Interested to Buy Any Domain ? << Click Here >> for more details...
Safety measures in air circuit breaker
- 5 Answers
- 6634 Views
- Megatron Solutions, TCS, I also Faced
- E-Mail Answers
Answer Posted / nagendra saladhi
over voltage, under voltage, over current, short circuit current and earth fault current were to be consider at the time of its setting.
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
In a power conditoining unit (inverter) of a solar plant when we measure the d.c. current fed by different strings of solar plates to inverter, the current in the negative wire is less almost by 1 ampere to the current in its positive wire say current in positive wire 5 A , then current in negative wire of the same string is 4 A. Since the current entering should be equal to current leaving then why the current is noticably less in negative wire.
1. A 380 / 220 V r.m.s. 3-phase 4-wire circuit carries loads of 8 + j8.1 ohm; 4 + j4.1 ohm; and 2 +j2.1 ohmin the three phases respectively. The length of the circuit is 100 m, and the resistivity of the phase conductors is 0.0005 Ω/m. The neutral conductor is of the same size as the phase conductors. a) Select a reference angle 0for the first phase. Then write down the three phase voltages in both polar format and complex number format. b) Make appropriate assumptions, and take temperature effects on resistance is insignificant. Calculate the currents in the three phases. (Note: Determine conductor resistance, and apply Kirchhoff’s Voltage Law) Based on the result, suggest a main switch rating for the circuit. c) Show your preferred direction of neutral current in a diagram, and then determine its value. (Note: Apply superposition principle, and Kirchhoff’s Current Law) Use its magnitude to show that in this circuit, the unbalanced load may increase the voltage drop in some of the phases. (Note: Also observe the common volt drip in neutral) State your assumptions, if there are any. d) Suddenly the neutral wire of the circuit is broken. Estimate the new currents in the first phase, i.e. Phase L1. State your assumptions, if there are any.
what is fault level of power system ?
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?
What is maximum power transfer theorem?
How much ph is maintained of water electrolyte which is used in LRS for 1200 kw slipring induction motor ?
Whether it is possible to measure energy at the input of rectifier transformer (12 pulse with very high odd harmonics)
HOW CAN YOU CALCULATE PRACTICAL EFFICIENCY OF A ASYNCHRONOUS INDUCTIONMOTOR OF 7.5KW,& MOTOR IS RUNNING WITH AVOLTAGE OF 410 VOLTS,& TAKING CURENT OF 13 AMPS
What is the tipical Online UPS input voltage for 20 KVA load ( 3 Phase or 1 Phase )? Why ? Explain it...?
Explain thin film resistors and wire-wound resistors
Name two low frequency oscillators?
How to check the cable fault / hv test of transformer cable.
could you measure current in parallel?
What is the reason behind current flow(20 A) in amain earth cable of an SMDB? Is cuurent flow(45A etc) through a neutral cable acceptable?
I want to make street light with solar system ... What may I do for procedure and how much of estimation for each material ... If any one knows guide me and inform this id : aravindd7@gmail.com
