Product Details: Tapping: + 5% to -15% in steps of 1.25% or as per customers requirement. Range of Transformer : Upto 3500 KVA Frequency: 50 ~ 60 Hz On-load tap changer (OLTC) is used with higher capacity transformers where HT side voltage variation is frequent and a nearly constant LT voltage is required. OLTC is coupled with the transformer itself. Multiple tapings from HV winding are brought to the OLTC chamber and connected to fixed contacts. Moving contacts rotates with the help of rotating mechanism usually a Geneva mechanism having a spindle. The spindle can be rotated manually as well as electrically with a motor. The motor is connected in such a way that it can rotate in both the directions such as to rotate the OLTC moving contacts clockwise and anti-clockwise. Two push buttons are fitted on the LCP (low control panel) to rotate the motor and hence the OLTC contacts. This movement of contacts thus controls the output LV voltage of the transformer. So rotating of the OLTC contacts with the spindle or push button in this way is the manual process. In case this process of rotating the OLTC contacts and hence controlling the LV side voltage is to be done automatically then an RTCC (remote tap changer controller) is installed with the transformer hot panel. The RTCC panel which has sensors which sense the output voltage and accordingly sends the signal to LCP and LCP in turns rotates the motor as per signal received from the RTCC. Other Details: Vector Group: Unless or otherwise specified, the transformers will be connected as per Vector Group reference Dyn 11 in accordance with International practice. Core: The core used is the best quality cold rolled grain oriented and laser processed silicon steel sheet. They provide low iron loss, low noise, and compact size and have the best performance for high-efficiency transformers. Windings: We use high-quality conductor of copper aluminum in our products. Round or rectangular copper/aluminum wires ribbed with thermally upgraded insulting paper are applied in oil immersed transformers. The winding has a compact size, excellent heat transmission, low load loss, highlighting impulse resistivity and outstanding anti-short- circuit strength. Insulation: Our oil-immersed transformers are insulated by electrical grade insulated press board and thermally upgrade insulating Kraft paper. Oil: Dehydrated EHV-Grade transformers oil as per IS 355 (1993) with latest amendments is used for proper insulation and cooling after testing for all the parameters viz a viz resistivity, tan delta, BDV, neutralization, flash point etc. Bushings: HV/LV Bushings: The quality porcelain bushings are used on the high voltage terminals/low voltage terminals. Optional bushing wells, inserts, and elbows are available upon request. High voltage cables are inserted directly and show no live parts outside. Accessories: The accessories include an oil filling hole, oil drain valve, safety valve, standard thermometer, oil level gauge, skid wheel, jacking pad, breather, earthing terminal Optional Accessories: Buchholz relay, cooling fan, HV LV cable box, cable duct, bus bar duct, dial-type thermometer, oil level gauge, on-load type tap changer, protective fuse and lightening arresters are available upon customer’s request at extra cost. OLTC Transformers are used in: Chemical plant, Bottling plant. Paper mills, Sugar Mills, Rolling Mills, Steel Mills. Industries which rely heavily on automation, where electronic cards, PLC, and VFDs are used in operations and actuation.