I want to connect such a low-value resistive load to a transformer that it draws ~1.6x the rated output current but I'll only do so for short periods of time so the transformer won't overheat. Aside from a drop in output voltage, is there anything that could occur that I should be aware of or transformers don't care as long as they stay cool?
I'm DIY-ing a JBC soldering station similar to Unisolder and MarcoReps' design and I have a question about the transformer VA rating that I need. This all started when I designed my station around a 130VA, 20V transformer and it worked really well, but the transformer barely got warm to the touch(IR thermometer clocked it at 36C) even when running at a high duty cycle while trying to heat a large copper bar. My iron works very similarly to JBC's and the above DIY designs where it only passes half or full waves to the iron with no phase control, reducing noise and interference.
This analysis of the internals of one of the JBC stations reveals that it only has an ~80VA transformer despite the station being listed as a 130W station. Further, based on the Vp values measured, the transformer appears to only output ~18Vrms under load instead of the 23.5V listed on the product page. I do see this other post about the power rating, so I understand to an extent how the voltage numbers make sense, but the power numbers still don't.
Based on all this, how would my transformer behave when I exceed the output current limit? My choice of 80VA, 18V transformer has an output current rating of ~4.4Arms. But the 2.5ohm cold-resistance of the tip would result in a 7.2Arms draw at least when the tip is still cold. From my research, the VA rating for large grid transformer applications is based on heating effects which won't be an issue for me since I'll be operating at very low duty cycles for the most part and my time-averaged power will be <80VA. However, could anything else occur due to these larger current draws? I was thinking saturation of the magnetic field in the core could play a role here? Will this just manifest as a slightly lower peak voltage?