Recent content by raynh

Can any body please tell me what does (Rated short-circuit making current) stands for? E.g Rated short circuit breaking capacity is 25kA, while the Rated short circuit making capacity is 62.5kA, Regards

Thank you Slava, I went over the old forum , nothing that I am looking for, Again my question Why do we have the tertiary windings (beside the suppression of the 3rd harmonics. I appreciate any feed back Regards

Can anybody tell me please why do we use the tertiary winding in the transformers? Regards

Thanks Ruggedscot's & Davidbeach's, According to IEEE dry type Transformers are usually used for step down. However I think that the price of dry type is higher than the oil type, but you are right for the hazardous point of view. Regards

Can anybody tell me why dry type transformers are usually used for step down transformation Regards

Thanks every body, the cooling system was ONAN/ONAF/ONAF, and what confused me is that (the cooling system for the 80 &100 MVA is still the same using(ONAF), so how can the capacity of the transformer increases from 80 MVA to 110 MVA with the same cooling system, however what asekhar said makes...

Can any body explain what does it mean 60/80/110 MVA? for step up Power Transformers (60/80/110 MVA) 115/34.5kv, regards

Hi 7anoter4 Thank you for yr reply, and I fully agree with you, however my load is lighting and HVAC and no further extension expected in the building, the 80% you mentioned , is it according to any international code? or it is subjected to the designer estimate? Kind Regards

ABB CAN PRODUCE SUCH TYPE OF TRANSFORMERS

Thanks Alehman, My question was how much can I load a new transformer of 250kva according to B.S or Canadian code, can I load it till 80or 90% of the transformer rating? For both oil and dry type

Can any body please tell me what is the permissible load that can be connected to a power transformer (250KVA)for an ambient temp. which does not exceed 45deg. cen, indoor type according to the codes, the transformer is new .