Exam Question

(a) With reference to large electrical transtormers on board ships:

(i) state where these transformers may be used (2)

(ii) State a typical efficiency range for a transtormer (2)

(iii) State the protective devices that are fitted (2)

(iv) Describe the maintenance requirements (2)

(b) What are the losses in transformers? Mention the various factors which affect these losses. In a 25 KVA, 3300/233 V, single phase transformer, the iron and full-load Cu. losses are respectively 350 and 400 watts. Calculate the efficiency at half-full load, 0.8 power factor. (8)