Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Breville SHM2 kitchen mixer, probably 2008

Nothing working , neither motor, 1Meg across mains "on or off". No obvious
water ingress, nasty smells, or burning. 24 segment armature, .2mm wire , 25
to 27 ohm across brushes for 1 rev.
Beater motor opened up, bowl motor not seen. A thin multistrand wire with
yellow sleeving , loose inside with no obvious tag remnants to the motor.
The stator has yellow high temp tape around it and picking off part of the
last turn there is a broken wire with a lot of copper carbonate corrossion.
But this wire is .15mm which seems small for a presumed 380/2 W motor , 380W
m/c total. Some sort of sense wire ? and without it the , unseen, presumed
triac control inside the handle is disabled. I find it difficult to believe
..15mm wire would be actively in a mains motor stator even if it is for the
slowest setting. 8 exposed magnet wire ends around this stator of .4, .2 and
..15 mm diameters if the broken one is included. Even if repaired how to
avoid more water/condensation damage on such fine wire ?


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Default Breville SHM2 kitchen mixer, probably 2008

I think I've found where the yellow wire is broken from, it is the neutral
from the mains and is twisted to a grey wire before being soldered to a tag.
Desoldering it then it become obvious that what looked like the end of the
grey wire is the remnant multistrands of the yellow.. I'm only in delayed
contact with the owner. I suspect this wire broke on me removing the motor,
the 1M over the mains seems to be the R of a mains RC filter. There is 10
wire ends to the stator, down to .1mm which marries up to the remnant on a
tag. A .4 mm wire is soldered internally , under the yellow tape to a
probably .15mm wire that then presumably carries on to a tag with a remnant
..15 mm wire on it. Someone's idea of a fuse ? I've looked on one side of
this .4mm soldered end, under x30 and can see no sign of a break, will try
turning it to view the other side. I suspect these 5 stator wires in
parallel/series give the hi/low + boost and 1 to 5 speed ranges and no triac
control. Elsewise joining .4 to .15mm wire makes no sense. I suspect the
owner lost the .1mm low speed range some time back and then sometime the
..15mm wire broke and then the neutral connection .
I would have expected to only see .1mm wire in a mains clock motor not a
torquey motor.
The motor at the rotor pole pieces, so about 18mm radius, requires about 100
gram to turn, Compared to drill motors this seems a bit tight. I've not
removed the nylon gears yet to check but a bit of turning resistance might
have led to an overload of motor current


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Default Breville SHM2 kitchen mixer, probably 2008

Got it running on positions 2 to 5 low to full speed with right sort of
power draw off the mains , hi/lo works and boost works all up to full mains
but pos 1 has problems. I used a variac of course initially and pos 1 was
going in reverse at 30 percent mains, at full tilt as though on 5. At 50
percent mains for half a second, no motion, nasty buzz and mains draw of
over 1 amp. Where to go from here , I assume pos 1 is not reverse or it
would be marked R, what have I miswired ? Time to delve into the handle and
its switches


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Default Breville SHM2 kitchen mixer, probably 2008

On Dec 15, 6:37*am, "N_Cook" wrote:
Got it running on positions 2 to 5 low to full speed with *right sort of
power draw off the mains , hi/lo works and boost works all up to full mains
but pos 1 has problems. I used a variac of course initially and pos 1 was
going in reverse at 30 percent mains, at full tilt as though on 5. At 50
percent mains for half a second, no motion, nasty buzz and mains draw of
over 1 amp. Where to go from here , I assume pos 1 is not reverse or it
would be marked R, what have I miswired ? Time to delve into the handle and
its switches


Stamp an R over the 1 and call it quits.
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Default Breville SHM2 kitchen mixer, probably 2008

wrote in message
...
On Dec 15, 6:37 am, "N_Cook" wrote:
Got it running on positions 2 to 5 low to full speed with right sort of
power draw off the mains , hi/lo works and boost works all up to full

mains
but pos 1 has problems. I used a variac of course initially and pos 1 was
going in reverse at 30 percent mains, at full tilt as though on 5. At 50
percent mains for half a second, no motion, nasty buzz and mains draw of
over 1 amp. Where to go from here , I assume pos 1 is not reverse or it
would be marked R, what have I miswired ? Time to delve into the handle

and
its switches


Stamp an R over the 1 and call it quits.

++++
quits being a puff of smoke, disable the "1" linw when you know which it is
, maybe.
Getting inside the handle it all became obvious once you know which is the
low current, low speed lead when they are all the same size multistrand
gauge of wire going into the handle . Inside just a simple 1 to 6 pole sw
and 2x 2 position slide sw, then 2 off x2 yellow blocks, 2 blue disc ceramic
over the commutator and no electronics at all.




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Default Breville SHM2 kitchen mixer, probably 2008

Looks as though this is how it failed. Not made for mixing thick mixtures at
low speed as .1mm wire for the last run of that 1 setting and over time the
wire must have brittalised+corroded from excess load current and failed at
one end where the loose tails can vibrate, break and blow out through the
housing. Continued being used but without speed 1 and at some point the
second end must have broken away and blown out, leaving just 2 tiny remnant
bits at the solder points, easily overlooked, and other break ends under the
bulk of windings , so unseen. Then the neutral connection failed and no use
after that. Will try a diode in the 1 position linked to the 2 winding


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