When we use air circuit breaker, it has O/L protection ,time delay SC protection, Instataneous SC protection & ground fault protection. They all have some setting range. But what is the suitable/allowable setting for the above protection which will be safe for the equipment? For example-O/L protection setting have a range of (0.4,0.45,0.5,0.55,0.6,0.65,0.7,0.8,0.9,1.0)xIn Time delay SC protection have a range of (1.25,1.5,2,3,4,6,8,10,12)xIn Time delay setting is 0.02,0.1,0.2,0.3,0.4 Instataneous setting is fixed to 20xIn Gound fault setting is given 100A,300A,600A,900A,1200A This setting are for 2500A ACB. So what will be the basic allowable setting for the above protection? is there any formulae to calculate this<
1596Why the meters sonnected to metering core of CT are not damagedon event of a fault??? Explain the phenomena??
1 4003How to determine earth fault level to set relay for a normal distribution system of 11 kV , 100 A load????????
TCS,
1 3412Why the Transformer connection is changing in different transformer?(Like Star & Delta,Delta & Delta,Star & Star,Delta Star) From that connection where it is used?
2 59701)What will happen when 240 VDC supply is connected to 240VAC supply(DC supply +ve is connected to phase of AC supply & DC supply is to neutral of AC supply). 2)Also what will happen when 240 VDC supply is connected to 240 VAC supply in reverse polarity as of Sr. No 1.
2 3876What will happen when more than one star neutral points at same voltage level are connected to earth by metallic conductor?
TCS,
1 3257What is the unit of inertia constant of rotating machines? Which has more inertia constant between turboalternator and hydroaltermanor and why?
2 15423Can the efficiency of transformer be measured with the help of wattmeter readings taken at primary and secondary side? Support the answer.
2 3623Classical power system stability was mainly focussed on rotor angle stability but modern power system stability has more focus on voltage stability.Why?
4 6081Post New Electrical Engineering Questions
Define bibo stability.
Draw a SLD of DG distribution up to main LT panel?
Which capacitor is preferred for high voltage and frequency?
How to protect a Dosing pumps/any sensitive equipment (single phase) from surge protection inside a food factory.
Operation of isolators.
I am going to appear for the RRB Chennai junior Engineer online exam. Please send me the previous exams question papers (also solved) to my mail id: rrkhandhar@yahoo.com
What is the height of DA, DAL, DB, DC & DDE tower?
how to calculate earth fault relay current and CBCT ratio
HOW TO DESIGN THE body EARTH cable(Copper Conductor) size for 60KVA UPS?
is there any device that works properly accept relay, it may be fuse but if i want fuse of 33kv 300 amp it is avaliable, pls give me details
Application Comparison between 22KV (UE)and 33KV (E) system. Are we allowed to use 33KV (E) cable in lieu of 22KV (UE) cable. What are the technical disadvantages.
CALCULATE THE TOTAL VOLTAGE DROP AND SELECT THE CABLE SIZE IN MM-SQARE FOR A PANEL-262KW AT 110 METER FROM THE SOURCE SUPPLY , SUPPLY VOLTAGE 240/415
Which motor will you choose which can operate in both lagging as well as leading power factors?
Application Comparison between 22KV (UE)and 33KV (E) system. Are we allowed to use 33KV (E) cable in lieu of 22KV (UE) cable. What are the technical disadvantages.
what is differant beetween overload current and phase current?
