At least it came with the place and we didn't have to pay a cent for it.

It looks like Miele doesn't have a 30" built in.

What built in microwave do you guys have?

 

I use a Panasonic but that's a counter top. If your GE does not power up at all, it's probably a fuse or power supply. Both are easy to change.

 

Oh it powers up, it just doesn't nuke anything.

I love Chinese quality.

Anyway, will probably get the BOsch 800 or the Kitchenaid 2090sss. Miele is a joke, they don't even make 30" one.

I know with tight enough control, you can get decent quality. You'll just have workers keep jumping off the building, cough foxconn, cough. It must suck to work there, what with the most recent jump.

????? ???

 

Another amazing thread.

 

I personally feel that this question is too complex to just answer straight forward. Microwaves are incredibly interesting and a rather extensive and educational elaboration is therefore in order.

How a microwave oven works
The operation of a microwave oven is really very simple. It consists of two
parts: the controller and the microwave generator.

A schematic diagram of the microwave generating circuitry and portions of the
controller is usually glued to the inside of the cover.

The controller is what times the cooking by turning the microwave energy on
and off. Power level is determined by the ratio of on time to off time in a
10-30 second cycle.

The microwave generator takes AC line power. steps it up to a high voltage,
and applies this to a special type of vacuum tube called a magnetron - little
changed from its invention during World War II (for Radar).

There is no such thing as residual microwave radiation from a microwave oven - it is either being produced or is non-existent.



There is little energy storage in the microwave generator compared to the amount being used. The typical high voltage capacitor - the only component that can store energy - has a capacity of less than 15 W-s (Watt-seconds) even for the largest ovens. Power consumption is typically 800 to 1,500 W depending on oven size. Therefore, the capacitor will be fully drained in much less than .1 second - long before the beep has ended or the door has cleared the front panel. (Based on the numbers, above, for a 1,500 W oven with a capacitor storing 15 W-s, it is more like .01 seconds!)

WARNING: This only applies to a *working* microwave oven! If there is no
heat, the magnetron may not be drawing any current from the HV power supply and the HV capacitor can remain charged for a long time. In this case, there is a
very real risk of potentially lethal electrical shock even after several
minutes or more of being unplugged There *is* a wire mesh embedded in the glass panel. Since the holes in the mesh are much much smaller than the wavelength of the 2.45 GHz microwaves (about 5 inches or 12.5 cm), it is essentially opaque to microwaves and essentially all the energy is reflected back into the oven cavity.



Controller
The controller usually includes a microcomputer, though very inexpensive
units may simply have a mechanical timer (which ironically, is probably more
expensive
to manufacture!). The controller runs the digital clock and cook timer; sets
microwave power levels; runs the display; and in high performance ovens,
monitors
the moisture or temperature sensors.

Power level in most microwave ovens is set by pulse width control of the
microwave generator usually with a cycle that lasts 10-30 seconds. For example,
HIGH will be continuous on, MEDIUM may be 10 seconds on, 10 seconds off, and
LOW may be 5 seconds on, 15 seconds off. The power ratios are not quite linear
as there is a 1 to 3 second warmup period after microwave power is switched
on.

However, some models use finer control, even to the point of a continuous
range of power. These are typically "inverter" models which use a more
sophisticated
type of power supply than the simple high voltage transformer, capacitor,
rectifier, system described below. However, there have been some back in the
1970s that did this with a 1 second or so pulse width modulated cycle, fast
enough to have the same effect as continuous control for all practical purposes.



The operating voltages for the controller usually are derived from a stepdown
transformer. The controller activates the microwave generating circuitry using
either a relay or triac.

Sensors
More sophisticated ovens may include various sensors. Most common are probes
for temperature and moisture. A convection oven will include a temperature
sensor above the oven chamber.

Since these sensors are exposed to the food or its vapors, failures of the
sensor probes themselves are common.

Cooling fans
Since 30 to 50 percent of the power into a microwave oven is dissipated as
heat in the Magnetron, cooling is extremely important. Always inspect the
cooling
fan/motor for dust and dirt and lubricate if necessary. A couple of drops of
electric motor oil or 3-in-One will go a long way. If there are any belts,
inspect for deterioration and replace if necessary.

An oven that shuts off after a few minutes of operation could have a cooling
problem, a defective overtemperature thermostat, a bad magnetron, or is being
operated from very high AC line voltage increasing power to the oven.



One interesting note: Since 30 to 50 percent of the power goes out the vents
in the back as heat, a microwave oven is really only more efficient than
conventional
means such as a stovetop or gas or electric oven for heating small quantities
of anything. With a normal oven or stovetop, wasted energy goes into heating
the pot or oven, the air, and so on. However, this is relatively independent
of the quantity of food and may be considered to be a fixed overhead. Therefore,
there is a crossover point beyond which it is more efficient to use
conventional heat than high tech microwaves.

