Rancilio System CD 2Gr Restoration/PID Conversion/380v to 220v Wiring

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by Stine »

So I recently moved back to Italy for a little, and found an old commercial machine set to run on 380v (which is the standard for commercial applications).
The machine is a Rancilio System CD 2 Gr, HX I believe, with a 3000W heating element connected in wye.
Having lots of time I decided to completely overhaul the machine and make a few mods to use it at home, on a standard 220v line.
The machine comes with a rotary pump 220v motor, and the heating element itself is a 230v one, so it should run no problem on 220 (given the proper wiring, which I am currently trying to figure out).

I just ordered wires, connectors, pid controller, k and rtd sensors to choose one of the 2, SSR and a few caps and bolts to close the openings I won't use.

The machine also had a gas heater below the boiler (not sure why to be honest, if someone can explain why I'd appreciate it), I removed it.
The original breaker, gicar box, main switch have been taken off the machine as well.

I still have a few questions regarding some of the components, if anyone knows please shoot away, any help is welcome:
What is this white 6-pole connector?

And is this screw on the side of the rotary pump for water pressure regulation?

More to come...

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#2: Post by ira »

380 is 380Y or effectively three 220V legs and a neutral. You need to connect the neutral to one side of the 220 and all three hot legs together and to the other side of the 220. You will triple the current draw on the one incoming leg so make sure the breakers and wire feeding the machine is correctly sized. You can also unhook one or two legs of the heating element to lower the amperage requirement. Looks to me like that white insulator makes it easy to just connect the 3 phases and it distributes the power to the elements. In your case you might have to remove it and power the elements individually.

If the pump has a capacitor, then it's likely a single phase motor and will just run on 220 like normal.



#3: Post by Stine »

Thank you for the reply!
I checked the product number and it looks like it's a thermostat ??? Very odd... (The white 6 pole thing behind the heater)

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#4: Post by civ »

Stine wrote: ... looks like it's a thermostat
That's because it is a thermostat, of the manual reset variety. 8^)
Fits into a well that runs over the length of the heating elements.
It is an industrial class machine running on 380V so it has has six poles wired as a 3PST switch instead of a 2PST switch on a 220V one.
All three phases will trip at ther same time in case of a temperature excess.

See the parts diagramme:

Image courtesy of espressoparts.com




#5: Post by Stine »

Thank you so much for the clarification and the diagram!

So now the question is, should I keep it on the machine despite the re-wiring to act as a safety mechanism?


#6: Post by JRising » replying to Stine »

Yes, Absolutely.
If/when one of the elements develops a pinhole and water leaks inside, the entire grounded boiler becomes the neutral (Actually earth) connection for all three phases and it would heat until the hydraulic safety blew without the electrical safety thermostat.

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Team HB

#7: Post by Jake_G »

Stine wrote:Thank you so much for the clarification and the diagram!

So now the question is, should I keep it on the machine despite the re-wiring to act as a safety mechanism?
I would keep it, too.

I'd also keep the factory 3pst (or is it 4p?) switch. It distributes the current through 3 different sets of contacts and will basically last forever. It is also setup to deliver power to the autofill circuit, but not the heater in position "0". This is great for cold starts and any time the boiler is emptied.

Setting "1" sends power to the heating element, as well.

I'm not sure if you're planning on operating the machine without the autofill circuit but if you retain it, I'd retain the switch, as well.


- Jake

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#8: Post by civ »

JRising wrote: Yes, Absolutely.
Indeed ...
JRising wrote: If/when one of the elements develops a pinhole ...
This is actually a manual reset thermostat/klixon type protection to prevent the element going south in case of a low water level situation.
ie: element overheats, temperature rises above the factory set level and the klixon trips disconnecting the three phases at the same time.

Electrical problems such as the one you describe are actually taken care of outside the machine, which should be properly grounded and on an independent circuit, via a GFCI device.




#9: Post by Stine »

To be honest I am still thinking wether to keep the auto fill function for the boiler. I only brew espresso, sometimes using hot water for americanos, but don't really use steam and/or make lattes or cappuccino.

I was also thinking to change the main switch, but since the original one seems convenient I might keep it. I'll post a picture of it so you guys can help me identify the separate phases and how to wire it properly.

This is my first time working on a heath exchanger (the previous rebuild I did was on a single boiler e61, so I was planning on starting from the circuit I draw for that one and modifying it accordingly).

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Team HB

#10: Post by Jake_G »

Even if you never steam any milk, you still have to have water in the boiler to transfer heat to the HX and to keep the heating element from overheating and self-destructing. There will be water loss over time and that needs to be replaced. The system CD also uses an "economizer" for hot water dispensing (which is nothing more than a mixing valve). This draws superheated boiler water and blends in some fresh water to give a useful temperature of hot water out the tap. (my mistake. Only the Tecna has this feature. The system has a single solenoid that draws water from the boiler.) This is very convenient for rinsing the portafilter after use, warming a cup before a shot, etc... the auto-fill controller also uses input from the hot water switch to cycle the pump and solenoids for this function as well as for replenishing water in the boiler.

Turning water over in the boiler is a good idea, regardless of your need for steam, as minerals build up over time as water is lost through evaporation and heating cycles. Flushing some water out aids in keeping the drip tray clear and the hose from the drain box flowing freely. Coffee solids are expelled into the drip tray after every shot and without a little help, those solids can clog up the drain tube and lead to messy situations. Using water from the boiler for other things and letting that water wash down the drain is a good practice.


- Jake

I see the System also has a manual fill valve and a sight glass. Using these to keep the boiler topped off is a fine approach, but if the autofill circuit is functional, why not keep it for convenience? My MIDI CD had neither a manual fill valve, nor a sight glass, hence my comments above.