Washing Machine QRM

[HUGH]

We bought a new washing machine to replace the old, tired one on which the drum bearing was "knackered" as we say over here. This had a belt drive and a brush motor with multiple field windings enabling a simple ac controller to stop, start and change speed.

I thought it a good idea to buy a machine with a direct drum drive so there is no belt and the 3-phase motor runs the drum shaft directly. If I'd thought further I might have stuck with the old-fashioned arrangement. Having a 3-phase motor and an inverter-drive for the motor means the manufacturer can utilise off-the-shelf components but the question of EMC I never considered. This motor drive may have an industrial specification because it sends interference up the mains supply in much the same manner as an industrial drive I have in the workshop next to the shack running a 3-phase drill.

I will be trying a single-phase filter I happen to have acquired on the input to the thing soon but it's fortunate that the XYL doesn't use the machine every day!

[NQ6U]

What I find to be the most interesting thing about your post, Hugh, is that you have three-phase power running into a residential building. That's not typically done over here. In fact, given the age of my house (63 years), I consider myself lucky to have both 240VAC and actual three-prong grounded outlets available in the shack.

[PA5COR]

We have 5 groups 16 amp 230V 50 Hz.
In the mains there are already another 230V groups, not connected but if i want to cook electric there are just a few wires to pull to the cooker.
Having his professsional stuff in tthe workshop that would be easy to get the 3 phase in the house.

[K7SGJ]

Sell the thing. Get her a new rock for Christmas to beat the clothes with down at the stream.



ETA You might want to stay out of throwing distance.

[HUGH]

What I find to be the most interesting thing about your post, Hugh, is that you have three-phase power running into a residential building. That's not typically done over here. In fact, given the age of my house (63 years), I consider myself lucky to have both 240VAC and actual three-prong grounded outlets available in the shack.

I didn't fully explain that domestic incoming is normally only single-phase 240V at up to 100A and the 3-phase machinery has motor drives which convert the incoming to dc and then switch it sequentially with thyristors or IGBTs, resulting in a 3-phase putput. Because these motors and drives are "off-the-shelf" devices it keeps the cost down and 3-phase motors are easy to start and control.

These motor drives switch at between 3kHz and 12kHz with a generous range of harmonics to delight the radio user. Aaaargh!

(My 3-phase drill is another story, it cost $20 equivalent and weighs about 400lbs! Can't resist a bargain.)

[HUGH]

[QUOTE=K7SGJ;391718]Sell the thing. Get her a new rock for Christmas to beat the clothes with down at the stream.

Grandma had something equivalent. Not being near a stream it involved a washboard in a large earthenware sink and a quantity of blue dye in a bag.

http://www.rattlebrained.org/images/84.jpg

http://www.cultureshock.org.uk/inc/img.php/tpl/uploads/G12120-dooly-blue-bag.jpg/360/1/fill

Thanks for the warning....."Well you can do it yourself then!"

[W1GUH]

Sell the thing. Get her a new rock for Christmas to beat the clothes with down at the stream.



ETA You might want to stay out of throwing distance.

Even better would be a big rock for her finger!

[K7SGJ]

Even better would be a big rock for her finger!

I would imagine the wrong kind of rock would get the wrong finger.

[HUGH]

4957

That's the way to do it....only QRM from the XYL.

[kb2vxa]

Go for the washboard. Then add a one string washtub bass (you'll need it with the washboard anyway) and a few jugs of various sizes. You can make a few bob on the side with your New English Hillbilly Jug Band if you feel so inclined, guitar and banjo optional.

Good luck with that mains filter, that should knock it down a bit.

[K7SGJ]

Go for the washboard. Then add a one string washtub bass (you'll need it with the washboard anyway) and a few jugs of various sizes. You can make a few bob on the side with your New English Hillbilly Jug Band if you feel so inclined, guitar and banjo optional.

Good luck with that mains filter, that should knock it down a bit.


Heh, heh, heh, he said jugs. :bbh: