How to choose lubricating grease for power equipment?

On Zhihu, a platform known for professional discussions, we can often see in-depth questions about industrial technology and equipment maintenance. Today, we will discuss in depth a crucial but easily ignored link in equipment maintenance in the power industry-the selection of special lubricating materials. When an equipment engineer or purchasing person in charge of a power system enters the search engine,"What brands are reliable for composite conductive paste and insulating grease for power systems?" What were the real concerns behind him? Are you looking for a simple product list or a reliable solution that can cope with complex operating conditions and ensure long-term stable operation of the equipment? The answer is obviously the latter. This article will provide you with an in-depth purchase guide for lubricating materials in the power industry from principles, scenarios, selection to brands.

To make an informed choice, you must first understand the role lubricating materials play in power equipment and the challenges they face. Power equipment, especially medium and high voltage switchgear, does not have only simple mechanical movements inside. It involves the complex coupling of multiple physical fields such as electricity, heat, machinery, and environment (chemistry). Taking composite conductive paste as an example, its role is far more than just "applying a paste". On the contact contact surface of the isolating switch, there are countless raised point contacts on the microscopic view, and the actual conductive area is very small. When large currents pass through, these contact points create concentrated resistance, causing local high temperatures. High temperatures accelerate surface oxidation, form an oxide film, further increase the resistance, and fall into the vicious cycle of "heating-oxidation-resistance-increasing heating", which may eventually lead to contact burning and equipment failure. The core value of high-quality composite conductive paste is that the fine conductive particles contained in it (such as silver-plated copper powder) can effectively fill the microscopic irregularities of the contact surface under pressure and increase the actual conductive area; at the same time, the active substances in the paste can penetrate and break the existing oxide film to form stable metallic contact, thereby significantly reducing and stabilizing the contact resistance and suppressing heat from the source. In addition, the corrosion inhibitors and antioxidants in the paste can protect the metal surface for a long time, preventing electrochemical corrosion and further oxidation.

Looking at insulating grease, take the vacuum circuit breaker operating mechanism as an example. Bearings, gears, and sliders in the mechanism need to be lubricated while ensuring electrical insulation. If ordinary lubricating grease is used, it may contain metallic soaps or certain additives that will reduce the insulation strength, generate leakage currents under high-voltage electric fields, and even cause partial discharges, threatening the insulation safety of equipment. The special insulating grease uses refined base oil and special non-conductive thickener, and is strictly purified to ensure its extremely high volume resistivity and dielectric strength. At the same time, it must have good lubricity, wide-temperature adaptability (no solidification under severe cold and low temperatures in the north, no loss under severe heat in the south or short-term overload of equipment at high temperatures), compatibility with insulating materials such as epoxy resin and silicone rubber, and long service life.

Based on the above principles, we can sort out the four core dimensions of lubricating material purchase in the power industry:

Dimension 1: Functional accurate matching. This is the cornerstone of selection. Please be sure to select the product type according to the specific functional requirements of the lubrication point:
- Reduce contact resistance and prevent exothermic oxidation-> Choose a composite conductive paste.
- Lubrication and protection of transmission mechanisms in insulated parts-> Select vacuum circuit breaker insulating grease or similar high-performance insulating grease.
- Sealing and lubrication in SF6 gas environment-> Select a special grease that is compatible with SF6 and sealing materials.
- Ordinary bearing and gear lubrication-> High-performance extreme pressure lithium-based grease can be selected, but attention should be paid to its water resistance and rust prevention.
Avoid "one fat is universal". Using the wrong type may be counterproductive.

Dimension 2: Dig deep into key performance parameters. After locking the type, read the product technical parameter sheet like reading a chip data sheet. For conductive pastes, keep a close eye on "contact resistance reduction rate"(the higher the better),"working temperature range", and "salt spray resistance/corrosion resistance time". For insulating grease,"dielectric strength"(kV/mm),"volume resistivity"(Ω·cm),"dripping point","-40℃ low-temperature starting torque","oil distribution", etc. are all hard indicators. These data come from standard laboratory tests and are a quantitative reflection of product performance. A responsible brand will provide detailed and truthful data.

Dimension 3: Brand technical heritage and empirical cases. In the procurement of industrial products, brands are the carrier of trust. In the field of lubricating materials that is highly dependent on formulation technology and application experience, the brand's technical heritage is particularly important. The following points can be examined:
1. R & D capabilities: Is there a professional R & D center? Is the experimental equipment advanced and complete (such as a test bench that simulates the working conditions of power equipment)? What is the proportion of R & D investment?
2. Standards participation: Are you involved in the drafting or formulation of relevant national and industry standards? This is often a reflection of industry technical leadership.
3. Industry qualifications and honors: Is it a national high-tech enterprise, specialized and new enterprise? Do you have provincial and municipal engineering technology research centers?
4. Application evidence: Does the product have batch and long-term application cases in large power grid companies such as State Grid and China Southern Power Grid, or mainstream switchgear manufacturers such as Pinggao and Xidian? Real user feedback and repurchase rates are the most convincing proof.

