General Electric CA Monitor Top Refrigerator - Seized compressor re-start attempts...

[turbokinetic]

So, this top assembly from a 19323 General Electric CA Monitor Top fridge came from the scrap yard. It was seized and had all its useful parts stripped.

 

The General Electric CA model was used only in 1933 and 1934. They used a very low pressure refrigerant which was only ever used in these two years of Monitor Top. This Methyl Formate refrigerant will degrade with time and heat, releasing non-condensable gases into the system. This requires maintenance  bleeding of the system.

 

The low pressure characteristic of this refrigerant meant that the compressor had a large displacement. The large size of the moving parts, compared to the small motor power means these will become "stalled," "stuck," or "seized up" very easily. This often happens from sitting, lack of bleeding non condensable gases, or from loss of the crankcase oil heater.

 

This is a hermetic motor compressor with the unit welded into a steel casing. The only access to the compressor is vie electrical connections to the motor's terminals.

 

In this video, I try increasingly forceful attempts to re-start the seized compressor.

 



 

 

 

[rp2813]

David, I may not understand the electrical theory behind this successful revival, but I admire your level of confidence in old machinery that was built to last. 

 

We need more people like you who can bring to life what most would consider lost causes, but I'm pretty sure you're one of a kind!

 

I hope this beauty finds a nice cabinet to sit atop once you've finished working your magic!

 

Ralph

 

[toploader55]

It always gets better.

I am constantly waiting for updates and New Threads from you Sir.

Your threads are a breath of Fresh Air for this club. So glad you are here. I truly believe hardly anyone would ever attempt these restorations seeing machines sitting in a Scrap Yard.

I anxiously await to see what happens next : )

 

[ozzie908]

@turbokinetic

David I would gladly pay to spend a week with you watching and learning .....

You are an inspiration I wish I could do what you do as your skills at bringing these Wonderfull old machines back to life is just amazing.

Thank you so much for allowing us into your world of how things are fixed.

Austin

 

[spacepig]

I love seeing these being revived for continued use! I really need to get mine up there and let you work your magic! Jeannine[this post was last edited: 11/12/2018-14:54]

 

[twintubdexter]

turbokienitic...

<span style="font-size: 14pt; color: #008000;">You certainly didn't go to school just to eat your lunch!</span>

 

[turbokinetic]

Thanks so much for the positive feedback on my projects here. Makes it easier to justify spending the time to participate!

 

twindubdexter; LOL I was never very good at school.... I was always daydreaming about tinkering with motors and mower engines and old junk to play with after school! I've always had a fascination with technical things and when I was a kid, air conditioning and refrigeration was a sort of "black magic" that very few understood and even fewer could work with. That's one of the reasons I was drawn to it.

 

So, I continued tinkering with the CA this morning and I believe I found the root cause of the seizure of the compressor.

 

The system had its service port soldered shut; which would preclude releasing the noncondensable gases from the system. It had massive pressure built up in it. A second possible contributing factor would be the lack of a crankcase oil heater. That was burned out. These heaters often fail while in storage, so I can't say for sure that was failed at the time the unit stopped working.

 

Here is some video from this testing:

 

The meter readings are power of 161 watts; down from 400 or more when I stopped it last night. The other is motor current which is also way down from where it was.

 

The port with the clear hose and oil is the bubbles of NCG coming out. It took half an hour or so to bleed off!

 

 

[retro-man]

I am so enjoying your videos and explanations of your work. I am amazed at what you pick up as junk and actually get it working again. True testament to how things were made years ago. Run them till they die, then just a little TLC by you and they are back up and running. There is another member here who has a monitor top and it works, but the cabinet along the top and sides get so hot that you cannot touch it for very long. Any idea what the problem may be? Sorry do not know the year or model #.

Jon

 

[retro-man]

I am so enjoying your videos of your work. Amazing you can pick up something as "junk" and a little TLC you get it working again. True testament of manufacturing back in the day. Run them till they die, and yet they come back to life with your knowledge. Another member here has a monitor top and it runs, not sure how cold it gets, but the top and the upper sides of the cabinet get so hot that your not able to touch it for more than a moment. Any idea what may be causing this? Sorry don't know the year or the model #.

