Bil rating for transformer

Bil rating for transformer

BIL is an abbreviation for Basic Impulse Level. Impulse tests are dielectric tests that consist of the application of a high frequency steep wave front voltage between windings, and between windings and ground. The BIL of a transformer is a method of expressing the voltage surge that a transformer will tolerate without breakdown.

In the design of lines and equipment considering the minimum level of insulation required, it is necessary to define surge voltage in terms of its peak value and return to lower values in terms of time or duration. Although the peak voltage may be considerably higher than normal voltage, the stress in the insulation may exist for only a very short period of time.

Bil rating for transformer

What is the basic impulse level (BIL) rating of the insulation system on Square D/Schneider Electric's Low Voltage Dry Type Distribution Transformers?

Whenever a over voltage surge appears in the system, it is discharged through surge protecting devices before the equipments of the system gets damaged. Hence, the insulation of such equipment must be designed to withstand a certain minimum voltage before the over voltage surge gets discharged through surge protecting protection devices. Hence, operating voltage level of surge protecting devices must be lower than the said minimum voltage withstanding level of the equipment. This minimum voltage rating is defined as BIL or basic insulation level of electrical equipment.


The complete 200 kV BIL deadbreak connector system includes T-bodies, insulating plugs, junctions, caps, reducing tap plugs and transformer bushings. Combining the 200 kV BIL deadbreak system with Cooper Power series 200 kV nameplate rated transformer means no longer sacrificing system protection due to limited component ratings.

Sonal Transformer (Capacity 750 VA, Bil Rating 34.5 Kv) Control Transformer (Phase 1)

Electricals or its umbrella term Electrical equipment are used by professionals to fix or install wires and electrical fixtures. Electricals are widely used by almost every industry without whom industrial output would seldom be imagined. In our country, with booming industrialization and urbanization it’s pertinent to have this necessary feature for sustenance. Whether you’re moving to your new home or rewiring your workplace, reliable electrical equipment is a necessity that cannot be overlooked.

What is the Transformer BIL (Basic InsulationLevel)?

We offer a wide variety of 600 volt class indoor voltage transformers for metering. All of our voltage transformers are encapsulated in polyurethane resin and are UL recognized. Our three phase voltage transformers are designed for line to line or line to ground connection.

General Purpose Low Voltage (600 volts)

Olsun Electrics General Purpose Ventilated Single (GS) phase and Three (GT) phase transformers are the high quality constructed and DOE efficient units the industry has come to expect from Olsun for supplying power to electrical distribution systems.

Dry-type transformers

This document does not constitute part of the Energy Efficiency Act (Act) or its associated regulations.  This document is an administrative document that is intended to facilitate compliance by the regulated party with the Act and its associated regulations.  This document is not intended to provide legal advice regarding the interpretation of the Act or its associated regulations. If a regulated party has questions about their legal obligations or responsibilities under the Act or its associated regulations, they should seek the advice of legal counsel.