In substation operation and maintenance records, situations like this often occur: the online monitoring data of oil chromatography for a certain main transformer shows abnormal fluctuations at night, but manual sampling and re-inspection reveal no corresponding gas component exceeding the standard. Such phenomena are often related to the monitoring system's adaptability to the working environment, calibration cycle, or data storage mechanism. For procurement personnel, understanding the technical root causes of these field problems is more helpful for selecting equipment that matches the working conditions than simply comparing quotations.
Question 1: Periodic jumps in monitoring data are related to which parameter settings?
The analysis cycle of the online monitoring system can be set arbitrarily within a minimum of 1 hour. If the analysis cycle is too short and the transformer load fluctuates greatly, the dissolved gases in the oil have not yet fully equilibrated, and the detection results are prone to fluctuation. At the same time, for equipment with a calibration cycle longer than 2 years, if there is no self-calibration mechanism between two calibrations, baseline drift may also be misread as changes in gas concentration. During procurement, it should be confirmed whether the analysis cycle supports flexible adjustment according to working conditions, and whether the calibration method affects long-term data continuity.
Question 2: How can outdoor installation units ensure stability in areas with large temperature differences?
The operating ambient temperature range of the transformer oil chromatography online monitoring system is usually -40°C to +70°C, and the monitored transformer oil temperature range is 15°C to 80°C. Outdoor installation components need to meet IP56 protection rating, while indoor main station units are IP51. Procurement personnel need to verify whether the equipment clearly distinguishes the protection requirements for indoor and outdoor components, and whether the storage and transportation extreme ambient temperatures cover the extreme climate of the project location. Insufficient enclosure protection will lead to the intrusion of moisture or dust, affecting the service life of the chromatographic column and detector.
Question 3: How do the service lives of the chromatographic column and detector affect later replacement costs?
Chromatographic columns using regular self-activation technology can have a service life of more than 8 years; the detector life is usually more than eight years. These two parameters directly relate to the maintenance expenditure over the entire life cycle of the equipment. During procurement, suppliers should be required to clarify the trigger conditions and effect verification methods of the self-activation technology, rather than focusing only on the initial purchase price. A data storage period of 20 years means that historical trend analysis has a sufficient data foundation, but it is necessary to confirm whether the storage medium supports local export and remote backup.
Question 4: What on-site verification points are there in the oil-gas separation and oil intake stages?
The system needs to realize automatic quantitative cyclic cleaning, oil intake, oil-gas separation, sample analysis, data processing, and real-time alarms. Procurement personnel can focus on verifying whether the oil intake pipeline is compatible with the on-site transformer interface, whether the oil-gas separation device is sensitive to oil temperature changes, and whether the cleaning process will cause cross-contamination. The engineering design of these stages directly affects the consistency between monitoring data and laboratory sampling results.
