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By I.A.R. Gray(Senior Consultant-(MSAChem I No 51594)
Oilwatch Transformer Service

INTRODUCTION
Load tap changers (OLTCs) are a crucial element of utility networks, as they must operate in a precise fashion in order to maintain a constant voltage output. This must be achieved regardless of variation on input or load. OLTC’s have been a weak link in many networks as they deteriorate over time due to mechanical problems or contact wear from repeated operation. Erosion of the contacts over time is expected due to the nature of their function. Coking of the contacts causes overheating, which can cause thermal runaway. Regular maintenance is necessary to ensure continued proper functioning
Oil testing has long been recognized as an important tool for detecting incipient faults in the main tanks of transformers and is being applied to load tap changers. Download to read more

OLTC-analysis-IARGray-July 2021-rev1 (35 downloads)