On Monday, September 28, 2015 at 10:37:56 AM UTC-5, Stormin Mormon wrote:
On 9/28/2015 10:02 AM, trader_4 wrote:
A friend of mine had a Subzero 550 fridge/freezer that is about
20 years old.
CY: I've worked on several of htese.

It has separate compressors for the fridge and
freezer. The fridge side is no longer holding temperature.
Sometimes it's OK, other times the temperature rises.

CY: The fridge compressor is the smaller one. DAMHIKT.

He had
the Subzero dealer out to diagnose and they told him the compressor
is bad, should change that, evaporator, and convert from R12
to R134.

CY: The old hermetic compressors typically fail
all at once. This up and down temp doesn't sound
like a bad compressor. I'd first clean the condenser.


Bad news is they want $4K, which is a rip off. Looks
like they figure they can get it, since a new unit is $10K.

CY: Hope he gets kissed for that much money. And some chocolates.


The rest of it is fine. My first thought was, does it even need
a new compressor? Is that kind of behavior, holds temps most
of the time, goes up in temp other time even indicative of a
compressor failure? In my experience, they either work or they
go completely, never seen one intermittent.

CY: Sounds more like thermostat, or dirty condenser. Wish I was there,
to look over the situation.

My first thought
was maybe it's the thermostat, the compressor cap, fan, etc.
I had him check though and he says that when it's not holding
temp, the compressor and evaporator fan are running, so that
would seem to rule the other stuff out.

CY: Right, compressors usually go klunk and die all together.


So, I did some research online and the compressor is actually
made by Embraco, an EMI30ER1. I found it online, including
shipping for as low as $130. Looks like it's good practice
to replace the evaporator too, because that's a common failure.
Found an aftermarket supplier for that for $200. I guess that
R12 is still available and legal, but I guess given the
circumstances, better to convert to R134?

CY: If you get to the point of replace condenser, R409a is
a drop in replacement. R416b is a little cheaper, and also
works fine. I doubt you need it, though.


So, looks to me like a fair repair guy should do this for
~$500 in parts, $500 in labor = $1000? Does that sound
about right? He has another independent
type repair guy coming that he found from a neighbor who
recommended him to give another opinion. I suggested that
when the guy gets there he should let him make his diagnosis

CY: I'd tell the guy the symptoms, and let him (or her)
look the machine over.

and as soon as he says it needs a compressor, he should say,
"yeah, that's what Subzero said, it's an Embraeco and I see
it's available online for $150..... So they know you're
smarter than the average bear before he works up the quote.

CY: I hate price chiselers like that.


Any other thoughts?


CY: Clean the condenser. Wonder what was the operating
pressure while the system was running? Low side port
is usually available.
--
.

The last Subzero fridge I saw had a commercial type semi-hermetic compressor like you see in remote condensing units for restaurants and grocery stores. It makes them easy to diagnose and service. Those can be repaired or exchanged for rebuilt compressors. It's not a throw away compressor like in most residential refrigerators. They're also extremely tough and reliable units but they do need service every now and then. The last semi-hermetic R-12 system I did a retrofit on was a walk in cooler. It was moved to a new location and filled with R-416a which actually performs better than R-12. R-416a will be manufactured through 2020 so stock up on it while you can. If you remove all the R-12 from a leaking system, you can repair it and drop in R-416a without changing the oil. You don't mix it with R-12. ^_^

http://compressors.nationalcompresso...set/k-copy.jpg

http://airgasrefrigerants.com/userfi...16A-graph1.jpg

[8~{} Uncle Fridge Monster