Transformer Without Shipping Bolts – Destroyed
MIDWEST bought a 500 kva general purpose dry transformer that was taken out of service as part of an expansion job. The transformer was well secured to a large wood pallet. It was wrapped in plastic and looked great when it came in our door. It was a used transformer, but looked like a brand new transformer, except for two knockout holes and a strange bulge on one side. When our switchgear shop checked it out, they found the shipping bolts had not been replaced before shipping. The transformer was now a boat anchor. A very large boat anchor. New dry type transformers are shipped from the manufacturer with bolts holding the core and coil assembly to the base frame. After installation, these shipping bolts are removed so the transformer sits on absorbent pads that minimize vibration transfer from the energized transformer windings to the transformer enclosure. But, if you move the transformer without replacing these hold down bolts, the transformer core and coils are just setting on a frame and they will trip over, inside the enclosure, the first time the truck goes around a sharp corner or stops suddenly. As soon as the outer high voltage windings hit the inside of the enclosure, the transformer becomes expensive junk.