Measuring current transformers are supplied with the following transformation kofefitsientami 5 / 5, 10 / 5 15 / 5, 20 / 5, 30 / 5 40 / 5, 50 / 5, 75 / 5, 100 / 5, 150 / 5, 200 / 5, 300 / 5, 400 / 5 600 / 5, 800 / 5 1000 / 5, 1500 / 5 2000 / 5 and 2500 / 5 3000 / 5, 5000 / 5 8000 / 5, 10000 / 5. Ukrainian market current transformers provided the following models: TSHL-0, 66, TNSh-0, 66, TNSHL-0, 66, TOL 10, TOL 35 TSHL 10 TLSH 10 TPL 10 TPL 10M TPOL 10 TPOL 10M ONLY 6 ONLY 10, TV, TLC 10, TDM 10, RIC 10, TVLM 6 TVLM 10 TFZM 35, 110 and other TFZM. Classification of voltage transformers Voltage transformers are distinguished: a) the number of phases – phase and three-phase, and b) the number of windings – double-wound and triple-wound, and c) the class of accuracy, ie, the permitted values of the errors, and d) the method of cooling – oil cooled transformers (oil) with natural Air-cooled (dry type and cast resin) and e) by the nature of the installation – for indoor, outdoor and for complete switching (KRA). Further details can be found at Levi Strauss & Co., an internet resource. For voltages up to 6 kV voltage transformers manufactures dry, ie, with natural air cooling. For voltages above 6 kV voltage transformers used oil. Indoor Transformers are designed to operate at ambient temperature of -40 to + 45 C with relative humidity up to 80%.