noanoa

26

hace 5 años

friend the red wires at the entrance and there are 120V
The black and blue wires measures: 14.15V
12.93V black and yellow cables and the other 4.33V yellow
So if the transformer is failing or are you recommending me? what other test can i do

Ennio Montenegro.

44.317

hace 5 años

With the transformer de-energized, measure the ohmic resistance between the black and the 2 yellow wires.
It should not measure resistance. If it measures a low value, it is that they are short-circuited between the secondary ones.

noanoa

26

hace 5 años

I already measured ohmica with the black wire and the two yellow ones and it doesn't measure anything, so it's good?

Ennio Montenegro.

44.317

hace 5 años

Yes, what should be by induction.
Between the yellow wires you can measure close to 9V.
You can also put a resistance between black and yellow that measures 12.93V and when measuring voltage on the resistance, you should no longer measure 12V.

Pilaraprendiz

933

hace 5 años

Sorry to intrude me, but I don't understand.
The secindario carries 2 independent threads, one of them, the one that outputs through the blue wires, has the black wire in common, with this as a reference, 12vac must be had in each of the blue wires.
The other winding is the one that comes out on the yellow wires and the voltage between the two yellows must be 8.5 vac.
It is not correct to measure from the blue wires to the yellow wires, or from the yellow wires to the black wire, because as part of independent windings, it will give you a hermetic reading and lacking any validity.

Ennio Montenegro.

44.317

hace 5 años

Correct Pilar ... !!!
That is why he was told the measures to be taken to rule out the failure he mentions.
Among the failures of a transformer is the contact between a secondary and another.
It is clear that in this case it can be induction, but it must be corroborated.

noanoa

26

hace 5 años

Good friend
I come back again and measure as you tell me
yellow wires: 9.98v
blue and black: 14v
blue and blue: 0
So friend according to that data if the transformer is in good condition or is the fault somewhere else?

Ennio Montenegro.

44.317

hace 5 años

Correct, you must look elsewhere.
When there is a transformer with secondary with central branch, between the ends (blue wires) you can measure double 28V or 0V, as is your case. But between each blue and black wire you must measure 14V.
Check the voltage at the output of the rectifiers and voltage regulators if any.

noanoa

26

hace 5 años

ready friend thanks, tomorrow I upload an image of what the transformer feeds to have if you can help me, in advance Thank you.