TESTING      TEST and MAINTENANCE UNIT is the newest service of Özdil Co. established in 1997. Whit this unit, wa aim to perform the commissioning tests of the new installations right before they put into the service. TEST and MAINTENANCE UNIT has expertand very well trained staff. The test devices are big investments. Özdil Co. has established one of the best TEST and MAINTENANCE UNIT in 1997 by tusting its experience in the energy Sector over 25 years. Since then this unit has successfully accomplished these works 1. The primary and secondary field tests of the 30 substations before commissioning, which most of them have been installed by Özdil Co. 2. The tests of total 320 km lenght fiber optic cable (OPGW) connections of 380 kV and 154 kV transmissionslines. This group is also specialized for electrical project of EHV and HV substations. In this context, we hane prepared secondary system designs and drawings 154/33,6 kV turnkey substations of Bahçeşehir, Taşoluk and Saruhanlı. We Proudly present our TEST and MAINTENANCE UNIT to the service of the eligible Firms of Energy sector. In Özdil Group, studies to have this special group as an individual company are being continued.