Bidding a job with an older exisiting 480-277/208-120, 112.5 kva transformer is to be used. The specs. ask for a field test to be performed to see if the xfrmr is functionig properly before submitting a bid. Problem is there is no power to the building. Is there anyway to test the unit without powering it up??
Thanx, John.

John,
Megger test, TTR (Transformer turns ratio) can be performed prior to energizing. Most any testing company performs these tests on a normal basis.

John,
If you don't have the equipment and aren't familiar with the procedures, I would definitely do as George suggests and have a testing co preform the checks.

However, I wouldn't incurr these costs at the bid stage as they suggest. I would include the cost to test in my bid and state the additional cost to replace the xfmr should it fail at the bottom of my proposal.