Well then, I guess I will find out for myself what will happen! I will snag the modern screen and gasket when I can, but here is a more pressing question: The electrical portion of this machine.

If I switch to 110V I will need to purchase a new switch. I will run though my analysis of the original circuit and compare it to what I need for the new one and see if it makes sense or not. If I am doubtful I will get an electrician's opinion on the matter as well.



The original circuit, starting from the plug, uses four wires: Ground (green/yellow), Black (Phase 1), Blue (Phase 2), and Brown (Phase 3). However, Blue and Black are on the same line, so one can be considered a Neutral Phase. Going into the switch Blue and Black will separate into their own poles. The switch itself is a 3-pole + ground switch with a 500V 16A rating. Going from the switch, Black and Blue will run into the pressurestat while Brown will connect directly to the heating elements. Black will then run from the Pstat to one terminal of the heating elements and Blue will run to the end. If I simplified this correctly, this is an unbalanced Wye circuit, which is not a true 3-phase and allows the machine to run on 220V.


To fulfil 110V single phase, I would need a 2-pole switch w/ground (3 pole if the ground is not included) that is able to run 20A. As a single phase, I simply need to wire the Hot and Neutral in series with the Pstat and 2kW heating element. This would make it easier for me to wire the circuit and I would not require a transformer for the machine. I think I am correct on this but everybody makes mistakes. Hence why I will likely check with the electrician on this as well.

Many commercial espresso machines can be easily changed between single and 3 phase power. Yours is currently wired internally for 3 phase and jumping the blue and black likely should have been done internally as jumping them wired it for single phase but it's not obvious what's going on till you draw it all out. If you wire it for 110 you need a switch and wire that can carry the required current. And that depends on the elements you come up with. If you plug it in a 20 amp outlet, you should probably wire up the elements with 12ga wire. Given the short distance you might get a way with 14ga, but considering you need so little wire, I might even consider 10ga if the contacts are big enough to handle it. Big wire both heats up less and acts as a heat sink pulling heat out of the connectors which should keep them happier.

Ira

Yea I was going with 12AWG in my initial assessment but I will not make a decision yet. I intend to use this heating element supplied by cafeparts. It is a little pricey but it is actually in stock and I would have spent $100+ on a step up transformer anyways if I stuck with 220V. Since I am using one heating element, one of the original 220V elements will be stuck in the other heating element hole to plug it up but not be wired. The Bremas 25A 2-pole switch is my presumed selection unless told otherwise.

I used my original switch and it is working fine. The contacts in that switch are huge and should handle 2X the 220 current just fine.

That would be useful to know. One thing I was thinking when looking at the new switches was whether the square peg to fit the knob would fit on the old style one or if it would be too short! I guess I would be using less than double of the original 220V current if I converted to 110V and used a smaller total wattage. I would just not use one of the poles then to make it one phase, but I would still definitely need to replace the internal wiring to modern stuff and a bigger gauge.

This stuff is the wire I use. This stuff is small overall diameter and highly flexible. Many fine strands provides a higher current capacity than the usual stuff. You can use crimp on connectors as long as you also solder them. https://www.mcmaster.com/catalog/125/862 Be sure to look at the ratings.

I replaced all wiring in my 62 machine including the power cable and when I wired the 120-240 transformer I used this space saver wire because the junction box is rather small.

Interesting to note! I will be using a modern switch cover as the original one housing the switch was too brittle and cracked, breaking when I unscrewed the screws holding it to the frame.

I am still cleaning away coffee gunk from various parts. The ultrasonic cleaner and Joe-Glo work well together.



Cleaning the Mercury Pstat and How it Works
I was always excited to get to this, which was today! It is an ingenious solution to regulate the pressure which I will go into below. But first I will describe the cleaning process.

Looking at the Pstat it is quite dirty and there is some rust on some of the grade 8 metal. Here is how I took it apart. Looking at the top you can see the four electrical connections with the two mercury ampules. This is the Sirai equivalent of the switch breaker with the mercury. They are connected to two ceramic bricks that allows you to connect the pstat to the rest of the circuit. It can hold two phases, one for each ampule.



Taking off the ceramic blocks is first, followed by the ampules by unscrewing three screws in total (two for the blocks and one for the ampule).



Next you unscrew three screws connecting the upper assembly to the bellows base. You can then unscrew the pstat adjustment gear afterwards. You can see how dirty the bellows is.



With the assembly off you can simply take out the pin and remove the metal block. Looking from the top you can see in the middle left the number 79 inscribed on the plate, the year this machine was made. It indicates the pstat is original with the machine and I personally like the little touch they placed onto the pstat. There are two 7mm bolts you unscrew to get to the final part: the flexed metal.



Here are all the pieces laid out, in order of disassembly from right to left.


You can see some bluish coppery stuff comes out of the inlet from the base.


