Substation LV Distribution Scheme
Substation LV Distribution Scheme
(OP)
In a substation, the LV system is composed of two redundant auxiliary transformers with two incomer CBs and bus tie CB to support N-1 system security (2/3 ATS). However, when connecting sub-distribution boards with one incomer feeder the system security on the subs will be just N. Some local utilities require a duplicate redundant incoming feeders from main AC/DC DBs two buses to subs to keep the downstream security at N-1 level as well.
If the local standards don't require this duplication and the contactor is not happy to do so (extra cable+2 CBs+ATS cost), the downstream loads / subs will be left with N security, the contractor justifies his point as most of loads has only one supply! but I personally think that it will waste the idea of Aux.transformer redundancy in case of bus fault.
any clues?
If the local standards don't require this duplication and the contactor is not happy to do so (extra cable+2 CBs+ATS cost), the downstream loads / subs will be left with N security, the contractor justifies his point as most of loads has only one supply! but I personally think that it will waste the idea of Aux.transformer redundancy in case of bus fault.
any clues?






RE: Substation LV Distribution Scheme
If it's not required by code, and you didn't specifically require it, why do you think the contractor should have to pay for it?
RE: Substation LV Distribution Scheme
Does this imply the requirement of duplicate supply for all other sub-distribution boards?