General Specification

This specification describes the technical layout, the performance and the workmanship of a transformer oil regeneration system, Type EOK-TORS.

Introduction

The growing consumption of electrical energy continuously demands higher degrees of durability and safety of operation of the generating, transforming, switching and conduction electrical devices. Transformer oil is in an environment that leads to a degradation in its desired properties. Over time, even in a proactive maintenance program, transformer oil loses its insulating properties and its cooling properties. The rating requirements and drive to tighter tolerances of modern transformers and electrical apparatus results in greater electrical stress in insulating material and fluids. To handle these stresses, oils are required to have better dielectric strength, and lower residual water content must be maintained to reduce the speed of oil aging. The timeous and proper treatment of these insulating fluids will result in the improvement of the properties of the entire insulating system of power transformers and will extend the effective lifetime of the asset.

The principal functions of the insulating fluid are to serve as a dielectric material and an effective coolant. To perform these functions, the insulating fluid must possess specific qualities at the time of initial impregnation of the transformer core and filling of the tank at the manufacturer’s factory and which must be maintained at the same level in field operation if optimum performance is to be guaranteed. Typically, these qualities are well-defined by international and national standards authorities e.g. IEC 296, BS 148, SABS 555, etc.

Transformer oils deteriorate with time and the decay begins the moment the transformer is brought into service. High temperatures, the presence of oxygen and water, the catalytic action of the materials within the transformer, all combine to result in oxidation and cracking of the transformer oil. The by-products of this oxidative process are acidic and the long-term effect of exposure to these products results in an ever-increasing rate of deterioration of the transformer and its oil. The resulting sludge build-up reduces the cooling effects of the oil driving the whole decay mechanism at an increasingly accelerated rate. Although there is no specific acidity level at which action should be taken to treat the oil (generally this action level is determined by the asset value), historical data shows that the acid number becomes exponential around the 0.2 mg KOH/g oil level.

Our EOK-TORS and TORS are used not only to stop the deterioration/ aging process of the oil, but to completely reverse the process. After the regeneration the oil is comparable with new oil, in many cases the oil quality is even better.

Technical Data Sheet

Expected Performance Data
Parameter Measured	Water content	< 5	ppm
after 3 passes	Gas content	< 0.3	vol%
	Breakdown voltage	>75	kV/2.5mm
	Acidity	<0.01	mg KOH/g oil
	Tan Delta	<0.001	at 90°C
	IFT	>45	dynes/cm
	Oxidization - acidity	<0.2	mg KOH/g oil

Regenerating your transformer oil with the EOK-TORS® Series provides you with,

• Economic advantages – regenerated oil is 20 to 50% cheaper than buying new.
• Life extension with efficiency boost – transformer oil can be regenerated more than six times without efficiency loss.
• Control of transformer oil as strategic asset – use of EOK-TORS® makes you independent from oil suppliers.
• Removal of corrosive sulfur – Dibenzyl Disulfide, one of the main causes for transformer failures, gets removed expanding your equipment’s lifespan.
• No downtime due to regenerating – EOK-TORS® units can be operated on energized transformers as effectively as on un-energized transformers.

Hering Systems are remarkable for their efficient and robust design, as well as their ease of operation and maintenance. We install only high quality components from Germany, respected West European brand manufacturers. Our systems are designed for long lifetime, reliability and effective operation. Each plant is custom-made and delivered with all required aggregates to leave nothing to be desired. Together, we will develop the perfect solution for you and your company. We are looking forward to serving you!