I cleaned all of the parts in vinegar except for the main assembly plate and the piece holding the stainless steel flexed metal piece. I used 600 grit sandpaper for everything. I ensured anything copper/brass was not in the same tub with steel pieces as I found out unfortunately the steel will corrode in the solution (my casualties were washers, so they can be replaced. I think an earlier Faema Urania resto thread mentioned this as well).

I also cleaned and polished the cap. I used soapy water to get rid of coffee residue (the ceramic blocks were also cleaned this way) and then used some more jeweler's rouge and the string buff for the polishing. It turned out pretty good but I know I can always improve.





Here is the reassembled pstat. It looks pretty good now after buffing the base a bit.



Here's how it works

On the bottom is the inlet for the connection between the pstat and the boiler. In the brass base there is a copper bellows that rises with the pressure. A circular gear with a pin screws onto the bellows and rests against a metal block with a pin that goes through one end. It in turn pushes against another pin that rests against a flexed piece of metal on top that controls the angle of the ampules. When the machine is below the set pressure cut off the ampules will be in rest position. This means there is an electrical connection, where the mercury acts as a conduit between the two poles.


As the pressure increases, the bellows will rise and push the flexed metal. Eventually a threshold is reached and the ampules will be pushed like a seesaw by the bent metal piece. The mercury will form a blob on one end of the ampules and cut the electrical connection. As the pressure decreases the ampules will slowly bend back and eventually turn on again. It is quite cool how this mechanism was designed and how much attention was given to it. For example to ensure the ampules do not bend so far they can not be bent back, there is a hook piece seen on the right that holds the ampules while bent. There is also a small copper piece that holds the adjustable pstat gear in place when you reached a desired pressure.


Here it is covered with the cap.


One question I have is if this will be safe to use with 20A on 110V, as it can be seen the ceramic blocks say no more than 10A. Would that simply mean I change out the wiring?

I also took a look at the manometer. It was dirty but it works. Any idea on how to clean the face? I tried soapy water already to no avail. Perhaps it will stay to show the age of the machine.

Nice progress on the big clean-up.

I bought a tube of this grease( https://www.amazon.com/gp/product/B079L ... UTF8&psc=1 ) to see if it be okay for lubing the top works. Looks good initially and does not stink, I still have to check the temperate stability at 200-210F.

That is exciting to know. If that stuff works I can order direct from Amazon and have it on my doorstep in days! Tell me how that goes.

Today I primarily did the gas assembly. It was pretty straightforward but I saw some parts I know absolutely I would not be able to source if I lost/broke them...

Taking Apart the Gas Assembly and How it Works
The gas assembly is probably not used as often now in bars but they have their uses in portable setups (ie in vans). This machine definitely was gas powered from the soot markings on the boiler. I will probably not use it but that does not give me the excuse to leave it dirty.


Taking off the copper pipes using a 17mm wrench is easy enough. Getting the the regulator there are hex grips to allow the part to be held by a vice and loosened with a 22mm wrench.



Taking the nipple apart also required a vice but nothing was stuck for long.


The inlet valve was the last thing to come apart and I took all the parts and cleaned them first in Joe-Glo then descaled some of the brass parts where the boiler water touched the regulator.


Here is the cleaned up assembly after polishing stuff up.


Here is how the gas assembly works:
The inlet is where you hook up the gas line and where you control the flow level of the gas. When first turning on the gas you take a lighter to the burner below the boiler to ignite the gas.


Once the machine is warmed up from the gas, the pressure must be regulated. The regulator is a nifty device where it controls the burn level when a certain pressure is reached. This is done by the copper pipe connected from the top of the boiler (the long vertical one). The pressure from the boiler will press against a rubber bellows that is connected to a spring and piston. When a certain pressure is reached the spring will compress the piston such that the gas flow will reduce and cause the pressure to drop from the low burn level. This pressure point can be adjusted with the screw nut on the left part of the regulator. One thing I did not figure out was the flathead screw in the regulator. I think it is a cutoff valve but I do not know for certain.


Finally the nipple is placed into the T-shaped burner that rests under the boiler. The nipple has a cap so no gas will escape outside while burning.


I started cleaning the exterior panels, which are Inox steel, and I am having a difficult time getting the aged coffee grime off. I started with soapy water but I want to get the nice shiny look. First, what is a good method of getting that grime off without seriously scratching the metal? I have some Noxon cleaner/polisher; would that work once I get the grime off?




Finally, I have run into the issue of an ordered part estimating a long time to reach me. The 110V 2kW heating element will take an estimated 12-16 weeks for it to arrive on my doorstep

The good news is I will not be rushing to complete the machine at olympic speeds so I will likely be more attentive to my work as I put everything else together again. Guess it will be close to a year after I first bought the machine before it will be functioning again in February!

Regarding the mercury pstat: did you take a good look at the bottom part, the pressure chamber? Could this be opened? The upper surface of the diaphragm showes signs of corrosion, a hint of a leaking gasket.
The base might be screwed in itself.
On my earlier Oriones pstat the bottom of the pressure chamber is attached to the top with 6 screws, the diaphragm is held inbetween with an o-ring as gasket...