CERTIFICATE OF COMPETENCY IN POWER DISTRIBUTION (CCPD) Term-End Examination June, 2011 OEE-002 : POWER DISTRIBUTION SYSTEM - BASICS

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1 No. of Printed Pages : 11 OEE-002 O O O CERTIFICATE OF COMPETENCY IN POWER DISTRIBUTION (CCPD) Term-End Examination June, 2011 OEE-002 : POWER DISTRIBUTION SYSTEM - BASICS Time : 3 hours Maximum Marks : 70 Note : This paper has two sections, Section-A and Section-B. Both the sections are compulsory. Remarks have been mentioned in the section along with marks. SECTION - A 1. Fill in the blanks. Choose correct answer from the choices given below : 15x1=15 (distribution transformer, Aerial Bunched cables, cross loops, substation, steady voltage, Instrument transformer, Undersized, phase separation, Breakdown test, equilizer pipe, lower dielectric losses, increase, circuit breaker, technical losses, phase) (a) Secondary circuits at service voltage carry energy from along the street. (b) is a meeting point between the transmission grid and feeder system. OEE P.T.O.

2 (c) A network provides multiple paths and flexibility. (d) The main objective of power distribution organisation is to provide electricity at (e) To avoid theft of LT lines usually are used to supply power of LT to consumer. (f) Advantage of XLPE insulation is to have (g) Reliability of supply in number of transformers. with increase (h) The pipe connecting the conservator and explosion vent is known as (i) test is ensure electric strength. (j) For preventing loose LT lines is used. (k) is a switching device to make/ interrupt the load current. (1) is used for supplying the voltage circuit of indicating Instruments. (m) Loss in service cables is due to cables. (n) Improvement of sub - transmission system is to bring down (o) In case of CT's special caution is needed to ensure correct association. OEE-002 2

3 2. Write true ( ) or false ( x ) for the statements given below : 1x10=10 ON O O (a) In single phase, two wire system both the wire are connected to phase. ) (b) Transmission grid is used to carry bulk power from load centre to generation plant. ) (c) Feeders are the electricity lines closest to the consumers. (d) HT distribution has poorer voltage profile. ( ) (e) 0 and M issues properly documented manuals for every substation equipment. ( ) (f) Overloading of the transformer is avoided. (g) The criteria used for selection of transformer is current transients. ) (h) Line inspector checks the earth connections. ) (i) Isolators are mechanical switching device. ( ) (j) Power cables are used for 415 V lines to carry load current. ) OEE P.T.O.

4 3. Match the following given in Column-B : Column-A (i) Shunt capacitors (a) (ii) Transmission voltage (b) (iii) Extra high voltage (c) Column-A with 5x1=5 Column-B 11 kv to 440 kv Connected to secondary side of 33/11 kv power transformer above 33 kv (iv) XLPE cables (d) (v) Heat non-shrinkable (e) (f) for low dielectric losses for low losses outdoor XLPE OEE-002 4

5 SECTION - B Attempt any eight (8) questions : 8x5=40 1. Give the classification of voltage (or voltage levels) at different segments in the power system. 2. What are the advantages of High voltage distribution system? 3. What are the results of 0 and M activities? 4. Explain the three possible ways of cable laying. 5. What are the 3 most common type of faults in distribution system? 6. Explain in brief about different types of tests performed on transformers. 7. Analyse the reasons for transformer failure. 8. Distinguish between current and voltage transformer. 9. What are the protection system used for transformer? 10. What factors contribute to T and D losses? 11. Describe the various measures that can be taken for reducing commercial losses. 12. Discuss the legal provisions of Electricity Act OEE P.T.O.

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7 (c) -tifqqr h 3ifq-w wd t I 4RL14 Hc t (d) f47 fffatat *471 f mqi-1 t (e) LT cit =414 tr*-4 PriztvItrqut LT tl 317 TIFF: 317U (f) XLPE "4-4PN T 7f94 t (g) -14 1f-4 74 f pikcik-p-aqdr (h).#7t cw.t> critm A s4 cuo 41 ch(111 t1 (i) ftto TrirVq7 (*A 711hqui rchq t U) LT trk ila0 mtilq ichqr Am' t (k) r11s ebk;7t5.17 4,(4 crw v c11.01 t1 (1) W.1 41 TOT ~i X11 a1-731-t-e Tfcffit* fttit A1c11 t1 (m) 1:014 *491 a'-1 *-491* adlti OEE-002 8

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