Jon

 

[turbokinetic]

Hi Jon! 

 

The CK Monitor Top has condenser tubing in the round "drum" on top, and in the top deck surface of the cooling unit (the flat part that covers the top of the cabinet.) These tubes will get hot within seconds of turning on the compressor, if the system is healthy. When the unit has first been turned on, after the whole thing is at room temperature, the condenser tubes will get really warm, almost too hot to touch actually. Once the unit has cooled down and started cycling off and on, the heat will be much less.

 

However, I believe he probably has a CG Globe Top since you say the "top and sides" get hot.  The CG Globe Top has the condenser tubes in the actual "side surfaces" of the cabinet top, as well as the top deck area.  There is an area of what looks like "decorative ridges" around the top of the CG cabinet which are the condenser tubes. There is less surface area to dissipate the heat with this design (compared to the CK with drum-style condenser) so these seem to get hotter. I don't own a CG and I'm going on what others have said on that - just letting you know. 

 

To know if this is actually a problem, we would need to know the motor power demand; how cold the evaporator gets, and if it is able to cool down and cycle off. My CK condenser gets almost too hot to touch after an ambient temperature startup; but once it runs a while it's not that hot. If he's getting scared of it and turning it off prematurely, it may be that it's not getting time to stabilize.

 

 

[toploader55]

Good Lord...

Just Brilliant. And to think you didn't add anymore refrigerant ?

I think my next fridge will be a Monitor Top or a seriously Vintage one.

Bravo !!!

 

[turbokinetic]

Toploader55; Thanks for the comment!  Yeah, it still appears to have a charge in it, at the proper level. The refrigerant is methyl formate which is extremely frustrating to obtain. It is not a controlled substance, and not even a licensed refrigerant. The problem is there is only one supplier in the country. No matter which distributor sells it to you, it comes from the same suppler. They refuse to ship it to anything other than a registered commercial address. I have as of yet been unable to successfully receive a shipment of it.

I love the Monitor Tops. The best one is the 1935 or newer CK type. These have a Scotch-Yoke compressor and come from the factory with sulphur dioxide. These will work with most modern refrigerants without any modifications, and they usually are still functional. That's the one to go with if you are just starting out with the antique fridges.  

 

[robbinsandmyers]

Thats so awesome you were able to save it. I have two I use. A 1935 and a 1936 which is my daily. Both are CK machines but use sulpher dioxide. Do these produce the non conpressable gasses also that need bleeding or just the methyl formate machines?

 

[turbokinetic]

Hi, robbinsandmyers; thankfully only the CA methyl formate machines produce noncondensable gases. The other refrigerants do not break down chemically in the way MF does.

 

However; SO2 (sulphur dioxide) does have its own set of major drawbacks. It runs in a vacuum on the low pressure side of the system. It becomes violently corrosive in the presence of water. Therefore if there are any leaks, no matter how miniscule, the system will draw in air and moisture while running. The air will result in noncondensable gases; and the moisture will result in corrosion.

 

I'm not trying to say it's all doom and gloom. Just be vigilant for any signs of trouble and address them ASAP.  Another very good aspect of the CK machines is that they are not "married to" the SO2 refrigerant and there are modern, noncorrosive, non-irritant, inexpensive refrigerants which work in them, without any modifications. So; if a leak happens, you correct it, recharge, and keep going in better shape than before.

 

[supersuds]

This restoration makes me hope that you'll be able to get your hands on one of those Grunow refrigerators with methylene chloride refrigerant, that operates in a vacuum on both the low and high sides, but I suppose there are only a handful of them out thee.

 

[turbokinetic]

I would love to get a Grunow to fix up. Thankfully methylene chloride is not hard to get like MF is. It is, however, very aggressive and would require special materials to re-seal the compressor.

 

I believe early Carrier A/C also used methylene chloride, under the brand name "Carrene."

 

[eronie]

This is so interesting .

 

[turbokinetic]

Hi Eronie. I agree, these are fascinating. I love the technologies that were tried, marketed, and walked away from before things were "standardized" as they were.

 

[norgeway]

What was the refrigerant

That eventually was blamed on the big nightclub fire in Boston in 1942,I think it was Methyl Chloride but I may be wrong,,