Microwave generator
This is the subsystem that converts AC line power into microwave energy. The
majority of microwave ovens use a brute force approach which consists of 5
parts: high voltage (HV) transformer running off the AC line, HV rectifier
diode, HV capacitor, magnetron, waveguide to oven chamber. (A few employ solid
state inverter in place of the simple HV transformer. These will be discussed
later.)

The most common microwave generator consists of the following:

* High Voltage Transformer. Typically has a secondary of around 2,000 VRMS at
0.5 to 1 amp - more or less depending on the power rating of the oven. There
will also be a low voltage winding for the Magnetron filament (3.3 V at 10 A
is typical).

You cannot miss this as it is the largest and heaviest component visible once
the cover is removed. There will be a pair of quick-connect terminals for
the AC input, a pair of leads for the Magnetron filament. and a single
connection for the HV output. The HV return will be fastened directly to the
transformer
frame and thus the chassis.

These transformers are designed with as little copper as possible. The
primary for 115 VAC is typically only 120 turns of thick wire - thus about 1
turn
per volt input and output (this is about 1/4th as many turns as in a "normal"
power transformer. (It's usually possible to count the primary turns by
examining
how it is wound - no disassembly required!) So there would be about 3 turns
for the magnetron filament and 2080 turns for the high voltage winding for
the transformer mentioned above. The reason they can get away with so few
turns is that it operates fully loaded about 90 percent of the time but is still
on the hairy edge of core saturation. The HV components are actually matched
to the HV transformer characteristics. Performance will suffer if the uF value
of a replacement HV capacitor is not close to that of the original.

There is also generally a "magnetic shunt" in the core of the transformer.
This provides some current limiting, possibly to compensate for various
magnetron
load conditions. However, it's not enough to provide any reduction in the
likelihood of electrocution should you come in contact with the HV winding!

* Rectifier - usually rated 12,000 to 15,000 PRV at around 0.5 amp. Most
commonly, this will be rectangular or cylindrical, about 0.5 inch long with wire
leads. Sometimes, it is a box bolted to the chassis. One end will be
electrically connected to the chassis.

* Capacitor - 0.65 to 1.2 uF at a working voltage of around 2,000 VAC. Note
that this use of 'working voltage' may be deceiving as the actual voltage on
the capacitor may exceed this value during operation. The capacitor is metal
cased with quick-connect terminals on top (one end). Always discharge the
capacitor as described below before touching anything inside once the cover
is removed.

* Magnetron - the microwave producing tube includes a heated filament
cathode, multiple resonant cavities with a pair of permanent ceramic ring
magnets
to force the electron beams into helical orbits, and output antenna. The
magnetron is most often box shaped with cooling fins in its midsection, the
filament/HV
connections on the bottom section, and the antenna (hidden by the waveguide)
on top. Sometimes, it is cylindrical in shape but this is less common. The
frequency of the microwaves is usually 2.45 GHz.



When salvaging parts from dead microwave ovens, save the HV components
(transformer, capacitor, and diode) as a group (assuming all are still good).
Then,
if a repair is needed to another oven it may be better to replace all 3 both
because this eliminates uncertainty if more than 1 part failed or is marginal,
and they will have been designed to have the best compatibility.

Repair or replace?
With small to medium size microwave ovens going for $60-100 it hardly makes
sense to spend $60 to have one repaired. Even full size microwave ovens with
full featured touchpanel can be had for under $200. Thus, replacement should
be considered seriously before sinking a large investment into an older oven.

However, if you can do the repair yourself, the equation changes dramatically
as your parts costs will be 1/2 to 1/4 of what a professional will charge
and of course your time is free. The educational aspects may also be
appealing. You will learn a lot in the process. Many problems can be solved
quickly
and inexpensively. Fixing an old microwave for the dorm room may just make
sense after all.

Installation and Preventive Maintenance

Microwave oven installation and use
To assure safety and convenient, follow these recommendations:

* Read your users manual from cover to cover especially if this is your first
microwave. What a concept! If nothing else, you may discover that your oven
has features you were not aware were even possible. In any case, there may be
requirements or suggestions that are specific to your model and will enable
you to get the most performance from your new microwave.

* Select a stand-alone unit rather than a built-in if possible. It will be
cheaper to buy, cheaper and easier to service, and possibly more reliable since
ventilation and adjacent heat producing appliances will not be as much of a
factor.

* Select a convenient location - easy access and not too high or too low.
This is particularly important if the door of the oven opens down instead of to
the left side (only a few models are built this way, however).

