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©2006 All Rights Reserved
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In this issue:
Update: GFI Circuits Aren't Saving Tall Tub Dishwashers!
2) Refrigeration System Recharging Basics - Part 1
3) Send These Folks a Christmas Card - They Need
Back in the April '05 issue we discussed how Ground Fault
Interrupt (GFI) breakers and receptacles supplying power
to a dishwasher can catch pump seal leaks early, saving
money and floor damage.
But I've had to modify my
opinion on the subject now that
I'm starting to see rotary seal failure in newer 'Tall Tub'
pump/motor assemblies used in these
dishwashers allow leaking water to 'sneak' right past the
motor's windings, not tripping the GFI.
I've just posted an update
to the previous article, along
with a picture of yet another recently ruined Whirlpool
Tall Tub motor, at:
I've had quite a few folks ask if I could run through the
procedure of recharging a refrigeration system, so I'd like
to do an overview of the subject. We'll start with a few
basics in this issue, and continue the discussion over the
next few months as space allows. So let's jump right in
with some basics, and then the first (and most important)
First let me define what
we're talking about. The 'system'
refers to the motor/compressor, evaporator (cold) coil,
condenser (hot) coil, drier/filter, refrigerant, and connecting
tubing. These are the components that do the actual work
of moving heat from the inside of a refrigerator's cabinet
to the outside, or 'ambient'.
Note, technically, that
'cold' is not produced during
refrigeration, but heat is removed by the boiling of a
refrigerant from a high pressure liquid into a low pressure
vapor. We're just moving heat from one place to another.
As high-pressure liquid
refrigerant is 'pushed' from the
condenser coil up into the freezer's evaporator coil by the
compressor (basically an air pump), its pressure drops
suddenly as it enters the coil, causing it to boil rapidly into
Boiling refrigerant inside
the evaporator coil at subzero
temperatures F, it absorbs heat from the surroundings,
and the resultant vapor carries this 'latent' heat outside
the cabinet, where it is once more pressurized by the
compressor, which changes it back into a liquid to repeat
That's a simplified
description of the process, but covers
the basics. The hardest part to grasp is the idea that of
a liquid boiling at cold temperatures, but that's what a
refrigerant is engineered to do.
(Back in the 'old days',
we'd often amuse ourselves by
dumping a few ounces of R12 into a Styrofoam cup,
watching it sit in that Styrofoam and boil happily away,
chilling our fingers through the foam. A strange sight.)
There are basically 3
system problems we see in
refrigerator and freezer systems (and these days, my
recommendation with any of these 3 is nearly always the
same: scrap it). We see either a failed compressor,
refrigerant leak, or system restriction (clog).
It's important to note that
failure of other components
can make you suspect a system problem, but in the field,
most cooling complaints we handle are NOT related to
the system, but other failures, like defrost heaters,
defrost tstats, timers/ADC's, fan motors, etc.
So let's briefly talk again
about the built-in diagnostic
tool that every system has.
We discussed this in
March '03 issue
If a refrigerator is
‘running but not cooling’, or is 'cooling
poorly’, and everything seems to be clean and running
(clean condenser, fans and compressor running), our
turns to the sealed system.
So many times over the years
I’ve looked at a refrig that previous servicer has checked, and found an access
valve clamped to the suction line (and very often leaking!).
When questioned, the owner
usually says something like,
‘yes, he had to attach a set of gauges to check the system’,
and I always find it hard not to groan out loud. Folks, it’s
necessary to poke a hole into a refrigerator to find If a tech knows his business
out what’s going on inside it.
and is at all interested in being efficient, he’ll know this.
If the above conditions
describe your refrig or freezer, do
this: leave it running if you can, and remove whatever
are over the evaporator (cold) coil. If you see a nice,
frost pattern covering the entire coil, even if it’s 1”
you do NOT have a system problem. It’s just that
If only part of
the coil is frosted and the rest is bare or only
wet, you DO have a system problem - leak, restricted, or
compressor - and these days I usually recommend replacing
the refrig or freezer.
Here's a photo of a leaking
system's 'short' frost pattern:
Notice that the frost
appears only on the first few passes
of the evaporator coil. In a properly operating system, the
entire coil will be evenly coated with that white frost.
Next month: Part 2, System
leak testing and repairs
In closing, I'd like to recommend, again this year, that you
consider the following:
Please add one more address to your CHRISTmas Card List!
spend $.39 this CHRISTmas season to help make a point - please
do the same!
Wanna have some fun this CHRISTmas? Send the ACLU a
CHRISTmas CARD! As they are working so very hard to get rid
of the CHRISTmas part of this holiday, we should all send them
a nice, Christian, card to brighten up their dark, sad, little world.
Make sure it says "Merry CHRISTmas" on it.
Here's the address - just don't be rude or crude. (It's not the
125 Broad Street
New York, NY 10004
A couple of tons of CHRISTmas cards should slow operations
down a bit, because they won't know if any are regular mail
So please spend 39 cents and tell the ACLU to leave CHRISTmas
alone. You might also want to tell them, nicely, that there is no such
thing as a ‘Holiday Tree’, and that we’re getting really tired of their
‘politically correct’ baloney!
PS - Regarding 'political correctness': I'm not a
politician - I'm a
Christian, and CHRISTmas is my Holiday!
PPS - Next month I'll begin using a new system to
DRSNews. I'll be 'cleaning' our mailing list, as well, so you'll
probably get a request for 'opt-in' confirmation to make sure
you'd like to continue receiving this newsletter. This ensures
there are no subscribers receiving this in error. I don't want to
end up in inboxes where I'm not wanted ;-) !
Wishing the very best ever CHRISTmas to you and yours!
Dave’s Repair Service
New Albany, PA
Wise Men Still Seek Him.
www.DavesRepair.com , All Rights Reserved
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