what is the difference between Ith & Iu rating in MCCB. Particularly on SACE ABB Circuit Breaker?2 13809
I have an existing old MCCB. ABB Model SACE, the rating are: Ue = 660 volts, Iu =1250 Amps, 3 poles, Ith (max) =800 amps at 45 deg C. I need a circuit breaker for my 3 phase motors, 380 volts 60 hz. the supplier required the minimum ampacity of the breaker to be 911 amps. can i use this breaker with rating of Iu =1250 amps but Ith = 800amps maximum?1279
Difference Between B Curve & C Curve in MCB.3 60449
What is the difference between sensitive earth fault and restricted earth fault in power transformers?4 45642
which INDIAN STANDERD in Mention the earth test value?1 2911
what is the reason for drop in freq. from 50 hz at generating side to 49.8 ,49.6 etc.at receiving side???2 2983
how the rotating magnetic fieldis produced in induction machines??? give the correct explanation.is there any mathematical expression for the same?1 1778
what do you mean by puncturing of insulator by ice -coating?2 2796
If DC supply is given to a transformer it may a) Work b)Not Work c)Give lower voltage than the rated voltage on secondary side. d)burn the winding12 10255
HOW TO CALCULATE AMPs OF CURRENT TRANSFORMER IN HT Panel
Dry type transformers
My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula. formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec. Sp = RT( I x I x t) / K Where Sp – is the cross sectional area of bus bar in millimeters. I - is the value of AC fault current. t - is the operating time of disconnecting device in seconds. K – is the factor depending on the material of the conductor, insulation and initial and final temperature. Value of ‘k’ for copper is 143.
1))why we run three phase or three different circuit from a single conduit 2)) why not two circuit of different phase run in same conduit?? and why we run same three cicuit of same phae run in single conduit??
what is the function and use of cable differential protection relay?
What is force on parallel conductors ?
We have received supplies of the ordered material. payments against the supplies also released. Where ST paid 4% against form C. Meanwhile it has been observed that 25% of material supplied was defective. Please suggest whether the issuance of C form from our side would be stopped till settlement of liabilities.
What are the components connected in between the power supply coming from an electric pole to HT & LT Panels in a large commercial building or how the power supply connected from Electric pole to Transformer & then to the HT & LT panels of a building? Please send me answers via mail, my id is firstname.lastname@example.org. If possible, please give a line diagram.
how to calculate the cable current ratingand and how much of distance the rating will be ok will the distance is incresed what the action we take
what is Fault level? why it is calculated? how will u decide same for our plant?
Damping resistor provided in open delta (tartiary) winding of a measuring PT at the incoming of a MV inverter drive panel is getting heated up. Can any body explain the reasons and suggest the remedy?
how could we know the size of cable by physical view?
DEAR SIR/MADAM,CLEARLY EXPLAIN ABOUT CRAWLING AND COGGING EFFECTS IN INDUCTION MOTOR.
what are all types of cross section in AC cables?
define reflection method?
What are the advantages of nichols chart?