Multi-winding transformer problem

it may be a center tapped transformer, the center of the winding ( 3rd wire) may be already connected to ground. So you will need only two diodes for rectifier or it can be for a dual voltage source. when you measure A/C value in this case you will get the same voltage between both terminals. try to measure accross both wires, you may see a value two times.

Thanks for the reply Mbarazeen.

From your last sentence, I take it that you asking for the voltage to be measured across the two wires labelled AC INPUT in the above diagram. Is this correct?
This voltage is coming at 0V.

I am trying to understand the usage of a multiple-winding transformer in the above circuit. The input power to the circuit comes from two output terminals of the transformer both of which are at similar voltage with respect to ground.

My understanding of electric circuits is good enough to realize that for current to flow between two ends to be potential difference between them. In this case, there is none. However, I must be missing something as this is a valid circuit design.

Could someone point out what is amiss in my reasoning here

Thanks giv

It may be going to a relay on the board, is it power stabilizer? you better tell some thing more about on what you are working. if teh board is powered from this AC wires, you will see a rectifier connected to it. since you measure 0V i doubt it is for different purpose. do you have some more information?

I am basically debugging an Uninterruptable Power Supply (UPS) which stopped working after a power surge on the AC mains.

Should I paste all the modules contained in the system?

Thanks

in a UPS there may be more than one transformer based on the type. the transformer on the picture is relatively small and may be for powering the controller.
Some transformers are built with a thermal fuse embedded in the winding for safety purpose, but not easy to replace, but this can be by passed.

I do not know how expert you are to troubleshoot, do you have any instrument such a multimeter etc?

some checks are performed after plugging it to power - voltage measurements
some checks are done after opening the connectors - resistance checks etc

what you have to trace first is the supply to the control board

I have pasted the entire system below in case it helps.

The transformer above is the biggest in the system. In the picture below, its under the two light yellow boards.

I do have a voltmeter.

Thanks

Here is a good video tutorial for visualizing 3 phase power transformer. http://gpac.link/1CmqVr5 (http://generalpac.com)

It also has very description for which direction the current flows, how to measure the voltage per phase vs line-to-line etc etc

Hope this helps!

As i see, there are 2 small transformers one is on the top board and another on the green board on the bottom. make sure both transformers are getting voltage to input and they put out put too.

if those are ok and the controller part is getting powered up, then most probably your thyristors are damaged. you have to check all of them one by one after removing. those are like transistors , on the top of your picture mounted on heat sink.

you should have some knowledge and skill to get everything done. Also you need proper tools for checks.