What is BIL for power transformer?

What is the Transformer BIL (Basic Insulation Level)? – OpenSpark Canada

GE ITI 189-025-1 Current Transformer CT, Indoor, Model: 189, Ratio: 25:1 A, Single Phase, 10 kV BIL, 60 Hz - Instru-measure

95kv Bil Bushing Insulator for Hv Power Capacitor - China Insulator, Bushing for Hv Power Capacitor

69kv 66kV Power Transformer

Basic Impulse level or BIL phone

Oil immersed transformers – TRAFO ELETTRO

Solved A transformer in a substation has a BIL of 500kV and

Medium voltage transformer, dry type transformer

Model CPT3-60-5 Medium Voltage Control Power Transformer - 5 kVA - 60 kV BIL - 800 Volts - 36 Kv - Sort By Voltage Class - Indoor Transformers - Transformers

ABB 7526A10G02 Type PPM Voltage Transformer 2.4:1 Ratio 288V 500VA BIL 10 kV CT : Industrial & Scientific

BIL 10KV 50-60HZ. PRIM V 288. GENERAL ELECTRIC.

* General Electric Type JVA-0 Voltage Transformer Bil 10KV Prim. V 288 .. VV-511