Substation Installation Choices

[yjacket]

What are the advantages/disadvantages/potential problems that need to be addressed when choosing between the following installations? Cost and redundancy need not be addressed.

The installation of a single 4000kVA transformer or two 2000kVA transformers.

 

[jlazucena]

jlazucena

4000kva advantages
only one main breaker high side
only one main breaker low side
only one set of relays
only one SWGR
no problem about getting load balanced
no problem about getting one XFMR overloaded while the other has spare capacity

2x2000 advantages
smaller short circuit current in the secondary

If a capacitor bank is considered and you have some VFD (harmonic production)you can put most of these VFD in one XFMR and have the other XFMR a rather clean

 

[towkay238]

As mentioned by jlazucena these items translate to initial equipment cost and a larger substation space. However two units mean that you have operational flexibility.

 

[jbartos]

Suggestion: Beside what was mentioned in the first reply post, there is a need for more info regarding those two 2000kVA transformers, namely, how they will supply load, whether they will have their secondary in parallel, etc. Please, elaborate.

 

[jlgordon]

Dual Trfs. allow offers the ability to automatically roll load to an alternate power source source within just a few cycles versus waiting for field repairs.