DIY Clothes Dryer Repair - Blown Fuse

Hi Floram, I'm not familiar with the dryer model you mention, but perhaps I can point you in the right direction, with some general comments until someone with more knowledge of the dryer can add a comment, i.e. the following is what I would do presented with the same fault. I am not sure if you are confident working on electrical plant, and using a multi-meter - you don't say in your post. It is vital that if you are not, you leave any fault finding to a qualified electrician, as electrics can kill!!

1. Switch off all the power to the dryer, pull out all the fuses, and ensure that no one can restore the power to the dryer from a remote location without your knowledge - if necessary lock the fuse box, and leave a large notice on it!

2. Disconnect the wires at both sides of the heating element(s), and check the heating element to dryer casing electrical resistance. It should be at least 1 Megohm - preferably more. Any less - replace the heating element. Check the electrical resistance of the heating element - it should be at least 3.3 Ohms, but I would expect it to be in excess of 25 Ohms. There should not be a short circuit (0 Ohms) across the heater.

3. Remove the drive belt from the motor. Spin the motor pulley by hand in the direction of normal rotation. It should spin freely. Listen for any clicking or rasping noises from the motor that would indicate brush problems. With the motor pulley stationary, grasp it firmly, and try and rock it from side to side against the motor casing. There should be no play or movement. A stiffness in the pulley when turning, together with play against the motor casing indicates motor bearing problems.

3. Try turning the dryer drum by hand with the belt off. If it doesn't turn freely, or there is a roughness, then suspect the dryer drum bearings.

With the symptoms you have described, and assuming that the dryer motor is AC, and is fitted with brushes, then my money would be on an internal motor fault. Most likely to be brushes worn down so much that arcing has burnt out or damaged part of the motor armature. As usual, I stand to be corrected!

You may burn your house down--Buy a new or used dryer--They are cheap compared to a fire. You could replace every electrical component on the thing and still have a bad bearing or something hung up causing a locked rotor.

Considering the time and money and risk of repairing the dryer to no avail, it would be a good time to get rid of it--I have given a couple perfectly good dryers away in the past few years--I wish I could give you one and save you any harm.

Please be careful--K T

Thanks Kilgore,

Advise well taken. It is time to change it, agreed. However, it has become more of a challenge. I did not wont to beaten by a lousy dryer, but I think it has.

No offence meant towards your skills--Motors and devices fail for reasons--Replacing the failed component may be rewarding, but finding out why it failed should be paramount before it is reconnected to a power source. Blowing fuses and burning insulation just makes the hair on the back of my neck stand on end--I would hate to hear about one of my friends here loosing a house, or worse. We push the envelope at work all the time when it comes to this(as long as no one stands a chance to get hurt), but not at home where we have to sleep!

Come to think of it--My youngest son, while I was holding him, grabbed the three speed switch for the ceiling fan in the kitchen and disemboweled it--I opened it and replaced it with a rated on/off chain switch and wired up the slowest speed. I will not leave for work with it on(ever) when my beautiful wife and precious kids are asleep upstairs. The transformer hums louder than I like--I bought a replacement for the original switch and I will be putting it in this week because of this thread---We should be extra careful at home! Thank you for jogging my memory, I owe you one!--K T

P.S. My wife caught our house on fire with a clothes dryer once--A packrat stuffed the vent hose full with a nest and it almost burned down the house--I came home to fire trucks everywhere and my clean clothes were smoldering out in the back yard--We were lucky and had a new dryer the next day.

Thanks halibutA, good comments.

I will measure the resistance as you suggested. I wonder if the heating element can just simply pull too much power? Based on the wiring diagram the cycling thermostat should interrupt if the air gets too hot.

I've removed the drum and belt, checked the motor and drum bearings, all is fine. Next time I open it I will do that motor check for clicking or rasping noises. You think it could be the motor brushes that are worn down? Could be. It is just strange that the fuse for the heating element blows, not that of the motor. However, L1 (line 1) is also ending up on the motor terminals which could indicate a fault with the motor after all. Will check that. I am a mechanical guy and only a limited E-fellow.

