VBM Junior HX wiring diagram anyone? - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
Just Mike (original poster)

#11: Post by Just Mike (original poster) »

Thanks Frank, I hadnt spotted that. I have at least found a serviceable socket to replace the one I have as only available otherwise as part of a harness usually for $120 vs the $6 as a single item from an electrical store.. If the RELPOL is rated at 10A despite the predictable current flow being 30% higher that would make the machine defective by design, which is a bit disappointing.

I plan on moving back to Australia in the next 2 years so might look at the electrics in detail now if the plan is to reverse engineer it back to 240V then.


#12: Post by fsatira »

Hi all,
Just to follow up, I found my crude sketch of original wiring, as well as EricS partial clean up diagram. Notice on both line and neutral are reversed- I did change to proper connection on my machine. If I recall, I ran a wire from line to one load terminal of the SSD, then the other load terminal to the element. The second element lead went directly to neutral. For the SSD switch side, I connected the lead from the P Stat to one terminal, with the other connected to a SPST switch, then to neutral. I use the switch to turn off the element, and did not want it switched to high current. The risk taken is if the SSR fails closed, then the switch will not work. Has not happened in 9 years. As long as you uprate the SSR and place it somewhere where it can radiate the heat it should be OK. I placed mine with some thermal paste on the floor under the water reservoir.

I removed the relpol cube relay, I think joining terminal 5 to 8 and 1 to 4 on my crude diagram, and getting rid of the leads from the coil to the solenoid.. The thermal overload switch is now low current as well, on the same branch as the P-Stat.

I hope this helps, if you want to do the same conversion. Double check your wiring in case it differs from the diagrams.


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Team HB

#13: Post by homeburrero »

Nice work on that 2009 Vibiemme Domobar Junior HX electrical diagram Frank!

(I'm repeating your image here right side up for convenience.)

It's interesting to me how they used that 8 pin DPDT relay. I was surprised to see that it does nothing to reduce the load on the pStat, and it's only a 10 amp relay switching the full load of the element, which is around 13 amps on a 120V element. Not only that, it runs the full element current through both contacts in series on the side of the load that has the safety thermo. Its only real function appears to be to open the heater circuit whenever the autofill solenoid is powered. Oddly engineered to me but I suppose the VBM designers maybe know something that I don't.
nínádiishʼnahgo gohwééh náshdlį́į́h

Just Mike (original poster)

#14: Post by Just Mike (original poster) »

Many many thanks Frank. Nice work.
After much effort I removed the heating element and it seems ok - clean, some scale, but nothing remarkable. However resistance is 7.4 ohms. That means current flow close to 15 Amps. even if I rewire my burnt out relay socket Im looking at lots of heat from that flow.
- should I replace the heating element and hope I get a version closer to 9 ohms and at least drop my flow down to 12 Amps? What if I just get another 7 ohm heater element - waste of $$
-Should I look to a 1200 W or heater element with similar dimensions and thread size?
- Should I just rewire and hope for the best?
- Should I rewire the whole thing as 240 v with new 240 v heater element and use an external transformer to run the machine at lower amps overall? (I have that anyway for my grinder from when I came from Europe)

Thoughts appreciated ++

Just Mike (original poster)

#15: Post by Just Mike (original poster) »

OK some brief research shows an option
- For Wega Lyra/Mini Nova/Mini Wega and Astoria CK/CKXE. Old part number W17201. 41 mm. Immersed Length 100 mm from inside flange. (1 1/4") outside diameter threads. SKU: W80001
This seems to have the right depth right flange size and be a more reasonable wattage. even the shape is similar. Yes it will take longer and cycle more no doubt, but I am producing 2 coffees each morning (4 on weekend mornings).

Heating element gurus - any thoughts? I will notice the drop 1600 W to 1200 W but will that be offset by having more sensible current flow?

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Team HB

#16: Post by Jeff »

The resistance of heating elements changes a bit with temperature, so that element may be "just fine". 1600 W is well below the 1800 W "limit" on household circuits (15 A at 120 V). My Anita sticker shows 1500 W at 115 V, so that seems in line with 1600 W at 120 V.

Running an espresso machine that draws over a kilowatt on a step-up transformer is asking for trouble. The inefficiencies of the transformer may mean that you're drawing 1.5 or 2x the load power from the wall. Then there's that most affordably-priced, consumer-focused step-up transformers are laughably over-speced and wildly unsafe from just a basic electrical perspective. I worry about running a 600 W, 230 V machine off one that claims 1500 W or something silly like that.

Edit: I've been following a Quick Mill thread as well. I don't know if Chris' Coffee can help with VBM parts or not.
You might reach out to Chris' Coffee service to see if they have the heating element available, if yours turns out to not be serviceable. They have been the premier Quick Mill dealer in the US for many years. Their service and parts department have always treated me well, saving my probably hundreds of dollars over the years.

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#17: Post by cafeIKE »