Answer Posted / dipak thumar-baroda
grounding and earthing both are for providing path for
electrical current to earth but grounding is for return
current either from neutral or for some protective schemes
where as earthing is for leakage current under healthy
condition.
| Is This Answer Correct ? | 3 Yes | 1 No |
Post New Answer View All Answers
We have drive feeding an output contactor for a 5000 hp motor @ 5kV application. The motor FLA is 629amps x 1.25% service factor = 786.25 amps The cable that we current have in place between the drive and the output contactor is 350kcmil- MV-105 (parallel cables). Per the NEC table 310.60 (C) (69). This show the cable ampacity is at 615 amps per cable for a rating of 1230 amps. We have derated the cable for the cable tray and the multiple cables application and our calculations show that after the correction factor factor we are at 922amps. 1230 amps x .75% correction factor factor = 922.5 amps. The customer is driving us to then use another safety factor of .25% off of the already derated cable. Can you please provide a longhand calculation for your solution on this application?
why we testing the core balance of the transformer before comissioning?
WHY MOSTLY Rph IS USED FOR CONTROL CIRCUITS AUX. SUPPLY ?
In siemens S7-300 PLC, what is function and function block ? What is the difference between them ? When to use function and when to use function block ?
What is Plank's Law?
Why is the frequency not changed during transformation of electrical energy in a transformer?
what is the main function of capacitors in mccs.
explain with diagram how to protect transformers and substations from over current with help of CT's?
Differnce between negative Pahse SequenceFunction and unbalance Function?
How to select a cable size for particular load?
what is the physical connection of a analog i/p to a analog i/p module (ab plc)and through a analog o/p module(ab plc) to a analog o/p . and how all the process control by scada
what is meant by neutral compensation factor and where it is used
difference between ac series and parallel circuit
there is an alternator 480 k.w, 400v,50hz, 4-wire running on load having leakage alternator body earthed current 38 A. is it within acceptable limit? if yes then give reference if no then how to bring within specified limit
Why current shoots up in the secondary on the knee point voltage during saturation test of CT? How core saturation effects the secondary current (while the primary side is open)? What the logic behind this?