• MIT & S1= CATIV 600V rated • IEC1010-1:2001
• Protection against
input transients
between any
terminals
• CATIII 300V
• 4kV transient
protected
• CATIV 600V
• 8kV transient
protected

17. Safety philosophy
• What happens in substations?
• CATIV 600V in a 33kV substation means little….?
• 5kV and 10kV insulation testers get used where 1kV
testers don’t
• No one can protect against foreseeable misuse here!

18. Standard Safe Working
Practices
• Boots & Gloves
• Barriers
• Beacon

19. CAUTION: Inductive Source
• Safety grounds
• Voltage indicator
• Discharge stick
Make 1st/break last

20. Power Factor = Redundant
Safety
• Hand/foot interlocks
• Dual ground testing
• Circuit breaker protection
• Grounded between tests
• High voltage and open ground indicators
• Arc clearance

21. Advanced Microprocessor controlled System protects user and
instrument in the event of accidental connection to live systems
• Contact Detector - Prevents free probe becoming live if other probe contacts live voltage.
• Live Circuit Warning - Warns if probes connected to >25V
• Test Inhibit - Prevents tests when dangerous external voltages exist
• Auto-Discharge -Safely discharges connected circuits after insulation test
• Default Voltmeter - Displays external voltages even when switched to non-voltage ranges
Beware of lesser Systems!
Intelligent Safety System

22. Contact Detector
Concept
• Maintains High Impedance between probes until safe contact is
made with the circuit under test.
Benefits
• Increased Safety - User will not receive a shock if one probe
accidentally contacts a live circuit.

23. Contact Detector -
Additional Benefits
No fuse blowing - (Some instruments can blow their internal fuses if voltage
present between the points tested):
• Difficulty finding replacements and wastes time
• Voids calibration seals if instrument has to be opened
The contact detector’s high impedance state leaves the fuse intact.
Even then…
• A replacement is provided in the battery compartment
• The instrument case does not need to be opened,
(calibration seals remain intact)

24. 1. Safety! – the big issue
• High energy environments?
• Concern over receiving shock from instrument
• The danger is actually the after effects
Don’t Overlook Leads:
Large finger guards
to keep fingers back
from live parts
Side Pivot guards
maintain creepage
paths
Pivot guard
maintains
clearance
Large finger guards
to keep fingers back
from live parts
Side Pivot guards
maintain creepage
paths
Pivot guard
maintains
clearance
Finns increase surface
creepage distance
Finns
Finns increase surface
creepage distance
Finns

25. Keeping Turbines and
Workers Safe with
Lightning Diverters
Allen Hall – Pinnacle Lightning Protection, LLC
Greg Shine – Shine Wire Products, Inc.
WXGUARDWIND.COM

26. Lightning Damage to
Turbine Blades
• Lightning strikes account for roughly 25% of loss claims in
US
• Most lightning damage occurs to blades
• Blade claims average 240,000 USD

27. Typical Blade Designs

28. Typical Blade Protection

29. Typical Lightning Strikes
• Most strikes occur within 4 to 5 meters of tip
• Peak currents of 5 to 20 kA
• IEC 61400-24/62305-1
o 200kA
o 10 MJ/ohm

30. Lightning Receptors

31. Inside the Blade Tip
Receptor
Metal
Mounting
BlockDown
Conductor

32. Electrical Breakdown
Around Thunderstorm
High Voltage
Electrical
Activity at
Mounting Block
Damage to
Blade
Structure

33. Near Strikes
Polytechnic University of Catalonia in
Barcelona, Spain
• Electrical activity at nearly
every rotation of blade
• Duration
o Few minutes
o Few hours
• Effects seen with storms
several kilometers away

34. Near Strikes
• Most lightning damage to blades occurs over time
• Near strikes break down blade dielectric around receptor
• Eventual lightning attachment results in more damage to
blade

35. Receptor Enhancement
• Need larger receptors on blade exterior to protect structure
• Difficult to achieve on blade in the field
Receptor
larger than
Metal Mounting
Block

36. Segmented Lightning
Diverters

37. Typical Installation
Lightning
Receptors
Internal
Down
Conductor
WXGuard
Lightning
Diverters

38. Segmented Diverter
Operation
Ionized
Channel Above
Diverter Glass Fiber Reinforced
Plastic Blade SurfaceSegmented
Lightning
Diverter
Receptor
Down
Conductor
Metal Segments
of Diverter
Mounting Block

39. Size Comparisons
Reference IEC 61400-24
Metal Segments
1.5 - 3 mm Diameter
0.2 mm Thick
Flexible Substrate
0.25 mm Thick
10 mm Wide
8 mm Diameter
Copper Cable
2 mm Thick
Copper Tape
WXGuard Diverter
25 mm Wide

40. Repeat Strike Capability
High Current Sample 3 Strikes
230 kA
8.5 MJ/ohm
Diverter Intact After 3 Strikes

41. Rain Erosion
Standard Segmented Diverter WXGuard Diverter

42. Segmented Diverter
Benefits
• Improve protection to existing blades
• Lightweight and flexible
• Installed with standard epoxy or 3M VHB Tape
• Repeat strike capable
• Rain erosion resistant

43. Thank You
• Visit WXGUARDWIND.COM
• Free White Papers
• Free Test Reports
• Free Installation Guide

44. Questions?
Paul Dvorak
Windpower Engineering & Development
pdvorak@wtwhmedia.com
Twitter: @windpower_eng
Greg Shine
Shine Wire Products
gshine@shinewire.com
Allen Hall
Pinnacle Lighting Protection
Allen_l_hall@pinnaclelightning.com
Jeffrey Jowett
Megger
Jeff.jowett@megger.com

45. Thank You
q This webinar will be available at
www.windpowerengineering.com & email
q Tweet with hashtag #WindWebinar
q Connect with Windpower Engineering & Development
q Discuss this on the EngineeringExchange.com