Log in

View Full Version : Dryer works in one direction


rissole
Mar 4, 2007, 06:39 PM
Hi,

I have a Creda white night tumble dryer CL 437 WV, the timer is broken and doesn't count down. So I have been using an external mains timer to use the dryer. The timer costs about £60 to replace.

Switching it on, the drier may start tumble drying in either rotation, i.e. clockwise or anti-clockwise. Anti-clockwise doesn't work, the blower doesn't get enough air through the drum, maybe the thermostat overheats and cuts off power to the heating elements, I don't know why but, anyway, the drum doesn't get very warm, and the exit has hardly any air pressure.

In a clockwise direction the blower pushes significant air through the drum, and the heater elements work normally, the clothes dry OK.

My question is, what dictates the direction of rotation? I expect it is a timer function, but how do I overide it so that the dryer always rotates in a particular direction? How does the drum reverse direction, what signal where is polarised? At the moment it is down to luck which way the drum starts turning on start up, and which way the drum keeps turning. Messing with the non-operative timer will sometimes change the direction after a minute or two, but not in any clear and repeatable way. I would like to be able to force it to work in a particular direction, or to be able to toggle the direction reliably. Circuit diagram, or just how it operates would be very useful. Many thanks.


Regards

Russell Mc Donnell. :confused:

stew_1962
Mar 4, 2007, 07:42 PM
Interesting. Motors have start windings in them to make them begin to rotate. Energizing the start windings is accomplished in several ways, depending on the motor itself. I'm sure there is a logical explanation to your backwards motor - try the electrical section for some guidance, just mention exactly what you've said here.

By the way, if the motor is turning backwards, the fan is blowing IN... and will cause it to overheat, as you've noted. Fortunately, the thermostat is doing what it is supposed to do when it overheats in there.

I'd shell out the Euros and get the timer, once you've determined the motor isn't faulty... I'm sure it would cost a few um, pounds?

Cheers,
Stew

rissole
Mar 5, 2007, 03:22 PM
Interesting. Motors have start windings in them to make them begin to rotate. Energizing the start windings is accomplished in several ways, depending on the motor itself. I'm sure there is a logical explanation to your backwards motor - try the electrical section for some guidance, just mention exactly what you've said here.

By the way, if the motor is turning backwards, the fan is blowing IN...and will cause it to overheat, as you've noted. Fortunately, the thermostat is doing what it is supposed to do when it overheats in there.

I'd shell out the Euros and get the timer, once you've determined the motor isn't faulty.... I'm sure it would cost a few um, pounds?

Cheers,
Stew

Hi Stew,

That sounds very informative. The dryer is supposed to occasionally go in the opposite direction for a limited period for a couple of minutes or so to avoid creasing, but should turn in the correct direction about 95% of the time. So it sounds like the motor is likely to have two live terminals and one neutral, unless there is a another live that just keeps it running in whatever direction it is already going. Makes sense to me that by monitoring what the terminal voltages are on the motor I should be able to work out what's happening, and prevent it from rotating in "the wrong direction." Hopefully the feeds to the heating elements are completely separate and will keep working as usual.

I don't really know my way around this site yet but I'll go looking for the electrical section. Thanks.

Cheers
Rissole.

stew_1962
Mar 5, 2007, 08:28 PM
I don't usually send people elsewhere, but you being in Europe, you'll likely get some better help on a site over there. I've looked around and you might try how to mend it .com - Find out how to mend just about anything (http://www.howtomendit.com).

It should be obvious that the European dryers work a little differently than what I'm used to working on... :).

Hop that lead helps get you closer to your solution.

Cheers,
Stew