pansypoo's personal rant page.

Upgrade probably means new wiring. Is that the original stuff like fron 1926 or something more recent?
What is the rating of the circuit breaker - amps?
What are the specifications of the things plugged in? Those are probably in watts, but sometimes given in amps or both.
Does the thing blow when you turn on one last item (if so, which one?) or does it happen after everthing has been on for a while?
 

i think it's 110. so we have to choose. in the livingroom, we can have a teevee and heater. just sit in the glow of both. kitchen? got the fridge, so you blow it if the heater is on and you decide to toast something. also can't microwave and toast. turns out the basement freezer and my computer were on the same fuse-breaker? and was making the OS 9 freeze up. had to move the puter. sigh. worse view.

we did have to replace on outlet. wall was warm and mom's 2nd hubby electrician and fixed it. otherwise, it has done ok. for 1926, they put in a ton of outlets.
 

110 is voltage, unless it's amperage for the whole house, which I doubt.
Lots of outlets doesn't mean you can use them all at the same time.
The real issue is amperage, the amount of current. Each circuit breaker protects one or more outlets and maybe built-in light fixtures and fans. It limits the amount of current that can flow into a circuit. The rating is usually stamped on the breaker. Yours are probably 15.
A 1000 watt microwave oven might draw 1500 watts of power which means about 13 amps.
Your toaster might draw 10 amps.
Can't run them both at the same time. Even if they aren't plugged into the same duplex outlet, the outlets could be protected by the same breaker.
 

luckily we don't use a lot of appliances at one time. so, it's hit and miss when we discover a new issue. sorta can use the microwave and toaster oven on bake. sorta. the micro dims. i guess if we let it run longer it would blow.
 

More current means more heat in the wiring. More heat means more resistance. That might cause dimming in something observable.
What melts, blows or catches fire is problematic.
I had a couple more thoughts, but it would be easier to do with e-mail than in comments. Let me know.
 

i don't think we have a problem except not enough juice. but don't use a lot or don't have anything that would need a lot. now, if we got solar panels and had to tie it in? hmm, that might be an issue. it's jus a fun part of the house, like the deco thermostat. newer one on 1st floor, but i did find the old one in the basement now added to my hoard. alond with the old metal toilet paper roll holder that 'broke'. has a patent on it. one in the house still works.