Hi
I recently picked up a Cimbali M30 Bistro. It was just too good a deal to pass up. The problem is I can't plug it in! It is a 110v 20 amp machine and I have only 15 amp circuits in my kitchen. Rewiring is not an option because I'm renting.

So... after doing a bit of online research it occurred to me - the Cimbali Junior DT/1 is a 110v 15 amp machine. The two machines *appear* to have the same boiler (2.25l) and the same element mount. Does anyone know if they are in fact identical? Can I simply pull my element out and stick in one meant for a Junior DT/1 thus making this a perfectly functioning 110v 15 amp machine?

Here are a few pics of my new beast. Hope they help:

It seems very clean, inside and out - no signs of leaks or burns anywhere!







Here's the boiler. I've read threads about other Bistros, their boilers seem to share the model number 495007 but the last two digits are not always the same. I've seen 91 and 92 - mine is 93... leading me to believe that's the date of manufacture.



Now with heating element cover off. I forgot to get a good pic of the model number, but it is 321032, 115v/20amp [EDIT - it's also stamped 1800w. By my math that's 3 coils @ 600w each], and is stamped 10/92. You'll notice in this photo something that I thought very curious - there are 6 spade connectors sticking out of the element but there are only 4 wires connecting to them. As you'll see in in the photos below, this element has 3 heating coils. If 3 coils are 600w each, does this mean that someone has wired this machine to run 2 coils at 1200 watts (and a low enough amperage draw to run on a 15 amp line!?!?)



Element removed. Some scale... not too much. Soaking in Dezcal as I write this. You can clearly see that there are 3 individual coils. And... one tube (in front). What does the tube do? Half of the element gasket is attached to the element...



The other half is still stuck to the boiler. An even closer inspection revealed that there were two gaskets, one stacked on top of the other. I measured the opening where the element sits - the Inner diameter is 50mm and the outer diameter is 58mm:



Another shot of the ruined gasket. I'm already starting to make a shopping list of goodies needed to bring this machine back to her former glory:



While still scratching my head about how to solve me heating element problem I decided to get to work on the more mundane cleaning and maintenance tasks. Nearly everything in the machine looked very clean except this! All I can say is NEVER let you grouphead look like this - YUCK!:



And GROSS! I've since completely disassembled this end of the machine and these bits are spotless... but, man, I can't imagine what the espresso was like out of this thing! Who let's their gear get like that?:




So... If any of you have tried this element swap or have any other suggestions about the best way to make this machine run on 15 amp circuitry I would be glad to hear what you have to say. Any thoughts on the photo of the element showing the 6 spade connectors but only 4 wires? Does it seem to you that it is ALREADY wired to run on 15 amps using only 1200 watts of the 1800 available? Maybe the solution is staring me in the face.

Thanks in advance!
Alex.

Hi,

I am no longer using my Cimbali Junior DT1, which currently resides in the basement. I did however take a lot of pictures of the internals when I first bought it, more than 5 years ago. Looking through my photo collection I came up with this side view, which shows the same side view of the boiler as you posted of your machine:



Looking at this side view it appears that the boilers in our two machines are quite similar, down to the model (if not version) numbers. The element mount appears to be the same, although the element wiring is obviously different. If I had to guess whether you could put a Junior element (of that vintage) into your machine I would guess "yes," however exactly how you would wire it I don't know. In addition, your machine has a lot more electronics than does the Junior (which used to have almost none in older versions but in the DT1 version I have, has some) and there is no telling how the brainboard will react to having a different, lower wattage, element installed in it.

One thing I could suggest is that you might call a dealer to get some confirmation that you can do this. I have had very good dealings over the years with James and Wayne at Bravo Coffee in Vancouver, the BC importer and dealer in Cimbali machines. They are knowledgeable about the product line and they could probably tell you directly whether you can do this modification and get away with it. They could also sell you a Junior element, if they thought it would work. They both do a lot of hands on repair work and refurbishment, so they would know of what they speak.

Good luck.

ken

I don't think the electronics will be overly upset by a different wattage element. The main difference you might notice is that it takes longer to get up to pressure and longer to recover from cold water inflow, but in a domestic situation this probably isn't a concern.

As to the 2 versus 3 elements being used, the current draw will be the sum of the draw for however many you have in parallel. If yyou are right that the machine is 2400 watts with 3 elements, then you are probably okay with only 2 in line (1800watts, 110volts, roughly 16.36amps) Do you have access to a clamp meter? You can then test the current draw and know the answer.

The extra hole in the element looks like a thermowell to take a thermostat for overload protection. In Ken's picture you can see the wire going into the hole.

