How To Clean Wind Turbine Slip Rings Most Effectively

Regular maintenance of the slip rings ensures that wind turbines operate efficiently. Neglected slip rings can lead to system failure, resulting in the breakoff of communication and signal transmission.

Significance of Slip Ring Cleaning

Over time, after several operations, slip rings accumulate grease, dust, and debris. An increase in resistance, signal transmission interruptions, and increased wear and tear are the results of accumulated dust and dirt. Slip rings need clean contact surfaces for smooth signal and current flow.

Regular slip ring cleaning ensures that electricity and signals flow smoothly between the blades and the control systems. Dirty slip rings can cause unplanned downtimes, which cost time and money to repair. Maintaining a regular cleaning schedule helps prevent the accumulation of dust and debris, ensuring the turbine continues to operate smoothly.

Different wind turbines accumulate dust not always the same.

● Location: Offshore turbines are more exposed to extreme weather and salty air and get dirtier faster than onshore ones. However, onshore turbines located in farms or deserts tend to accumulate dust more quickly.

● Humid and salty air: A lot of humidity and salty air causes dust to stick faster to the slip rings. Salty air accelerates the process of rusting and oxidation, leading to increased wear and reduced conductivity.  

● Age of the turbine: Older turbines tend to have worn-out covers that may not adequately protect the slip rings.

● Environment: Wind turbines located in polluted or dusty areas tend to accumulate more dirt, soot, or sand.  

How to Prepare Before Cleaning?

Before starting any cleaning process, we recommend reading through the manufacturer's manuals or guidelines. Different manufacturers have specific cleaning recommendations.

Power off and disconnect the machines before beginning the cleaning process to prevent electric shocks.

You can use the lockout/tagout procedure to ensure that the turbine does not restart during the cleaning process. The procedure involves placing locks and warning tags on switches and control panels. Confirm that the turbine rotor has stopped running.

The workers doing the cleaning should wear personal protective equipment (PPE). By wearing insulated gloves, the workers will protect their hands from electrical parts and sharp edges. To shield their eyes from dust and dirt, safety goggles are essential. Finally, anti-static clothes will prevent damage to sensitive parts.

Tools Required for Cleaning Process

Before starting on the cleaning process, it is essential to check the weather, especially if you’re working on outdoor turbines. Ensure the nacelle (which holds the main components of the wind turbine)is clear and dry. Collect the following tools and start the cleaning process.

Type of Tool Description

Step-By-Step Cleaning Process

Step 1: Prepare the Workspace

Inspect the slip rings to gauge the amount of dust and debris, as this determines the extent of cleaning required.

Using a soft microfiber cloth, wipe away dust, grease, and debris from the components surrounding the ring slip. Clean the surrounding components too to prevent contamination of the slip rings during the cleaning process.

Step 2: Apply Cleaning Solvent

Take a lint-free cloth and moisten it with a non-corrosive, industry-approved cleaning solvent. Apply the solvent evenly to the slip ring, ensuring it is not dripping wet to prevent moisture from causing electrical issues.

Wait for the solvent to penetrate well. Gently wipe the slip rings to remove grease, dust, grime, and some oxidation.

Step 3: Scrub the Surface

A bit of brushing is also essential to reach the grooves, ridges, and textured areas that you couldn’t get with the cloth.

However, to avoid damaging the plates and coatings, avoid brushing aggressively. Clean following one direction to prevent spreading the dirt and debris.

Step 4: Wipe the Slip Ring

Fortunately, isopropyl alcohol dries up quickly. However, we recommend using a lint-free, dry, soft cloth to wipe off any remaining loose debris. Wiping using smooth, even motions helps to avoid leaving streaks.

Step 5: Inspect the Slip Ring

Carefully inspect the dried slip rings while looking for signs of oxidation, scratching, contamination, or damage. Reapply the solvent on the piece of cloth and wipe the slip rings again to remove any remaining dirt and oxidation.  

Report any damage and contamination to maintenance.  

Step 6: Lubricate the Surface

Apply a lubricant only if the manufacturer recommends it, and the slip ring is clean and dry. Lubrication helps to reduce friction and future buildup. Use a high-quality lubricant to prevent damage to the slip ring.

Over-lubricating attracts dust, which can cause further damage. To choose the right type and amount of lubricant, follow the manufacturer’s recommendations.

Step 7: Recheck and Clean Surrounding Area

Leave the workspace just as clean as you found it, wiping away any spilled solvent. Collect all the used cloths and brushes and dispose of them. Do not leave any tools or liquids behind, ensuring the workspace is clean.

Clean surroundings help prevent future contamination while keeping it safe for other workers.

Step 8: Quality Inspection

Perform a last inspection of the slip ring to confirm it is clean and clear of any grease or debris. Verify that the surrounding components are clean and in the correct position.

In the maintenance log, record the inspection results and any repairs or problems you find. Documentation helps with future service and proves that the work was done correctly.

Common Problems During the Cleaning Process

Unfortunately, a few mistakes can occur when cleaning the slip rings. Using the wrong solvent can corrode the metal parts or leave a sticky residue behind. If any moisture remains on the slip rings, it can lead to corrosion or electrical faults. Moisture can also attract dust, leading to future buildup.

Excessive lubrication can cause the brushes to slip, thereby affecting the slip ring’s performance. Loose electrical connections around the slip ring should be clean and tight. Wear protective clothing and follow all the safety rules before starting work.

Conclusion

Conducting regular slip ring cleaning is essential for maintaining the peak performance of wind turbines. You'll avoid emergency shutdowns, which can delay operations, costing time and money.

Having a straightforward step-by-step cleaning process ensures that the slip ring and the surrounding components are adequately cleaned. Proper cleaning and maintenance of slip rings today can prevent bigger and more expensive problems in the future.