Interested to Buy Any Domain ? << Click Here >> for more details...
what is the difference between Ith & Iu rating in MCCB.
Particularly on SACE ABB Circuit Breaker?
- 2 Answers
- 18468 Views
- Siemens, I also Faced
- E-Mail Answers
Answer Posted / mazed
Extract form appendix K of standard IEC 60947 -2
Voltage
• Ue = Rated operational voltage
• Ui = Rated insulation voltage
• Uimp = Rated impulse withstand voltage
Current
• In = Rated current
• Ith = Conventional free –air thermal current
• Ithe = Conventional enclosed thermal current
Short -Circuit
• Icm = Rated short circuit making capacity
• Icu = Rated ultimate short circuit breaking capacity
• Ics = Rated service short circuit breaking capacity
• Icw = Rated short time withstand current
Trip unit
• Ir = Adjustable overload setting current
• 1.05xIr = Conventional non –tripping current
• 1.30xIr = Conventional tripping current
• Isd = Short time delay tripping setting current
• Ii = Instantaneous tripping setting current
| Is This Answer Correct ? | 8 Yes | 0 No |
Post New Answer View All Answers
what will be the min and max voltage flow from neutral to earth?
why the perameters of secondary circuit are more important then that of the primary circuit of induction motor?
HOW MANY TYPES OF FUSE?
how to modify DOL control panel into Delta Y connection?
what is RFID? thire application;
I WANT BHEL PREVIOUS QUESTION
does buccholz in a transformer use batteries
in 1-phase 230v,how in 3-phase 440v. in each phase in between 230v.
What are the roles and responsibilities of electrical engineer in cement plant
How much kv gas generator is needed to run 2 hp and 1 hp airconditioners, plus a refrigerator and 4 Tvs
a 100mva,400/200v transformer has leakage impdce of 10% draws a steady state line currentof---------------
What Is HO factor in power selection
what is the difference between 4pole & 6pole DC Motors & give advantage ?
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.
I have made a 3 phase thyristor full bridge rectifier. But at the moment it is working only for the half bridge operation. Both the half bridges are on operation separately but when i put it into full bridge operation the oscilloscope output is zero. I rechecked that the pulses are correct for each thyristor. what could be the possible reason for this?
