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Post by turbokinetic on Jun 21, 2018 2:33:42 GMT
New seal installed, viewed from the side.
Tomorrow's work, hopefully!
Compressor under vacuum. Hope it holds!
So the compressor is now fully cleaned of SO2 residue, resealed and ready to work again. I'm sure that leaks will be the hardest thing to keep at bay on this machine. It has so many places for leaks to happen. But, that's the nature of it. It is what it is and there are few of them left so I am willing to deal with its shortcomings to have it work again!
I have a video as well, but it is uploading slowly. Will make additional reply when it's ready!
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Post by turbokinetic on Jun 21, 2018 2:35:01 GMT
^^^^ Man now that's very interesting^^^^
Thanks! I agree it is fascinating. Video uploading and there are more details of the repairs and of the control mechanism.
This one got a little long but that is just because I'm so enthusiastic about the subject matter!
EDIT: I am sorry about the corrupted video I posted and had to remove. It's re-uploading and should be posted in the morning.
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Post by coldspaces on Jun 21, 2018 3:21:06 GMT
Amazing work in such a short time. I am in love with that control and am now jealous that I don't own one!! That is like nothing I have ever seen!
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Post by turbokinetic on Jun 21, 2018 3:23:55 GMT
Amazing work in such a short time. I am in love with that control and am now jealous that I don't own one!! That is like nothing I have ever seen! Thanks! I just like to finish things when I start them. Also wanted to get the SO2 residue out so that the compressor wouldn't corrode internally.
That control is definitely surprisingly intricate! But, really it is only different in that it uses the active refrigerant charge to do the sensing; instead of a bellows with a small isolated charge as with the General Electric controls.
They are out there, just getting fewer and farther in between. The hermetic motors came out in the 1930's with superior technology. That was such a game-changer that these started to die off faster than they might otherwise have.
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Post by ckfan on Jun 21, 2018 12:24:29 GMT
Bravo! Excellent work so far. I can’t believe you were able to adapt a modern seal so quickly! I really hope that it holds up for you. Very interesting to see the pistons with reed valves in them. So I guess as they go down the valve opens and lets in gas from the crankcase below?
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Post by turbokinetic on Jun 21, 2018 12:54:08 GMT
Bravo! Excellent work so far. I can’t believe you were able to adapt a modern seal so quickly! I really hope that it holds up for you. Very interesting to see the pistons with reed valves in them. So I guess as they go down the valve opens and lets in gas from the crankcase below?
Thanks! I really appreciate the positive responses on this project.
I have a feeling that the "common blood line" between the two compressors made the seal swap easier. As you know, the Harrison HR6 compressor (seal housing donor) evolved from the older Frigidaire A6 compressor used on the early air conditioned GM cars. The early ones of them came with a mechanical seal that failed all the time as well. The dual lip seal I used was a design that GM went to as they improved the design over the years. I am sure the seal its self will do well. My only concern is the seal between the aluminum seal housing and the compressor body. It is a tight fit and sealed with Permatex Right Stuff. That should do the job under the pressure conditions encountered. I am just hoping there's not a problem where the refrigerant swells or dissolves it. I don't expect it will be a problem - but haven't used this product for refrigerant before.
The video upload finished, and here's the link to that.
Hope to get on the motor today and get it up and going!
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Post by ckfan on Jun 21, 2018 16:36:50 GMT
Very interesting! I have one of those A6 compressors in my 78 Bonneville. It works great!
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Post by icebox on Jun 21, 2018 21:16:56 GMT
That is an industrial looking compressor unit to go with the industrial looking evaporator. Love it. I like the idea of the cold control using the low pressure side, has the advantage of stopping the compressor on low gas too. And I love the engineering - as you say in the video no CAD - amazing. Thanks for all the photos and the video. It's great to capture the history of this type of fridge that so many can now see. New shaft seal looks good - all looks promising!
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Post by coldspaces on Jun 22, 2018 2:08:07 GMT
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Post by turbokinetic on Jun 22, 2018 2:28:53 GMT
Very interesting! I have one of those A6 compressors in my 78 Bonneville. It works great! My 1972 Chevy Nova originally had an A6 compressor, but I eventually had to replace the engine. Used a newer model engine and that one has a V5 variable displacement compressor. The A6 did work well, though. That is an industrial looking compressor unit to go with the industrial looking evaporator. Love it. I like the idea of the cold control using the low pressure side, has the advantage of stopping the compressor on low gas too. And I love the engineering - as you say in the video no CAD - amazing. Thanks for all the photos and the video. It's great to capture the history of this type of fridge that so many can now see. New shaft seal looks good - all looks promising!
Thanks again! Yep the shaft seal seemed to hold well overnight. It had vacuum this morning, and I pressured it with inert gas. Then throughout the day there was no loss of gas pressure that I could see. Also put soap water all over it and didn't see any bubbles LOL!
