[SOLVED] Need Help for wiring ups transformer

[billouris]

hi guys. i'm new to this forum and i really love it so far! thank you all for contributing to general and specific knowledge

i need some help understanding this transformer! its from a 1000va ups.. i found a similar post but i didnt understand ! sorry but i am kind of a newbie .. but with a great passion for electricity. so... it has 7 wires on one side and 3 10awg wires on the other... what do i connect where? ? ? ? ? i'm guessing its 24v DC .. and i have 220v mains.

i am thinking of using this transformer in a bench power supply i'll make.


thank you all again.

 

[chuckey]

The three 10 awg wires are the low voltage side. The 7 wires that form the secondary need their resistance measured. One will go to the frame which is the earth wire, that leaves 6 to sort out. If the transformer was for 220V only, it would have a neutral connection then the live connection (s), so they could be for 200V, 210, 220, 230, 240. It is more likely that the transformer is designed for dual voltage working, so it has two sets of primary windings which are put in parallel for 110V and series for 220V. So if its a 110V transformer each winding might be :- neutral, 100V, 110, 120.
If you measure the resistance of a secondary winding, it will go some thing like :- common to 20,21,22.9. The big change of resistance is between the neutral and the first voltage out.
You do not say what your local mains is. For safety, connect a wire to each "neutral" and each highest resistance tap, so you have four wires. For 220V working connect a neutral to the high voltage tap on the other winding, then feed the mains into the other two wires. So resistance wise it will go :- common - 22.9 connected to other common , high voltage (45.8).
If you need it to work on 110V, connect the two commons together and the two high voltage taps and feed the mains into them. If you are unsure, wire a 60W light bulb in series with series with the mains, if you have made a mistake, the light bulb will come on full brilliance, if all is OK the light bulb will be very dim or out.
Once you can put mains on the transformer, measure the output voltage on the secondary. It will probabley read some like common 12V, 24 V, or common 12V, 12V. This means its a centre tapped transformer, where in the first case the common and 24V wires go to the diodes or in the second case both the 12Vs go to their diodes. If the voltages are in any other ratio, i.e. common 10v, 38V, then its a multi voltage secondary and each winding needs to go a bridge rectifier.
Frank

 

[billouris]

thank you very much chuckey. appreciate it .. i figured it out.