Dryer's heating element blows fuse.

I have a fairly recent model Whirlpool dryer. I can provide exact model number if needed. The dryer will start up fine, but after a minute or two, it blows one of the two fuses that serve it. At this point, the dryer continues to spin, but loses heat. I checked out the heating element, and it looks fine -- no grounding. I've also checked the path to the vent and it is free of obstruction.

So what else could it be? Some sort of wiring fault? I would be curious as to how something like that would just happen all of a sudden. The dryer worked fine until recently.

If it was a heat sensor problem, would the fuse blow, or would the heating element just stop?

The info on the dryer door says it's 24 amps. We currently have 2x15 amp "mini-breaker" style fuses serving the dryer. We've also had 2 x 30 time delay fuses. We get this problem with either configuration. We were told by an electrician that since the house has only 60 amp service, it would be better to only have 15 amp fuses.

Apologies if this question has been asked elsewhere on the forum, but 10 plus minutes of searching found problems that were similar but not quite the same as this.

 

You also need to take a close look at the fuse box. The socket components must be tight. Years ago I ran into your scenario, and problem was caused by bad old 2-fuse throw-switch box with bad sockets. If there are loose parts, it generates heat right by the fuse.

IF that is not it, then something on that one leg is drawing too much or shorting out, obviously. You'd have to analyze closer, with a fine tooth comb, reviewing your previous checks. If an ohms test on your element says 0, it is shorted out. You have to have some resistance. It should be some real low double digit number. But not 0.

 

Ah, funny you should say that -- that's one element of the problem that slipped my mind while typing up the post. Prior to this problem, the fuse socket in question had this washer dealy break. Turns out it was actually holding the socket together.

So that was my first response. I repaired the socket as best I could by replacing the missing washer. So as of now, the socket is niced and tight, but the problem with the dryer still persists.

So here's one thing I'm not sure of. The washer that broke seemed to be some sort of non-conductive material - a ceramic of some sort with a somewhat rough texture. I wasn't able to find such a piece at the local hardware store, so I fashioned a washer out of some stiff cardboard I had.

As I said, the cardboard washer now makes the socket tight. But the fuse still blows. My inention was not for the cardboard thing to be a permanent fix, but to see if tightening the socket would solve the problem. Is it possible that my makeshift replacement is causing a problem? Looking at the design of the fuse/socket it looks like current wouldn't even touch this part.

Furthermore, what's the deal with fuse panel parts -- my local "big box" style hardware store only had a modern "plug in" style fuse receptacle. Which was not at all helpful. Can one find older fuse panel parts at specialty shops?

 

The nonconductive washer separates the center terminal from the outer thread part of the socket. If they came in contact, the fuse would be bypassed.

Cardboard is not the safe and sound answer and you won't be able to tighten the center screw tight enough. It is also possible you no longer have good contact between the center screw and the female receiver threads for this screw, due to breakdown over time with the current-draw heat generated there. If there is any looseness there, heat will generate, without additional amp draw. I've also seen where the outer threads of the socket no longer create a tight fit with the fuse. It's as if the socket has enlarged to a slightly larger diameter. If the sides of the fuse are not tight in those threads, that generates heat. You can be fooled into thinking the threads are all tight when you bottom the fuse out in the socket.

If I were in your shoes, I'd get the jaws of my amp meter around each set of those dryer fuse socket wires in there and run the dryer and see what the amp draw is. Then you will know if the dryer is causing it or the fuse box.

Then I'd strongly consider buying a circuit breaker panel replacement for the fused one.

 

I agree with ecman, change out that fuse box for a breaker box with a double pole 30 amp breaker, you may even be able to find a 25 amp breaker but that is cutting it close to the rating.
If you are blowing 30 amp fuses then you definately have a problem that needs correcting. I would be checking out the circuit wiring and outlet. It sounds like you have a bad connection somewhere along the line.
It is possible that one of your over temp sensors is bad in the dryer but unlikely. The exhaust sensor would be my first guess if one was bad. There should be a service tech sheet inside the back cover of your dryer to help you locate them.
B

 

Thanks all! Yeah, I knew the carboard fix wouldn't be safe or well advised, it was more to test the theory about the tightness of the socket. So I think my first step now will be to get to an electrical supply store to 1) buy an amp meter and 2) get some parts to better fix the fuse socket.

Going to a breaker would be better, but the whole damn thing needs replacing and the money's just not there. It's one of those jobs that has a domino effect. It's a 60 amp fuse panel, so if we're switching to a breaker, we would pretty much have to go to at the very least 100 amp service, which mean getting the city involved, etc, etc.

I'll be sure to report my findings. Thanks again.

 

But don't you have a separate throw switch fuse box that is downstream from the 60 amp antiquated fuse box? if so, just change out that throw switch box to the circuit breaker kind.

[If you did do that, make sure you do the job safely and pull the doulbe 60-amp buss fuses main on the 60 amp service box, and make sure the lugs and wire feed to the fused dryer throw switch box is dead, and is still not live!]

 

Yes, the dryer's fuses are in their own little box so that's certainly a possibilty. But we have plans to swap out the whole thing for breakers sometime in the next year. But anyway, I need to figure out the issue with how many amps are being drawn first, right? If its more than it should we'd just end up tripping breakers anyway, right?

 

You are getting into household wiring why not post question there, They are pretty sharp there and can answer your questions.

 

I may end up doing that. I'll probably have to enlist some help for doing electrical stuff.

 

Yes. And that is why I own an amp meter. I never assume stuff and always try replacing correct parts the first time, out of pride, even more than money reasons. You have to learn how to read it also. You have to put it in the right range (the lowest range ABOVE your anticipated draw is best, as you can more accurately tell the figure it gives)and read the number from that range. You also can only jaw clamp it around ONE wire - one individual wire - not the entire romex.

[To test individual appliances on *120* volt circuits and not the entire circuit, you have the choice of making sure everything else is off on that circuit and test that circuit's wire coming from the circuit breaker in your panel box -or- you can buy an appliance-type extension cord that has 3 visible ribs of wires in it (it's a flatter haavy duty short extension cord, that is tannish color) and carefully box-knife split down the ribs (making sure the insulation around each wire is still intact for your safety!), and then plug that extension cord in the outlet, then plug the appliance in the extension cord, then jaw clamp around ONE of the ribbed wires (hot or neutral). Then you can now test just that one appliance that is running (irregardless if other stuff is running on that circuit) to see what the draw of that appliance is (fan, tv., toaster, refrigerator, microwave, etc. - it is fun just to see.)]

Albeit, now they have a new tester for 120 circuits called a Kill-A-Watt - which is a watt/amp/volt meter - and you plug that in the wall, like a timer (they look just like one), and then plug the appliance in IT and it tells you. No extension cord necessary. These are an inexpensive meter and places like Harbor Freight sell them. Highly recommended.

But they do not test 240 volt circuits. For that you need the amp meter.