Unfortunately I have nothing to add, other than to note what excellent photos you've taken!

EDIT: Alternatively, if you are worried about plugging it in as is to determine the current draw directly, if you have a multi-meter you should be able to measure the resistance of the elements and therefore derive the amps/watts without plugging it in.

This site is definitely one of the most helpful espresso boards out there!
Thanks Ken, your photo is very encouraging. As you mentioned, very similar to mine. When I went looking online for replacement Junior elements they all seem to be 1300w. Yours is stamped 1200w. If my theory is right, mine might be set up at 1200w right now. I wonder if the extra 100w is even worth buying a new element.

Nick, thanks for your input. I've edited my first post for clarity - my element is 1800w and has 3 coils, so I believe with only 2 of three coils connected I'm drawing 1200w... sound right? Also, interesting point about the thermostat - this tube is accessible from the outside on mine as well but there's no wire... guess I'll go fishing around the bottom of my machine to see if it's come loose somehow. Is it possible mine doesn't have it or need it? Perhaps it's located somewhere else.

Chris, yup I'll have to go find my meter. I definitely don't want to plug it in until I have a better idea... especially now that I've cracked the boiler gasket! Oh and thanks about the photos... just though that good shots might get better advise. Seems to be working so far!

just though that good shots might get better advise. Seems to be working so far!

This is so true - there is nothing better than a good photo array and you have certainly provided that.

When you locate your meter and measure the resistance of each heating element, the value should be AROUND 20 ohms each. So if two elements are connected in parallel, the circuit resistance is 10 ohms and if three elements are in parallel, the resistance is 6.67 ohms.

For an AC circuit having a pure resistive load, the wattage developed is proportional to the voltage squared, i.e., P = (E squared)/R . So, the mfg is assuming you have a nominal 110V available whereas you may have more, i.e. 120V. Voltages vary all over North America and, of course, the available voltage drops a little when the rated power is being consumed.

I have finally gotten a chance to test the resistance on my heating element. All seems in order. Eric, I'm getting readings pretty much spot on to the values you expected - about 20.5 to 20.8 for each element, 10.5ish if I bridge two elements. I'm now confident that if I put the machine back together just as it was I'll be drawing 1200 watts, well within the 15 amp load on a regular circuit. I'm already running a different 1400 watt espresso machine and a Macap grinder with no problems. (I won't, of course, turn both espresso machines on at the same time!)

So... element issue seems solved. Use what I have @ 1200w. If I really want, get the replacement Junior @ 1300w, looks like it's 100% compatible.

Still one nagging issue though... that darned empty tube in the element that as NickA mentioned, "looks like a thermowell to take a thermostat for overload protection." I went searching inside my machine for any wayward wires and came up with nothing. Um, well... almost nothing! Take a look at the picture below showing a bundle of wires that include the autofill sensor wire. This seems to be factory tie wrapped. If you look closely you'll notice 3 wires that are bent back on themselves and shrinkwrapped in clear plastic! Any ideas?



And here's a closer look at the same wire bundle. Looks like it came this way straight from Cimbali - very tidy. It's hard to tell from this angle but there are definitely 3 wires that are bent over and retained in this clear plastic sheath. Six wires together at the bottom of the frame, three wires can be seen going off to the left, the remaining three are bent over and end here. Could this be an unused connection for an overload thermostat?




Assuming I get a new gasket and remount the element, am I safe turning this thing on without first solving the thermostat issue? Anyone ever see a service manual floating around for an M30 Bistro? I've seen mention of user's manuals, but nothing that describes the inner workings. As always, I really appreciate any advise you have!

Alex G wrote:I'm now confident that if I put the machine back together just as it was I'll be drawing 1200 watts, well within the 15 amp load on a regular circuit.

And you'll have a built in 'spare' heating element if one should fail!

Hi Alex, the fact that the element has a thermowell doesn't necessarily mean that your model was fitted with one. The element may be used in other models that do have a thermostat. If you have a thermostat fitted, it will probably be a cube about 1.5 inches in size. It is a like a contactor that can break the current to your boiler if it overheats. You can follow the wires from the boiler back to see if they go through such a switch.

You may want to check with the agents as to whether your model came out with a thermostat for peace of mind, but certainly not every coffee machine has one.

I did this on my Elektra T1 with good results so far (2 years).

When we rebuilt the kitchen (a year ago now) I put in a 20 amp circuit, but I've never gotten around to rewiring my system as I'd have to find a digital timer with 20 amp capabilities and they are RARE...

Mark