Today was "motor day" so to speak. This fridge is so totally General Motors it almost could have been branded Chevrolet! The electrical parts of it are Delco-Remy, such as the fuse holder and the switch contact plate. The motor is Delco. I'm a diehard GM fan so this one has extra special meaning for me as well.
Unfortunately, the Delco motors have a somewhat troublesome start contact arrangement. This one was no exception. It appeared someone had tried to work on it in the past and parts were missing and mangled.
So, I got a Supco 3-in-1 kit and used it to replace the centrifugal mechanism. It works well! Just like with hermetic motors, the PTC start device does require a certain amount of time to recycle at each start. Otherwise it operates this motor just like it does a hermetic motor.
First, the fan has to come off. I see marks where a hammer-and-chisel mechanic worked on it!!!
Next, the motor stator wiring was in DEPLORABLE, HIDEOUS condition. There was no insulation on it. That is no bueno.
So, the totally missing wire was replaced, and the others were reinsulated with heat shrink.
The motor didn't have any sort of internal fan! That is not a good design at all. The condenser fan blows forward away from the motor so that wouldn't be enough. I feel as if this was a lesson learned after this motor was made and decided to take the liberty of installing an internal fan. This fan came from a sadly deceased Dayton motor. It moves a lot of air, in spite of the small openings in the Delco motor. I ran it for about 3 hours without the pulley or fan and it didn't get hot.
The Supco start kit capacitor and PTC relay device all fit inside the original capacitor housing. This will eliminate the need for a centrifugal switch.
(continued)
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Post by turbokinetic on Jun 22, 2018 2:33:18 GMT
The thermal overload breaker from the Supco start kit was attached to the new terminal board I made for the motor. Everything is internal and with the cover in place, you can't see it has been modified!
Compressor pump painted, after leak-checking. I left the brass and copper fittings bare since they look good like that, in my opinion!
Skid mostly back together.
Delco Motor nameplate cleaned up and clerarcoated.
Same for the Frigidaire nameplate.
(continued)
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Post by turbokinetic on Jun 22, 2018 2:54:06 GMT
The unit had a vee belt pulley on the motor, and a flat belt pulley on the compressor. I have seen one on YouTube with this configuration, but not sure if this is by design or it that was possible similarly modified... or if it was actually this unit before it was defunct! Either way, the clearance between the compressor skid and the flywheel rim was to small for the vee belt to fit there. I chose to change to a flat belt; or actually a vee-ribbed belt. just happened to have an old alternator pulley kicking around. It was actually from a Delco alternator... going onto a Delco motor. I just took the original pulley and turned it down until it was a press fit inside the alternator pulley. Then forced the new pulled over the turned-down original. There is perfect clearance for the flat belt between the skid frame and the flywheel, The condenser coil cleaned up nicely! Another view of the belt in place. This one is too long and I'll get a shorter one tomorrow. The irony is, this skid doesn't look old. Hard to believe it's almost 90 years old! I made a video of motor testing, and will post a link after it uploads. Hopefully it's not a malfunction experience like the one I tried to post last night! Will reply with that later.
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Post by turbokinetic on Jun 22, 2018 4:23:06 GMT
Here is a short video of motor testing.
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Post by birkie on Jun 22, 2018 10:37:54 GMT
Outstanding progress! Just thinking about the control. The fact that it uses the low-side pressure presents an interesting twist when using different refrigerants. So here are some pressures at a saturation temp of 10F: Refrigerant | psia | gague pressure | Absolute pressure from SO2 | SO2 | 13.3 | 2.7" vacuum | - | R124 | 14.5 | 0.3" vacuum | +9% | R134a | 26.62 | 11.9 | +100% | R236FA | 9.19 | 11.2" vacuum | -31% |
So I'm not entirely sure how to analyze this yet. R124 is pretty close - I'd be fairly confident that some minor adjustments would make it work. The R134a would need 2x the force opposing it for a given temp than the SO2. Atmosphere provides some of that, and various springs in the control provide the balance. The "bias" needed in order to balance out the additional 11.9 psi from R134a may be significant. It's hard to visualize in my head - but that control looks like it has so many different parameters that can be tweaked. I'm optimistic you'll find a way one way or another.
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Post by ckfan on Jun 22, 2018 12:01:15 GMT
I’m just blown away. This is beyond cool! I really like what you did to save the motor. I can’t believe it didn’t have an internal fan either. That should help the old windings hold up better. The supco 3 in 1 is a good idea since you didn’t have the parts for the start circuit. I’m also glad that the compressor seems to be holding pressure just fine. Thanks for leaving the bright work unpainted. Kind of reminds me of old engines from the turn of the last century which had all kinds of brass, copper, and nickel.
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