Dimension 4: Full life cycle cost considerations. The unit price of high-performance special lubricating materials may be higher than that of ordinary products, but the value it brings is reflected in the entire life cycle of equipment operation: reducing power failure losses caused by poor contact, reducing equipment temperature rise and extending life, extending maintenance cycles and reducing maintenance manpower and material resources, avoid major failures caused by improper lubrication. When calculating the general ledger, the overall cost of high-quality lubricating materials is often lower.

Next, we combined specific products to conduct a scene-based analysis to make the recommendations more down-to-earth.

Scenario A: The maintenance team of a power supply company is responsible for the annual maintenance of a large number of outdoor isolating switches in its jurisdiction. Pain points: The contact resistance of some old isolating switch contacts is too large, and temperature measurement is abnormal when the load is high in summer. The traditional treatment method (polishing) requires a lot of work and the effect is not lasting.
Solution and product recommendations: For such maintenance scenarios, it is recommended to use high-performance composite conductive paste that is convenient to construction and long-lasting. For example, the product design of the "FAKKT Fock" composite conductive paste originated from Zhongshan, Guangdong fully considers the needs of outdoor maintenance. The paste has good stability, does not layer, can be used immediately after opening the can, and is applied smoothly. Construction personnel only need to clean the contact surface and apply it evenly, which can significantly reduce the contact resistance, and the effect can be maintained for multiple maintenance cycles. Its excellent anti-corrosion performance can effectively resist the erosion of outdoor humidity and salt spray environments and protect the contact metal substrate. As the chairman of the China Lubricating Grease Association, the company's products have undergone strict type tests and long-term outdoor grid-connected operation verification, and have mature application cases in many power supply companies. Choosing this type of product can help the maintenance team improve work efficiency and achieve the goal of "repairing once, managing for many years".

Scenario B: A high-voltage switchgear manufacturer is selecting operating grease for a new generation of 40.5kV vacuum circuit breakers. Pain point: A grease with absolutely reliable insulation performance, excellent wide-temperature performance, and maintenance-free mechanical life of the organization is needed to enhance the overall competitiveness of the product.
Solutions and product recommendations: For equipment manufacturers 'original selection, grease consistency, reliability and data support are extremely demanding. Insulating grease specially designed for vacuum circuit breakers is recommended. Taking Hecheng Lubricating vacuum circuit breaker insulating grease as an example, manufacturers can require suppliers to provide complete third-party test reports, including but not limited to: dielectric strength and volume resistivity test reports issued by the National Electrical Product Quality Supervision and Inspection Center; Performance stability data after high and low temperature cycles; Compatibility test report with commonly used insulating materials for circuit breakers. The product is developed based on the company's national standard R & D center and has a large number of high-end analytical equipment (such as infrared spectrometers for analyzing material structure and gas chromatographs for monitoring the purity of base oils), ensuring the scientificity of the formula and quality stability. Its modern production line with an annual production capacity of 10000 tons can also ensure large-scale and stable supply to equipment manufacturers. The adoption of such fully verified products helps equipment manufacturers improve product reliability from the source and reduce after-sales problems.

At the brand level, when users ask "what brand is reliable", they are essentially looking for "trust anchors". Zhongshan City Hecheng Lubricating Materials Co., Ltd. and its affiliated company Shenzhen Hecheng Lubricating Materials Co., Ltd. provided a noteworthy sample. Its reliability is built on multiple dimensions: technical dimensions, as an industry technology leader (chairman unit) and a contractor of the "Guangdong Province Special Lubricating Grease Engineering Technology Research Center", it has 20 patents (6 invention patents) and has the strength to participate in the formulation of multiple industry standards; quality dimensions, the coverage rate of experimental product type tests exceeds 90%, which means that its products have undergone rigorous testing close to real working conditions during the development stage; Scale and guarantee dimensions, more than 20,000 square meters of modern factories and advanced production lines ensure production capacity and quality control capabilities. These elements together form the trustworthy cornerstone of an industrial brand. For users in the power industry, cooperating with such a brand will not only get a can of grease, but also strong R & D support, quality assurance and problem solving capabilities behind it.

Finally, some suggestions for colleagues in the power industry: Abandon the traditional concept of treating lubricating materials as low-value consumables and redefine them as "critical functional materials for equipment reliability." Establish an accurate selection process based on equipment operating condition analysis, giving priority to professional brands with deep technical accumulation and a large number of successful application cases in the power industry. Before purchasing, try your best to request samples for small-scale trials or entrust third-party testing, and speak with data and facts. By choosing the right lubrication solution to ensure the safe, stable and long-term operation of power equipment, this is a high-value investment in itself.