sending the design calculations that met our requirement. He also agreed to test the transformer for all routine tests, Short Circuit, Impulse and temperature rise tests to prove his design beyond doubt. This manufacturer also offered the fastest delivery period. The transformer has the following main features. Sr. Description Unit Offer No. 1 Service Indoor HV winding kVA 1500 kVA at LV 690 volts KVA Rating 2 kVA Varies as per the Selected LV winding Voltage tap HV winding kV 11000 3 Rated No load voltage kV Varies as per the Selected winding Voltage tap 4 Rated Frequency Hz 50 5 Number of Phases 3 Phase HV winding Delta/Star Connections LV winding Delta/Star - Series/Parallel 6 OLTC or Off Off Load circuit Tap Tap switch Changer 7 Type of Cooling ONAN Top Oil ºC 55 Temperature rise above 8 50ºC Winding ºC 65 Insulation Level i) Separate source HV winding kV rms 28/5 kV rms for one minute power frequency kV rms winding voltage withstand 9 HV winding kV rms 2x Rated voltage and ii) Induced over frequency for one minute voltage withstand winding kV rms iii) Impulse voltage kVp 75 kVp/nil HV winding withstand At full load 98.94 Efficiency at 75 ºC at 10 At ¾ full load 98.90 unity power factor At ½ full load 98.68
sending the design calculations that met our requirement. He also agreed to test the transformer for all routine tests, Short Circuit, Impulse and temperature rise tests to prove his design beyond doubt. This manufacturer also offered the fastest delivery period. The transformer has the following main features. Sr. No. Description Unit Offer 1 Service Indoor 2 KVA Rating HV winding kVA 1500 kVA at LV 690 volts LV winding kVA Varies as per the Selected Voltage tap 3 Rated No load voltage HV winding kV 11000 winding kV Varies as per the Selected Voltage tap 4 Rated Frequency Hz 50 5 Number of Phases 3 Phase 6 Connections HV winding Delta/Star LV winding Delta/Star - Series/Parallel OLTC or Off circuit Tap switch Off Load Tap Changer 7 Type of Cooling ONAN 8 Temperature rise above 50ºC Top Oil ºC 55 Winding ºC 65 9 Insulation Level i) Separate source power frequency voltage withstand HV winding kV rms 28/5 kV rms for one minute winding kV rms ii) Induced over voltage withstand HV winding kV rms 2x Rated voltage and frequency for one minute winding kV rms iii) Impulse voltage withstand HV winding kVp 75 kVp/nil 10 Efficiency at 75 ºC at unity power factor At full load 98.94 At ¾ full load 98.90 At ½ full load 98.68