IEC 61868:1998 PDF

Name: IEC 61868:1998 — Mineral insulating oils - Determination of kinematic viscosity at very low temperatures
SKU: IEC 61868:1998
Price: 35 EUR
Availability: InStock

Mineral insulating oils - Determination of kinematic viscosity at very low temperatures

Название (английский):

IEC 61868:1998

Mineral insulating oils - Determination of kinematic viscosity at very low temperatures

Статус документа:: Действующий
Формат:: Электронный (PDF)
Количество страниц:: 21
Дата публикации:: 16 ноября 1998 г.
Издание:: IEC IS 61868 edition 1 version 1
ICS:: 01

Тип поставки:

Full version315 €Read online 24h10 €Read online 72h15 €

Язык документа:

ruen

Срок поставки:4 раб. дн. (перевод)

Цена:315 €

Описание (английский):

Specifies a procedure for the determination of the kinematic viscosity of mineral insulating oils, both transparent and opaque, at very low temperatures, after a cold soaking period of at least 20 h, by measuring the time for a volume of liquid to flow under gravity throught a calibrated glass capillary viscometer. Applies at all temperatures to both Newtonian and non-Newtonian liquids having viscosities of up to 20 000 mm2/s.

Abstract

Похожие стандарты

Стандарты, упомянутые в описании

Overview

IEC 61868:1998 is an International Standard developed by the International Electrotechnical Commission (IEC) that specifies a standardized method for determining the kinematic viscosity of mineral insulating oils at very low temperatures. This measurement is crucial for ensuring the reliability and performance of electrical equipment operating in cold environments.

The standard addresses both transparent and opaque mineral insulating oils, providing a method that simulates real-world conditions by including a cold soaking period of at least 20 hours before testing. Viscosity is measured by timing the flow of oil under gravity through a calibrated glass capillary viscometer, accommodating both Newtonian and non-Newtonian fluids with viscosities up to 20,000 mm²/s.

Key Topics

Scope and Application IEC 61868 applies to mineral insulating oils used as dielectric fluids in electrical equipment, especially transformers, operating at very low temperatures (down to –40 °C). The standard is particularly relevant for oils that exhibit complex, non-Newtonian behavior due to microcrystal formation after prolonged exposure to cold.

Cold Soaking Procedure The oil sample must be subjected to a cold soak period of at least 20 hours to allow microcrystalline structures to develop, which influences viscosity. This simulates conditions in electrical equipment that remains stationary in cold climates.

Measurement Principle Viscosity is determined by measuring the time it takes a fixed volume of oil to flow through a glass capillary viscometer under gravity, without inducing heat or movement that could alter the viscosity. This method ensures realistic viscosity values representative of actual oil behavior in service conditions.

Handling Newtonian and Non-Newtonian Fluids The standard recognizes that some mineral insulating oils may exhibit variable viscosity depending on shear forces, especially at low temperatures. The procedure accounts for these properties to provide reliable measurements.

Calibration and Apparatus Detailed requirements are specified for the viscousmeter calibration and related apparatus to maintain accuracy and repeatability of measurements.

Applications

Electrical Equipment Safety and Performance The viscosity of insulating oils affects cooling and dielectric properties of transformers, switchgear, and other electrical components. IEC 61868 helps validate oil suitability for use in cold climates, preventing equipment failure due to increased viscosity and reduced flow.

Quality Control in Oil Manufacturing Oil producers can use this standard to assess product quality, ensuring consistency and performance under low-temperature conditions relevant to target markets.

Research and Development Laboratories testing new insulating oil formulations benefit from this method to evaluate temperature-dependent viscosity characteristics, aiding innovation to improve cold climate performance.

Regulatory Compliance Utilities and manufacturers may refer to IEC 61868 for compliance and certification of insulating oils in regions exposed to extreme winter temperatures.

Related Standards

ISO 3104:1994 – Petroleum Products – Transparent and Opaque Liquids – Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity. IEC 61868 adapts this standard for very low temperature applications with additional requirements.

ISO 3105:1994 – Glass Capillary Viscometers for Kinematic Viscosity – Specifications and Operating Instructions. This standard complements IEC 61868 by specifying viscometer characteristics and usage.

IEC 60050 – International Electrotechnical Vocabulary (IEV). Provides standardized terminology to support consistent understanding across electrotechnical standards including terminology for viscosity and fluid properties.

IEC 60027, IEC 60417, IEC 60617 – Standards covering letter symbols, graphical symbols, and schematic symbols used in electrical technology documentation.

By adhering to IEC 61868:1998, stakeholders ensure that mineral insulating oils perform reliably in cold environments, maintaining the safety and efficiency of electrical installations. This standard is a vital reference for laboratories, manufacturers, and utilities managing insulating liquids in cold climate applications.

IEC 61868:1998 PDF

Abstract

Похожие стандарты

Overview

Key Topics

Applications

Related Standards

Технические детали

ISO 3104:1994

Petroleum products — Transparent and opaque liquids — Determination of kinematic viscosity and calculation of…

ISO 3105:1994

Glass capillary kinematic viscometers — Specifications and operating instructions

IEC 60050-161:1990/AMD2:1998

Amendment 2 - International Electrotechnical Vocabulary (IEV) - Part 161: Electromagnetic compatibility

IEC 60027-1:1992/AMD2:2005

Amendment 2 - Letter symbols to be used in electrical technology - Part 1: General

IEC 60417-2:1998/AMD2:2002

Amendment 2 - Graphical symbols for use on equipment - Part 2: Symbol originals