• FIRST MAKE SURE THE MACHINE IS SAFE!
• A TX failure or short is the most dangerous way to get exposed to high voltage outside of the machine.
• This is easy to do. With the power off make sure there is no voltage on either side of the secondary. If you don't understand then don't try it on your own. If you can not turn the machine on without blowing the fuze or breaker then leave it off and assume the TX is shorted out. If you can turn it on you still need to check the TX for no or very low voltage on the secondary. Any voltage above 30 amps should be considered not safe.
• Never put a tap switch in the middle of settings.
• Check water flow with a visible indicator.
• One side of the TX secondary and the TX case sould be grounded or have special safety protection devices and disconnects.
• Remember that the problem could be the controller/timer.

There are many ways to check a TX for different things. Mostly a transformer will fail or give poor performance if it is 1/2 cycled, gets DC type lopsided input and saturates, does not get cooled properly, or gets old and the internal isolation starts to fail.

A growling or extra noisy TX is from 1/2 cycling and is a problem for the TX, that could hurt the TX, but the root cause is the firing board or timer/controller.

When operating, transformers should have a slight hum that is to the frequesncy of the A/C power going through them. If you have MFDC then the hum is more like a high pitched squeek. It will change volume with higher % heat and/or current settings.

Click on the following for more TX trouble shooting information.