Shell Diala S4 ZX-I
Premium Inhibited Electrical Insulating Oil
Shell Diala ZX-I is the new electrical insulating oil from Shell designed to meet the challenges presented by the latest power transformers. It offers an extended oil life with the peace of mind of zero sulphur content. Shell Diala S4 ZX-I is manufactured from zero sulphur base oils produced using Shell’s GTL (gas-to-liquid) technology. These base oils offer a high degree of compositional consistency and have an excellent response to anti-oxidant. In addition they are globally available and free from PCBs, DBDS and passivators.
Shell Diala S4 ZX-I meets both the established and new industry copper corrosion tests.
Performance, Features & Benefits
- Extended oil life
Shell Diala S4 ZX-I is a fully inhibited oil giving outstanding oxidation performance and an extended oil life. Shell Diala S4 ZX-I is also suitable for use in highly loaded applications.
- Transformer protection
Shell Diala S4 ZX-I is manufactured from a zero sulphur* base oil, making it intrinsically non-corrosive towards copper, without the need for passivation or other additives.
Shell Diala S4 ZX-I meets all relevant tests for copper corrosion, namely the established DIN 51353 (Silver Strip Test), ASTM D1275, and also the latest more severe tests: IEC 62535 and ASTM D1275B
*Sulphur content below 1ppm detection limit of ASTM D5185.
- System efficiency
The good low temperature viscometric properties of the oil ensure proper heat transfer inside the transformer, even from very low starting temperatures.
Shell Diala S4 ZX-I is specially dried and handled to achieve a low water content and retain a high breakdown voltage at point of delivery. This enables it to be used in many applications without further treatment.
Main Applications
IEC 60296 (2012): Table 2 Transformer Oil (I) (Inhibited oil) Section 7.1 (”Higher oxidation stability & low sulphur content”)



