Safety of biolubricants in electrical equipment

An IEC (International Electrotechnical Commission) product story

Edited by the Engineeringtalk editorial team Dec 6, 2005

The IEC's TC10 committee, which prepares standards for fluids used in electrotechnical applications, has decided to establish a new working group for biolubricants in electrical equipment.

At its most recent meeting held in October 2005 during the IEC's 69th General Meeting in Cape Town, South Africa, TC10, which prepares standards for fluids used in electrotechnical applications, decided to establish a new working group (WG) to focus on the use of biolubricants in electrical equipment.

The new WG (Natural esters for electrical purposes) is to prepare standards and/or specifications for unused natural esters as well as guides for maintaining such fluids in operative equipment (natural esters are derivatives of vegetable oils and constitute a new family of organic synthetic esters).

A call for experts should be sent shortly by TC 10's secretary and, at present, only the name of the convenor is known (Gary Gauger, from the USA).

TC10's chairman, Alfonso de Pablo, says the main reason for initiating standardisation activity for natural esters is to assure worldwide uniformity on the minimum acceptable values for these oils.

This harmonisation is expected to facilitate their substitution for traditional mineral oil and other fluids in some specific applications.

The creation of the WG also reflects the growing interest and need worldwide for new technologies and alternatives that offer improved safety, reliability and cost benefits in the long run.

Experts also see an increasing demand for environmentally-compatible lubricants such as natural esters, especially for areas where the possibility for contact with water, food or people is high.

Natural esters represent a valuable renewable material that can be used as petroleum and other fuels.

Their considerable aquatic biodegradability (99 per cent after 21 days) constitutes an additional benefit.

Many experts also point out that, for some applications, using natural esters offer several notable advantages over conventional mineral oils.

For example, they have much higher ignition resistance, with flash points above 300C compared to 150C for mineral oils.

This improves safety margins in the case of short-circuit currents and contributes to the also increasing interest in higher temperature rise ratings for liquid-filled transformers (IEC 60076-14 lists agricultural esters as a dielectric coolant option) [a dielectric material - which can be solid, liquid, or gaseous - is a substance that is a poor conductor of electricity but an efficient supporter of electrostatic fields].

The WG's main objectives and projects for the coming months include: proposing whether a new guidance document should be an independent standard or part of already existing standards such as IEC 61099 and IEC 61203; developing specifications/minimum requirements that unused fluids must fulfil to ensure fluids' in-service reliability and equipment; and assisting users with supervision and maintenance.

For De Pablo, having a new reference document should particularly interest distribution and power equipment standards committees, consultants, manufacturers, service companies and testing laboratories, insurance companies, environmental regulatory agencies, educators and electrical installation inspectors.