Interesting. There are those who don't understand the reason and design of double ended switchgear. It is careless to asume that both sources are feed such that they can be paralleled. The purpose of the design is based upon 2 separate sources such dependent upon the reliability of each source not that hey can be paralleled. You are assuming that both sources originate from a single source where the primaries of each transformer are being supplied in an identical way. If power is lost from that source what would be the advantage of double ended switchgear if that source of power of lost? Yes, if both ends of the switchgear are feed from the same source in a basically identical manor then you may be correct to 'assume' that you would be able to parallel both ends of the gear without incident.
I asked a question if there is an issue with a very brief loss of power in the time that it takes to open the tie breaker and then close the second end of the switch gear and not risk the possibility of a failure if the two sources are parallel? It does't surprise me that I got no answer.
I have sold double ended switchgear, both LV and MV, for nearly 20 years for a major manufacturer and all were specified and built with K-K interlocks to prevent the paralleling of the two separated sources. I wonder why? For what purpose? Are you aware as to what the purpose of K-K inrlocks are? It intregued me that you would be willing to assume both the risk and liability to attempt to parallel the two separate sources and condone others to do it.
It is important to consider things beyon the end of ones nose and the distribution system and how and why it has been designed. It just isn't limited to the (2) transformers which supply power to the switchgear. It starts upstream from there to their souce of power. Do you know for what that is? Has it been designed such that both sources can be paralleled? Are you assuming that they are?
If you are assuming the results may be more than 'painfull.'
OP says that it is possible to parallel sources, strongly implying that there is no interlock. Only a system that has been carefully engineered would ever be installed like that.
As to what the advantage would be, I have seen many installations where the feed from the utility is from the same substation, but two different feeder breakers. That provides several layers of redundancy in the service to the building.
I have over 35 years designing and specifying such gear, and PE Registration in multiple states.
I wish this board had a grammar checker.
Deciphered version:
Interesting. There are those who don't understand the reason and design of double ended switchgear. It is careless to [assume] that both sources are [fed] such that they can be paralleled. The purpose of the design is based upon 2 separate sources [each] dependent upon the reliability of each source not that [they] can be paralleled. You are assuming that both sources originate from a single source where the primaries of each transformer are being supplied in an identical way. If power is lost from that source what would be the advantage of double ended switchgear if that source of power [is] lost? Yes, if both ends of the switchgear are [fed] from the same source in a basically identical manor then you may be correct to 'assume' that you would be able to parallel both ends of the gear without incident.
I asked a question if there is an issue with a very brief loss of power in the time that it takes to open the tie breaker and then close the second end of the switch gear and not risk the possibility of a failure if the two sources are parallel? It [doesn’t] surprise me that I got no answer.
I have sold double ended switchgear, both LV and MV, for nearly 20 years for a major manufacturer and all were specified and built with K-K interlocks to prevent the paralleling of the two separated sources. I wonder why? For what purpose? Are you aware as to what the purpose of K-K [interlocks is]? It [intrigued] me that you would be willing to assume both the risk and liability to attempt to parallel the two separate sources and condone others to do it.
It is important to consider things [beyond] the end of [one’s] nose and the distribution system and how and why it has been designed. It just isn't limited to the (2) transformers which supply power to the switchgear. It starts upstream from there to their [source] of power. Do you know for [sure] what that is? Has it been designed such that both sources can be paralleled? Are you assuming that they are?
If you are assuming the results may be more than 'painfull.'
