Standard specifications of a Power Transformer :

 ●●● Standard specifications of a Power Transformer :

• Number of phases: single or polyphase  

• Frequency : 50Hz 

• KVA Rating : generally rated in MVA (like 200 MVA) 

• Rated voltages for each winding: 440KV/220KV, 220KV/66KV(greater than 33KV)  

• Connection symbol : star/delta 

• Requirements of on-load / off-load tap changers  

• Impedance voltage at rated current  

• Indoor or outdoor type 

• Type of cooling : ONAN,ONAF,OFAF,OFWF 

• Temperature rises and ambient temperature conditions including altitude and in case of water cooling, chemical analysis of water.  

• Number of cooling banks, spare capacity and cooling pumps & fans. 

• Highest system voltage for each winding  

• Method of system earthing for each winding Insulation levels  

• Over fluxing conditions  

• Details of auxiliary supply voltage (for fans, pumps, OLTC, motor alarm, control).  

• Controls of tap changers  

• Short circuit levels of the system  

• Vacuum and pressure withstanding values of the transformer tank  

• Noise level requirement  

• Number of rails and rail gauge for movement along shorter and longer axes  

• Fittings required with their vivid description