The high-voltage rectifiers are located inside the high-voltage
transformer where extremely dangerous voltages are produced during
system operation. It is vital to ensure all personnel in the area of the
a. Make sure power to the generator is locked in the off position at the system
main-disconnect switch. Tag the switch to notify all personnel that maintenance is in
b. Disconnect all cables from the auxiliary cabinet and remove the four screws
holding the cabinet on the top of the transformer. Lift the cabinet from the transformer.
c. Disconnect the three-prong power plug from the top of the high-voltage
transformer. Do not disconnect the twelve-pin auxiliary plug.
Label and disconnect all four X-ray tube high-voltage cables from the
transformer. These cables often store a potentially fatal electrical
charge. Use a shorting bar or other similar device to discharge each
cable as it is disconnected.
The high-voltage transformer housing is filled with highly purified
dielectric oil. Impurities in this oil are capable of causing damage to
transformer components when power is applied.
d. While it is not necessary to drain the oil from the transformer to replace the
high-voltage rectifiers, it is important to maintain its purity during the procedure. This
includes not only ensuring impurities do not enter the housing interior, but your hands
and arms must be free of dirt and perspiration before performing the following steps.
e. Thoroughly clean the top of the high-voltage transformer housing. Carefully
remove the access cover from the top of the high-voltage transformer housing. This
cover is fitted with a cork gasket which may have become brittle with age and adhere to
the access cover, transformer housing, or both. Use caution to ensure the screws,
small pieces of cork, or dirt do not fall into the dielectric oil in the transformer housing.