Anyone hazzard a guess at the VA rating of this transformer.

[MrBean]

I got this transformer. Input is 240V.

AC Outputs are

32V across yellow wires
13V red-----red/yellow stripe
13V red-----red/yellow stripe
26V red-----red

I've ignored the bridge readings as they will be DC

A 6" ruler is shown in the picture. Laminates are 4.5" width, 3.75 height, 2" depth.

Thanks for any help.

Regards Terry.....

[Al_The_Man]

My guess would be around 750va.
Al

[MrBean]

Thanks AL. I thought you'd be able to make a good estimate for me. Much appreciated

Cheers

Regards Terry.....

[murphy625]

I dont have much experience with the "appliance" type transformers but a VA is a VA and a transformer of that size would be ~150VA im guessing.

Plug it in, put on a load and monitor the temperature.

Good luck.

[Al_The_Man]

The problem is that different transformer manufacturers rate the same size transformer differently. There is no industry definition of "VA rating." One mfgr will calculate his rating when the transformer is working sufficiently hard to raise its temperature 30 degrees Celsius. A second manufacturer, with the same transformer, will calculate his at a 60 degree C rise above room temperature. The first, conservative, manufacturer will call his transformer a "900VA" transformer. The second, who rates his at a higher temperature, will call his a "1800 VA" transformer. Same transformer. The transformer is probabally the Hardiest component in your system as far as taking abuse, but its biggest enemy is heat, this is due to excessive current, one factor on a full wave rectified DC system that affects the VA rating is going too high on smoothing capacitors, it is tempting to shoot for close to 0% ripple but the downside is a possible doubling of the VA required, unfortunately the capacitor manufacturers often specify the tolerance of there caps as -0%,+100% so it is easy to go over. The upside is that in most applications seen on these forums, the current never stays at the maximum for extended periods of time and therefore a factor called nominal VA comes in to play.
The bottom line is to monitor the temperature and use your nose to detect the smell of insulation begining to cook.
Al