what is the difference between on line & off line UPS
Answers were Sorted based on User's Feedback
Answer / myo
There are two type of ups 1. semi-auto ups which is structured by solid relay .when the ac power supply is out,it change to dc supply and convert the ac out put. It has off period time is 20 milli second.so, this type is called by off line ups. 2, is fully auto ups which has structured by electronic switching device which has not off time period. so, this type is called by online ups.
| Is This Answer Correct ? | 4 Yes | 1 No |
in on-line ups the inverter will be always ON.the power
flows from supply to load through battery and inverter.but
in off-line ups inverter will be ON only when supply is
cutoff.in this power flows directly to the load through a
seperate static switch..
The inverter in on-line should be high efficient and also
change over time is very less in online ups than offline..
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / simon
Online UPS means that there is a in built stabilizer which remains always in on Pos <the over all supply will b stabilized >.Its Opp in Offline.
| Is This Answer Correct ? | 0 Yes | 0 No |
What does the kvar means?
is dc transformer is possible ?
How to calculate fault level of 11 KV system
megger generates D.C. voltage while earth tester generates A.C.voltage is it true? I know for megger it is D.C generator but what about earth tester?
What is the Procedure for selecting a Cable, Breaker and Transformer for particular load.
Why a tesa lamp is glow between two phase?
Why IR value of the (HT cable Plus synchronous motor) is less while individually having IR values in GΩ?
if any one phase of the 11kv/415v distribution transformer not delivering the supply voltage what will happen
difference between ac and dc generators
Based on CPI/CGPA they shortlist the candidates & than directly start Interview so there is no Written Exam or GD Only PI.Interview held @ MNNIT , ALLAHABAD On-Campus on 6th,Aug, 2007 & the Questions asked to me by Interview Board ( 4 People) are from HR/SummerTraining/BTP/Subject-core, POWER SYSTEM & MACHINE. time duration of I/V is about 15-20 Minutes. HR- Q.1 Name,hobbies & About family background ? Q2.What u know abt NTPC ?? Q3.Why u want to choose NTPC as ur Carrier's starting i.e power sector not any other Oragnisation or sector ?? Techincal Questions- Q1.What is the reason for transformer Noise ?? Q2.Which material is used for making Transformer oil & How u measure its dielectric strength & Name the test ? Q.3 Which Machine u will prefer 2 use if flammble gases are coming out at a place & why ?? Q4.What is relation b/w Transmission Lines & Communication Lines ? Q5.What is the maximum capacity Synchronus Machine & total powerGeneration in our country ? Q.6 In india Power generation is at 50Hz while in America its 60 hz ,why so ?? Advantage or disadvantage ?? Q.7 Maximum Generation Voltage in india ? Q8. What is the Voltage regulation & why its required n how much is permissible ? & causes of voltage variation ?? Q.9 Why electric shock is feel ?? n in a Electric Train why we didnt feel that ? Q.10 Have u seen/ experience of any power plant/ industry related to the power sector ? so these are the questions which not too diffcult i think was asked to me.
what is difference between AC VVVF drive & Dc VVVF drive explain their working principle?
Why battery rooms painted with dark colour
1 Answers BAL, MSETCL Maharashtra State Electricity Transmission Co Ltd, Polycab,
Civil Engineering (5086)
Mechanical Engineering (4456)
Electrical Engineering (16639)
Electronics Communications (3918)
Chemical Engineering (1095)
Aeronautical Engineering (239)
Bio Engineering (96)
Metallurgy (361)
Industrial Engineering (259)
Instrumentation (3014)
Automobile Engineering (332)
Mechatronics Engineering (97)
Marine Engineering (124)
Power Plant Engineering (172)
Textile Engineering (575)
Production Engineering (25)
Satellite Systems Engineering (106)
Engineering AllOther (1379)