Hi guys , new here and have a quick question on building calcs. I have learned when doing commercial calculations, say you have a 120/208 house panel fed from a 480 system, that you use the total load of the transformer when calculating the 480 volt load and I now have heard that is wrong. Example, if I have a total calculated load of 77KVA on the 120/208 house panel than we have been using a 100KVA transformer and adding that to the 480 load, instead of 77KVA, which way is correct.
Commercial Building Calculation Question
- Thread starter LT1BURB
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- Chapel Hill, NC
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- Retired Electrical Contractor
Are you asking whether or not a transformer can be loaded to 100%?
No, if we are doing building load calculations for a test, and we calculate the load on the house panel at 76 KVA, and the correct transformer size is 100KVA, do we use 76 or 100 for the next part of the calculation, for sizing the 480V panel
ron
Senior Member
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- New York, 40.7514,-73.9925
The load is still the load. 76kVA (or 77kVA as you started the post with)
The oversized transformer can just accommodate the load, it is not actually the load.
The oversized transformer can just accommodate the load, it is not actually the load.
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