Dryer blowing fuses
 

Last few days.

When we first moved in, it did that a few times, but quit and worked fine, been here a few years now. Will run for about 10-15 minutes, then trips breaker. It is two 40 amp 110 fuses together to make the 220 for the clothes dryer. I suppose the element for the thing could decay and increase the resistance, probably a spec for that; if that is not the case, do fuses go bad? I guess they would, but wouldn't they go all at once

A dryer is usually a 30 amp circuit. Used to be three-wire, now needs to be 4-wire.
I'd first check all connections in the panel, receptacle, plug, and dryer. A loose connection=high current draw.

Breakers do go bad sometimes, but I'm surprised you've got it on two breakers. Might look into what wire is run to the dryer. It might be incorrect.

Do thermal breakers go bad? Yes. What are the symptoms? Exactly what you are seeing. Could this actually be a problem with the dryer? Yes. Should you have a 220 breaker instead of 2 110 breakers, one on each phase? Yes.

Are both phases tripping or just one?

Anyway, replace the breakers with a proper 220 breaker. You should do this whether the dryer is broken or not. If it keeps tripping, then the dryer has a problem.

Now the real question is do you have natural gas in your house, and if so, are you out of your mind having an electric dryer?

With this combo you shoud have a 220v/40A limit. It's the amp draw that trips the breaker. Possibly when the heater kicks in you are momentarily exceeding the 40A limit. Check the rating listed on the dryer. If even one of the breakers is weak ( I would guess the one supplying the heater of the dryer) you coud get this happening. I am guessing the breakers are a bit dated. Like RedBeard says, instll a 220v/30 or 40A breaker that will fit your panel, depending on dryer load.

I replaced a breaker in the garage, and that worked for a while, but it turned out that mice had eaten the wire, causing an intermittent short.

Be vigilant. When I finally found it, about three inches of wire was fried.

The breaker connection itself can corrode. Pull the breaker & check. You can move the wires to an empty place, put in a new breaker there, & blank cover the original.

I see you posted about fuses, too. If screw in or push in can be some corrosion there, too. If you have a fused blade type disconnect, be careful there. The blades can be corroded & stuck so it doesn't disconnect.

I would suspect a bad breaker first; loose connection in the breaker panel, the receptacle the dryer plugs into, or at the lugs that the dryer cord attach to inside the dryer next. Loose connections can increase the current draw and slowly overheat the breaker.
The cooling vents in the motor could be clogged with lint, causing it to overheat (not very common & doesn't always trip a breaker) or it could have a bad bearing, causing it to draw too much current, which would trip the breaker.
The heater is a coil of wire like a spring. Heat cycling and vibration cause it to eventually sag and break. It can break near the end, drop down, and either short against itself or against the frame of the dryer. This makes it shorter by 10 percent or so and causes it to draw too much current. It can work OK except the additional current load eventually trips the breaker. This isn't common, but I've seen it happen.

Again, the dryer should likely be installed on a 30 amp circuit. Check the nameplate for FLA(full load amperage). If it is blowing 40 amp fuses, there is a real problem. I would unplug it and not use the dryer until you find out what is wrong, and go to 30 amp protection. There are very few residential dryers that require a 40 amp circuit in the US.

I have had breakers that went bad, but I have also had a situtation where simply tightening the screw terminal where the wire connects to the breaker was the problem. I would check for loose terminal screws before doing anything else. Just make sure you do it safely!

There are tons of small terminals inside the drier that can loosen and cause this problem. If you pull the back panel off the drier and open up the back of the control section you may find loose connections and melted wire. Driers operate with a lot of vibration so bad connections should eventually be expected.
If the two breakers are not mechanically linked together, they should be. When one trips it will break the other side as well.
Good idea to check the wiring at the panel and the wire gauge to the plug and to the drier as well.
I replaced sections of wire and terminals in my old drier right up to the time I installed a gas drier. Every time I replaced a defective wire/terminal the next weak link would step up to make sure my clothes stayed wet...

Just went out and looked again, it is two 50 amp linked together, the stove is on two 30s linked together. Sometimes it just trips the one for the heater, and the dryer keeps turning.

The switching it out to a real 220 fuse instead of that bridged BS, has been on my list of stuff to take care of for a while. Gas dryer would probably save a sack of cash anyway, maybe I need to go shopping. Needs to quit raining before I am messing with any fuse boxes.

A stove/range/oven is usually on a 50 amp circuit, and the dryer is usually on a 30 amp. Any way they could have been switched?

Whoa!

OK, if the heater element is popping the breaker, then the issue is the loose connection, I virtually guarantee it. I also expect you are going to find burned connections some place.

Go buy a Gas Dryer.

Yeow! The dryer should be two 30s and an electric range should be on 2 40s. My advice is the same as above, except I would turn those breakers off now and not turn them back on until I found out what was wrong and wired that box properly. Power the dryer with 30 amp breakers, the range with 40s.

The heating element is usually across the 220 so it would blow both fuses. With split phase power distribution there is no such thing as a single 220 fuse. It sounds like you have something wrong with some of the ancillary equipment like the timer or light etc.