what is the diff. b/w restricted earth fault relay &
standby earthfault relay and where they are used?

Answer Posted / shirish prajapati

The REF and SBEF are two separate protection functions. The
REF will protect the transformer winding and the cables to
the breaker. SBEF is standby earth fault protection. It is
backup protection in case of uncleared faults out on the
network, or earth faults outside the REF zone. It may also
protect the neutral earthing resistor if there is one, and
may act as a cheap busbar protection system by tripping the
LV bus section first and the transformer LV C/B second. Do
you really want to compromise important backup protection
for the cost of a neutral CT? You have the option to get
another CT fitted in the bushing, or if there is a neutral
cable terminated on the bushing you could install a slipover
CT on the cable, or in the NER cable box. Lots of
possibilities, and not very expensive.

Is This Answer Correct ?    31 Yes 8 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Why does amplifier gain reduce?

633


What is meant by Im=30mA@Vk/2. How to know the kee point voltage for CT design

2855


hi plz send me reliance placement papers..i.e electrical technical papers that have been asked in reliance test.

2459


pls tell me function of closing coil of A.C.B.

2881


i want to learn control schedule for 11kv panel? can any one send the detailed control schedule?

1908






What is an alternator impedance value?

2396


EXPLAIN THE ESSENTIAL FACTORS WHICH INFLUENCES THE CHOICE OF SITE FOR A HYDRO ELECTRIC POWER PLANT

1546


We have studied about many techniques for finding the stability of system, ROOT LOCUS, ROUTH, BODE PLOT, POLER PLOT etc. In these which is used where. what are the difference among them... PLZ tell me.......

1665


what is the use of piston rings in the engine used for a generator...........

1684


what is the minimum recommended leakage current of an earthed cable connected to the body or skid of an alternator

1549


armature is that part in which current is induced since in dc motor we supply current to the conductor so why we call it armature?

1412


What are the section criteria for cables. Now everywhere XLPE power cable is used or PVC is also used?.

1224


how many single tension hardware are required on a double circuit transmission tower?

1473


How we calculate DC inducation moter Amp? Sir pls give me formula......

1417


Can we Co-ordinate relay in Load Break switch?

1478