Having an issue with my dryer that started over the weekend.

Dryer cycles normally with high heat for about 7-8 minutes and then single household fuse blows. Fuse panel has a pair of 30amp D fuses and then a breakout box for dryer that has a second pair of two time delay 30 amp fuses...the red wire side keeps blowing, black doesn't have any issues. Dryer still operates after fuse blows, but with no heat.

Took dryer apart, cleaned it all out. Cleaned out the ventilation duct and airway isn't obstructed.

Repair person told me I could try replacing the heater. I had a spare heater so I swapped the part out and started it up without the ventilation duct attached to see if problem persisted. I could see the same fuse in the fusebox looking like it was going to pop.

I'm having an electrician come out to the house to check the fusebox, but in the meantime I was wondering if there's anything I might have missed on the dryer side that I could look at beforehand so if Electrician call isn't needed I can cancel it...Could the High limit thermostat be the issue?

Thanks for any help.