Strange fridge compressor failure - Embraco...

[turbokinetic]

Here is a video I did a little while ago. This is an earlier Embraco 1/4 HP compressor from a Coke machine. This Coke machine was restored by a really poor quality shop and returned to the owner with a non-working compressor. The original compressor had been replaced with this Embraco in the 90's I assume. I say that because it is an R12 compressor. 

 

These compressors are very well built. They are known for lasting a long time and having very few problems. When I initially removed this one, I found it had open windings. The starting components appeared to have possibly been exposed to water, so I figured that could have had something to do with the failure.  

 

In this video, I take apart the compressor and find something I haven't seen before. 

 

These compressors are good replacements for failed vintage fridge compressors, because they still have a large oil volume in the sump; and therefore will not suffer from oil dilution caused by the larger refrigerant charges used in the earlier systems. 

 

Sincerely,

David

 

 

 

[thatwasherguy]

That’s officially the strangest thing I’ve seen today...

I would have never in a million years thought of the connector on the inside coming loose from the pins. Is it possible that it wasn’t installed all the way at the factory, and worked itself loose over the years? Thanks for another interesting and educational video! They’ve been quite inspirational for me.
Thatwasherguy.

 

[retro-man]

Another job done well. Great learning experience for you and also us. Thanks for sharing this. Always impressed with your knowledge and expertise with refrigeration. Could watch these videos all day.

Jon

 

[turbokinetic]

Thanks you guys for the kind replies! I also hadn't ever seen this failure before. It is possible it wasn't properly connected from the factory, but I think that a too-short cable was more likely the cause. After I reconnected it, I could make it partially disengage by bumping the compressor mechanism on its springs, away from the terminals. 

These hold up well and I am glad to be able to put this one back into service.

Sincerely,
David 

 

 

[combo52]

Amazing compressor, diagnosis and repair

It’s always need to see what you can do. David, it goes to show that anything is repairable with the right diagnosis in skills at fixing it.

I still have quite a few brand new R12 refrigerator compressors, there’s even a couple whirlpool rotaries I’d love to give these to you. I don’t know anybody else that will probably use them at this point. Let me know if you’re interested in having me save them. Otherwise they’ll probably just go for scrap metal

John

 

[rp2813]

David, it's satisfying to see a simple repair correct a problem that is almost always erroneously considered a lost cause by disinterested, so-called technicians who only know how to replace things they are so quick to declare un-fixable.  I'm also impressed with Embraco's quality product and thoughtful design. 

 

Thanks for sharing.

 

Ralph

 

[turbokinetic]

John, and Ralph; thanks for your kind comments!  

John, I am happy that you're saving some earlier compressor models.  We will chat privately about them soon. I appreciate your offer for sure. 

 

Sincerly,

David

 

[henene4]

Looking at this it might just be bad luck. Transporting the appliance that compressor was in in a wrong orientation or just somebody at assembly dropping it and instead of not using it just using it might cause something like that.

Embraco are still supplying a certain amount of compressors for BSH fridges.
Before I left earlier this month there was some motion in replacing them as main source with Jiaxipera and keeping them as second source.
As far as I understand we had very little issues with the Embraco ones.

I actually used Embraco as source of choice in my bachelors thesis.
Main reason is that they have an open, easy to search library of all of their compressors and their performance data.
Really interesting stuff, actually.

 

[turbokinetic]

Henrik; it is sure helpful when you can locate the data on a wide variety of  compressor models from one manufacturer. This can also help as a "jumping-off point" for finding specifications on other less-well documented models. If a cross-reference from an unknown model to a known Embraco model can be found, likely you can infer certain details about the unknown model. 

 

It's interesting that your previous employer is shifting from an old and well-known brand to Jiaxipira. I sure hope the longterm durability of their products proves to be favorable. Their use of aluminum magnet wire in the stator is concerning. I don't think Jiaxipira are the only company doing this, by the way.

 

Historically, engineers have tried aluminum wire in a variety of scenarios, but it has only proven reliable in a few specific applications. It seems difficulty is always encountered in transitioning from aluminum wire to terminals made of other metals. We see aluminum winding motors from the 80's every now and then. Of the ones which no longer work, they always have open windings but no sign of burning. It is as if the lead wires are no longer connected to the stator winding. 

 

I had to do some digging for info on a Jiaxipira compressor and came up with very little info. This was ordered for a specific project and arrived with the plugs out and the oil spilled out into the packaging. I tried to locate the oil specification and amount, and came up with nothing. They were proud of their aluminum winding design but had no usable info whatsoever that I could find. I reached out to distributors and their technical e-mail as well, and got no reply.

 

It's not surprising that BSH has little trouble with Embraco. Of the failed ones I have seen, they had generally been damaged by external factors. Bear in mind almost all of what I work on are 1/4 and 1/3 HP medium temp drink coolers; so I have a narrow focus. Of those models, the most common failure has been shorted / grounded stator windings. These were associated with failure of the electromechanical start relay. There may be an edge case involved with the 1/3 HP capacitor-start models. It seems that if the start relay gets stuck in start mode, the stator winding will be damaged before the overload trips. I am sure that Embraco tested this scenario during the design phase. More than likely, as component values shift over time, things drift out of favor of the overload saving the winding. 

 

Sincerely,

David

 

[henene4]

Given that Jiaxipera is a Chinese supplier, it's kinda hard to find anything useful with just English and German googling unless you have specific models of compressors.

But if you order a few hundred thousand compressors a year, that's an entirely different story.
Sourcing basically went "We need a (cheaper) drop in replacement for this compressor and inverter combo" and they went "Here you go".
Same then goes for requirements of longevity and failure rate of course.

I do think that industrial and home sectors are entirely different beasts when it comes to compressor ratings and layouts.

The aluminium conductor issue has been known to be a problem in certain applications, yes.
But as far as I understand, as long as an inverter is involved, the higher detail of supervision those grant over the situation appears to mitigate some of the operational issues.
That's why many inverter motors now use aluminium wire, be it in compressors, appliance motors or even induction coils in cooking.

That however relies on certain manufacturing standards to be met - and that's more often than not hard to supervise really.

It's a give and take and especially refrigeration has become a much more price sensitive market in the past few years.

 

[combo52]

Aluminum windings in motors and compressors

Washer and the clothes dryer motors in the US since the late 60s have all had aluminum windings and they seem to hold up pretty well generally.

With the move to higher efficiency motors in more advanced top load in front load washers there’s more copper windings in them, The very few compressors that I have cut open, generally had copper windings, but I’m not surprised they’ll go to aluminum, copper prices are very high worldwide and there’s going to be a lot of pressure to go to aluminum wiring wherever possible.

 

[cfz2882]

A couple years ago,I was given a 2020 WP fridge that has a seized Jiaxpera compresser-tried a couple methods to try to get it running,but it is seized good.Fridge is in storage as in great condition and I may fix later when a suitable salvaged compresser appears(new compressers are plenty cheap too)