TOP-250Y - External Current Limit Resistor scaling factor?

Transformer was intended for use with TOP204Y (Not TOP250) and a different output power. You need to download our transformer design tool PI Expert which is under the Support section and design appropriate transformer for you specific requirements

Please answer to my qwestion.

What I can use "scaling factor"?

TOP250Y: "scaling factor"==6.32 --- whot is ???

External Current Limit Resistor:
1) 10k * 6.32 ???
2) 10k / 6.32 ???

From graph in TOP-GX data sheet (Fig 54-B) you can easily see that 10k will give max reduction (due to tolerance)of 0.7. So TOP250 with a minimum uncompensated Ilim of 5.86A we get 4.12A when Top250 X pin is terminated to ground with a 10K resistor. 4.12A is considerably higher than the TOP204 Ilim of 2.25A and this defintitely puts your design in danger of saturating core of transformer which often can result in blow-up of device. The fact that you cannot deliver much power may be related to excess flux density or you may have left the frequency pin of TOP-GX floating - needs to be grounded for 132kHz operation.

Why do you need to use TOP250? Why not use something closer to TOP204 like a TOP226? Also the Premier transformer in intended for 100kHz operation (TOP-GX is 132kHz)and the intended max ouput power of this particular transformer is less than what you need.
Neither the transformer nor the TOP-GX device you have selected are a good fit for what you require. PI-Expert software can help you make a better design....