Yes the Motor is AC. Does it must have brushes? I will look for them and see.

Thanks.

Hi Floram, Your heater element can fail in a number of ways. Firstly, if your dryer is a commercial or industrial model, the heating element may consist of a finned tube, with the actual electric element inside the tube, and can be quite robust. Unfortunately, if your dryer is a domestic model, the element may not be as robust, and may simply consist of thin turns or coils of resistance wire around a fireproof card former. Obviously, the latter is more prone to damage, but you can actually look at it and see the damage. If the element fails open circuit, the electrical element physically breaks, and will pass no electrical current. You will then get no heating at all.

The element may break, or distort due to the actions of heat, and if not adequately supported as in some domestic models, the broken end of the element may spring back, and touch the element housing, or frame of the dryer. In this case, the dryer would draw excessive electrical current, and blow the fuse.

These are the simple heater faults. More complex element faults can appear - the heater element may be intact, but not be properly supported, and, as it heats up, it may distort and touch the casing, causing the fuse to blow. If you have a tube type element, the internal insulating medium between the actual electrical element and the tube may have broken down, or become damp, thus allowing some of the elecric current to flow to the casing or earth. Finally, the insulating element supports may have become burnt and carbonised over a period of time, loosing their insulating properties, allowing a path for the current to flow down to earth, and, again drawing too much current and blowing the fuses.

With the dryer completely isolated and disconnected from the electrical supply, you may be able to open up the heater, and look for signs of burning, or damage, but I agree with the other contributors that you can only play safe, and replace the dryer altogether, while at the same time, checking the fusebox and supply socket wiring. It is just not worth risking life, limb or property chasing the fault!

Thank you. Great list of what can go wrong with the heating element. It is a domestic dryer.

The heater is a rather heavy gage coil ~ 1 mm thick wound to about 8 - 9 mm coil OD where the coil is supported by about 18 ceramic ferrules which in turn are attached to small spacer arms extending towards the inside from a thin sheet metal tube of about 150 mm (6") diameter. The ~ 12" long tube is formed from two half circles bolted together.

Thanks lad. (I think lad is an amicable distinction in Scotland?)

I am not familiar with your dryer but in your post you say you "opened the plastic box on top of the motor where there are a few contacts by Bi-metal elements. They were all black and singed." Is this the motor that turns the clothes drum or the cycle timer motor?

If it is the timer motor then the contacts are probably pitted and they are overheating from the resistance and welding themselves shut. A sure recipe for a fire.

If it is the drum motor then the contacts are probably the start switch. If they are pitted then they not be making after a couple loads and not supplying the start windings. Thus no rotation and overcurrent through the main windings which blows the fuse.

On the other hand you say that L2 supplies the motor but the L1 fuse is blowing which makes me think it's a short in the heating element or timer.

Good Luck and please be careful, there is almost certainly 220 Volts from L1 to L2.

Gordie.

As always, my advice is given 'as is' and used at the full risk and responsibility of the user.

Hello Gordie,

Yes it is the drum motor I was taking about. I had the timer open as well and adjusted these contacts, they are fine, and you are correct, the contacts on this drive motor are the starter contacts which include a centrifugal switch.

However, all of that works fine. The motor starts properly. It is just that the fuse blows quickly. New fuse, all works fine, until the 30 A fuse burns out. Usually in less than 3 - 5 Minutes.

I will check for the brushes as suggest earlier.

Try checking the wire connection on the fuse block, loose connection can create heat and cause the fuse to blow. It will be noticed by burnt wires sometimes.

Ken Salt Lake City

Thank you Guest,

Good thought, I should check that too. As I had mentioned, there was "electrical smoke" everywhere the first time the fuse blew.