Answer / ruben

UPS has internal bypass and used if in case there is some
problem within the UPS, ie. overload. the load will be
automatically fed from the bypass circuit. the maintenance
bypass is an external circuit or feeder that is use to feed
the load (bypassing the UPS). this will allow the user to
remove completely remove the UPS from the network/system for
maintenance or replacement.

Why do we need interlocking in a HT metering or Ring main unit switchgear?

0 Answers  

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what happens if sf6ckt breaker gas pressure is high or low about the actual rating of gas pressure(5kg/cm2)

2 Answers  

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how do find power factor in practically and what it means?

3 Answers  

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what is the formulae for selcting capacitor bank to increas pf

4 Answers  

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what is the ka rating of mccb. and how it is decided .

3 Answers   Napino,

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what is V0/V rating of cable

1 Answers  

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In 110V DC supply,if a closed circuit gets open, How can we identify the voltage which is measured after the resistor(4KOhm) which is open with negative.it shows 55V +ve when measured, also the actual positive source is 55V +ve .Because there is no voltage drop in open circuit. How can we identify whether this is the voltage which is series with the resistor or the DC source direct +ve.

1 Answers   GE,

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control wiring purpose,standards, ferrule code standard, interlock, schematic, symbol

1 Answers  

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how to determine the size of power cable according to load current

1 Answers   JSW,

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why we did not get shock by touching nuetral of any single phase supply of a electrical equipement?

6 Answers  

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what is the difference between id fans and fd fans

12 Answers   Perkins Thermal Systems,

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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.

0 Answers   Premier,

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