* Put the microwave oven on its own dedicated 3 wire grounded circuit.
Temporary use of a 3 to 2 prong adapter is acceptable only if the outlet box is
properly
grounded to begin with (BX, Romex, or conduit with ground) AND the adapter's
ground wire or terminal is securely attached to the outlet box ground screw.

Make sure the outlet is in good condition in either case. Check that the plug
(or adapter) fits tightly and that there is no appreciable heating of the
outlet during use of the microwave oven. If there is, spread the metal strips
of each of the prongs apart if possible and/or replace the outlet.

A grounded outlet is essential for safety. Microwave ovens are high power
devices and a separate circuit will eliminate nuisance fuse blowing or circuit
breaker tripping when multiple appliances are being used at the same time. It
will also minimize the possibility of Radio Frequency Interference (RFI)
between it and any electronic equipment which might be on the same circuit. A
GFCI is not needed as long as the outlet is properly grounded and may result
in nuisance tripping with some microwave ovens.

Inexpensice outlet testers are available at hardware stores, home centers,
and electrical parts distributors, to confirm that the outlet is properly wired
and grounded.



* Allow adequate ventilation - do not push it up against the wall or wedge it
under a tight fitting wall cabinet (or inside one for that matter!). Leave
at least 2 inches on all sides and top if possible.

* Do not let children use the microwave oven unless properly supervised. It
is very easy to cause a fire through the use of excessive times or power
settings.
Even something as simple as microwave popcorn can explode and/or catch fire
if heated for too long - e.g., 5 minutes instead of my precisely determined
3:41 on high :-).

Microwave oven maintenance
Most people do not do anything to maintain a microwave oven. While not much
is needed, regular cleaning at least will avoid potentially expensive repairs
in the future:

* Clean the interior of the oven chamber after use with a damp cloth and some
detergent if necessary. Built up food deposits can eventually carbonize
resulting
in sparks, arcs, heating, and damage to the mica waveguide cover and interior
paint - as well as potentially more serious damage to the magnetron. If there
is any chance of food deposits having made their way above the waveguide
cover in the roof of the chamber, remove the waveguide cover and thoroughly
clean
inside the waveguide as well.

* Clean the exterior of the cabinet and touchpad in a similar manner. DO NOT
use a spray where any can find its way inside through the door latch or
ventilation
holes, or a dripping wet cloth. Be especially careful around the area of the
touchpad since liquid can seep underneath resulting in unresponsive or stuck
buttons or erratic operation. Do not use strong solvents (though a bit of
isopropyl alcohol is fine if needed to remove sticky residue from unwanted
labels,
for example).

* Inspect the cord and plug for physical damage and to make sure the plug is
secure and tight in the outlet - particularly if the unit is installed inside
a cabinet (yes, I know it is difficult to get at but I warned you about
that!). Heat, especially from a combination microwave/convection oven or from
other
heat producing appliances can damage the plug and/or cord. If there is
evidence of overheating at the outlet itself, the outlet (and possibly the plug
as well) should be replaced.

* Periodically check for built up dust and dirt around the ventilation holes
or grills. Clean them up and use a vacuum cleaner to suck up loose dust. Keeping
the ventilation free will minimize the chance of overheating.

* Listen for any unusual sounds coming from inside the oven. While these
appliances are not exactly quiet, grinding, squealing, scraping, or other noises
- especially if they were not there when the oven was new - may indicate the
need for some more extensive maintenance like belt replacement or motor
lubrication.
Attending to these minor problems now may prevent major repairs in the future.

* Keep your kitchen clean. Yes, I know, this isn't exactly microwave specific
but cockroaches and other uninvited guests might just like to take up residence
inside the electronics bay of the oven on the nice warm controller circuit
board or its neighborhood and they aren't generally the tidiest folks in the
world.

If it is too late and you have a recurring problem of cockroaches getting
inside the electronics bay, tell them to get lost and then put window screen
over
the vents (or wherever they are entering). Such an open mesh should not
affect the cooling of the electronic components significantly. However, the mesh
will likely clog up more quickly than the original louvers so make sure it is
cleaned regularly. If possible, clean up whatever is attracting the unwanted
tenants (and anything they may have left behind including their eggs!!).

CAUTION: Do not spray anything into the holes where the door latch is
inserted or anywhere around the touchpad as this can result in internal short
circuits
and costly damage - or anywhere else inside, for that matter. If you do this
by accident, immediately unplug the oven and let it dry out for a day or two.


P.S. to answer your original question, I don't own a microwave oven.

 

Is your microwave marrying a whore?
If not I am not interested.

 

Are Miele's microwaves made in China?

 

From what I find on google they're only made in Germany, Czech Republic and Romania.

 

I have a Sharp its "semi built in" LOL.

 

Pretty sure IB didn't know it was actually buying TeamMicroWave.com