Table of Contents
What is the Bil?
The basic insulation level or BIL of an electrical equipment determines the principle dielectric qualities of the apparatus and is expressed for impulse tested apparatus by peak value of the 1/50 microsecond full wave withstand voltage.
What is bil in electrical?
Definition: A reference impulse (voltage) insulation strength expressed in terms of the peak value of the withstand voltage of a standard impulse voltage wave. It is used to express the ability of electrical equipment such as transformers to withstand certain levels.
What is meant by Bil of an equipment?
Insulation levels in electrical equipment are characterized by the withstand voltages used during the design tests. There are two basic classifications of insulation strength: basic insulation level (BIL) or lightning-impulse withstand voltage, and power-frequency withstand voltage (often called “hipot” voltage).
What is bil in transformer?
What is BIL and how does it apply to transformers? BIL is an abbreviation for Basic Insulation Level. Insulation levels in electrical equipment are characterized by the withstand voltages used during the impulse test.
What is bil on transformer?
What is Bil used in insulation coordination?
The minimum level is known as the Basic Insulation Level (BIL) that must be that of all of the components of a system. Insulation values above this level for the lines and equipment in the system must be so coordinated that specific protective devices operate satisfactorily below that minimum level.
What is bil for transformer?
What is the Bil of a transformer?
When power system equipment like transformers are manufactured, the winding insulation design is based on a BIL specified by the customer and is related to the nominal system operating voltage.
What is Bil in insulation?
BIL stands for basic lightning impulse insulation level although this is often shortened to basic impulse level or basic insulation level. BIL is not the same as the withstand strength of an insulation system.
What type of Bil do I need for a distribution transformer?
Pwer transformers normally use 110 kV BIL, distribution transformers are associated with 95 kV BIL. The 95 kV BIL is very common, especially on underground systems which are not exposed to lighting. If you have particular concerns, I recommend performing (or having someone perform) an insulation coordination study.
What is the difference between 110 kV and 95 kV Bil Transformers?
Normally 110 kV BIL is only used for substation equipment on 13.8 kV systems. You will have a higher probability of lightning failure on your transformer than if you had a 110 kV BIL transformer, even with arresters, because the protective margin will be smaller with 95 kV BIL.