Maximum Demand in a Single feeder at 11kV feeder

it appears that the current for 4500KVA at 11KV will be around 400 to 500 A if the feeder can tolerate 1250A , so it should be O.K to use it for 500A

From this, and the other question about trench requirements, it seems that Kerala needs to update its electrical standards. Maybe more emphasis on technical issues, and less on restricting larger facilities. [??]

I second your opinion! Kerala Electrical Inspectorate Authorities are unreasonable in thier demands. They need to update themselves.

Interesting...I was sort of guessing, but I thought the clues were pretty good.

Did KSERC give a technical resaon for such restriction on MD?

Your loading would be 236A at max loading of 4.5MVA. So the 1200A breaker is well on top of the job. The only thing I would be concerned about is the reliance on one feeder.

Hi,

Here 11KV side don't have any problem to supply 4.5MVA demand. But, 433V side may have problem considering the FLA and Short circuit current. FLA around 6000A and short circuit amp approx.86kA (considering 7% impedence). 4.5MVA transformer with 433V secondary and 7200A, 433V LV side breaker (100KA rating) are not readily availble in the market. This may be reason for the restriction.

Thanks,

Mari.

Dear Mari,

This is the exact reason why there is restirction of Maximum Demand in a particular voltage level.The same is applicable also in respect of the transformer capacity of Utility company from where H.T. power supply is providing.

Thanks,

Manindra