I have purchased a cheap secondhand transformer for an experiment that i hope i have chosen correctly?
If i am wrong please belt me across the ears at any stage!

I need to make sure i have the right thing not being sure about transformers & need some advice & also to make sure i have the wiring side of things correct before i go ahead.

I am hoping this is a Step-Down Transformer with the Output 12v AC 150amp as marked on it.

I have attached a couple of blury pictures of both sides of the transformer to show the connecting poles.

On one side --- Input side of the Transformer there are 5 poles marked:

( 0 100v 115v 220v 240v )

Our Mains power is 240v AC so, for the correct wiring as i see it, i connect:
The ACTIVE wire to the 240v pole,
The NEUTRAL wire to the 0 pole,
& the EARTH wire to the Chassis.

Is this correct?

I actually want to control this Transformer with a 240v AC 10amp VARIAC so i can vary the output.



On the other side --- output side of the Transformer there are two poles, for the ACTIVE & NEUTRAL wires. If this is correct doe's it make any difference what the ACTIVE or NEUTRAL poles are as they are not marked?

Thanks

Attached Images

	part 003.jpg (256.4 KB, 28 views)
	part 005.jpg (247.6 KB, 25 views)

 

That is correct.

The output 12 volts at 150 Ampères equals to 1800 VA or Watts
Your primary current will be 7.5 Amps at 240 Volts.

A 10 Amp variac should be fine.

We call the (poles) Taps in the trade

Regards, Raymond

__________________
There are more ways to get to Rome.

Electricity, Electric clocks, Meters and Trains are great.

 

To check the secondary voltage, use a voltmeter.
It may be a little higher than 12 volts with no load connected to the TX.

The polarity doesn't matter here.

It pays also to check that the primary and secondary coils are insulated properly from each other. It looks as a TX with 2 separate windings from your photo.
And it is a step down TX according to the data from the photo.

What are you planning to drive with it !!

__________________
There are more ways to get to Rome.

Electricity, Electric clocks, Meters and Trains are great.

 

Looks good codan!
Though I would test the used tranformer first -to assure it is working properly. An ohm-meter will let you know if there are any short circuits between any winding and the transformer core. Though testing for any possible short circuits between wire windings will have to be done by monitoring the power in/out-which is approximately equal (assumming high 90`s efficeincy). Using your variac set low (slowly stepping up), with no load attached measure the output voltage. If all is good, attach a load and test again. Also, the output is isolated from the hot and neutral-therefore they are electrically the same.

 

Thanks Raymond,

I have checked the Primary & Secondary windings to make sure there isolated from each other, i only used a multimeter continuity test though.
According to that the insulation is ok.

TX ? What does this mean, Coils? I thought it meant Transmit coil or is it one & the same?
Like RX is Reciever Coil is it not?

" What are you planning to drive with it !! "

I have designed & built a small eddy current retarder -- electromagnetic brake for a small dyno which will require around 12vDC & 100amps or better for full load.
I need to rectify the AC from the Transformer via an AC/DC convertor. This will get me testing some things, the Variac will manually vary the output for the load.

Once i can test some things i will then try to control it with electronics & then onto computer. This is a long way off though as i am still fumbling around like a real novice with learning the electronics side of things.

Only one way to learn though!

 

Thanks second286,

I will certainly take your advice on checking things out properly, like mentioed i have only done a continuity test with a multimeter. I will check things out properly now though.

 

TX is just short for transformer.

Cheers, Raymond

__________________
There are more ways to get to Rome.

Electricity, Electric clocks, Meters and Trains are great.

 

on the secondary side, it says 150A INT, so it is not continuously rated. It may well give 100A continuous though. It really depends how intermittent the 150A loading was intended to be. Ideally you need to know the duty cycle and time frame.

it's a big beastie though, so will warm up slowly. just keep an eye on how warm it gets. if you can't keep your hand on it, then kee both eyes on it

__________________
Transformers are work
Electronics is a hobby