Grease products recommended by OEM for conventional 11kV switchgears are generally trusted. Some disadvantages might however exist among them or their supply could be insufficient and lead to use of non-OEM-recommended grease. This paper reports analysis methods to evaluate both types of grease that were recently used in the switchgears at local electrical distribution stations owned by Tenaga Nasional Berhad. Hardened, greenish and severely irritating greases probably caused by incompatible compounding, electrochemical reaction, and hazardous components, respectively, were among common problems faced by workers. Eight physical tests and four chemical tests were conducted on 10 grease samples using thermogravimetry, switchgear rig, gas chromatography and infrared spectroscopy besides other equipment and standard methods. Grease stability, oil bleeding, flammability of grease droplet and dropping point were among the characteristics determined in the analyses. The results reveal copper corrosion, chemical change, instable and inconsistent grease, and toxics in grease, which surprisingly included the OEM-recommended one. ABSTRAK: Produk gris yang disyorkan oleh Pengeluar Peralatan Asal (OEM) bagi gear-suis konvensional 11 kV secara umumnya dipercayai ramai. Kemungkinan terdapat kekurangan pada produk-produk tersebut ataupun bekalan gris mereka yang tidak mencukupi telah mendorong kepada penggunaan gris yang tidak disyorkan oleh OEM. Kaedah analisis kajian ini melaporkan tentang kedua-dua jenis gris yang kebelakangan ini digunakan oleh Tenaga Nasional Berhad pada gear-suis di stesen pencawang elektrik. Gris mengeras, berlumut dan menjengkelkan mungkin disebabkan oleh sebatian bahan yang tidak sesuai, tindak balas elektrokimia dan komponen yang tidak selamat, masing-masing adalah antara masalah yang dihadapi oleh para pekerja. Lapan ujian fizikal dan empat ujian kimia telah dijalankan pada 10 sampel gris menggunakan termogravimetri, pemakai gear-suis, kromatografi gas dan spektroskopi inframerah selain alatan lain dan kaedah-kaedah piawai. Antara ciri-ciri yang dikaji dalam analisis ini adalah kestabilan gris, sifat lelehan minyak, sifat mudah terbakar titisan gris dan takat rendah gris. Hasil kajian mendapati gris ini menyebabkan tembaga terhakis, sifat kimia berubah, sifat gris yang tidak stabil dan mudah berubah, dan juga beracun memberi kejutan kerana pihak OEM tetap mengesyorkan gris jenis ini.

The disposal of waste oils, particularly waste engine oil (WEO) and waste turbine oil (WTO), presents serious economic and environmental issues due to their high contamination and degradation levels, which reduce the efficiency of direct reuse or conventional recycling. This study investigates a practical approach for upcycling WTO and WEO into high-performance lubricating grease, providing a sustainable substitute for petroleum-based lubricants. The study includes five essential stages: waste oil collection, pre-treatment, characterization, grease formulation, and performance assessment. Following treatment, the viscosity, elemental content, and moisture levels of the oils complied with Department of Environment (DOE) and ASTM D5185 standards, confirming their viability as base oils. The formulated greases achieved NLGI grades of 2–3, oil bleed percentages within a ± 15%, and oil separation below 4%. They also exhibited low coefficients of friction (0.062–0.133) and wear scar diameters ranging from 415.65 to 866 μm. These results confirm that treated WTO and WEO can be converted into greases with performance comparable to conventional products, supporting reduced dependence on virgin base oils. The formulations were assessed under relevant ASTM and NLGI standards. Future work may explore additives or scale-up approaches to enhance long-term performance and market readiness.