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Upgraditis: 2-group Grimac Commercial

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  • Re: Upgraditis: 2-group Grimac Commercial

    JavaB, the needle still oscilates, but only within probably 0.1 of a bar.

    That 9 bar I mentioned was without a loaded basket.... There seems to be a marked variation in pressure between no load and loaded -- up to 4 bars.

    When I went to brew, it was more like 12 bars, so I backed off.... then too much. I actually brewed a fairly acceptable shot at 5 bars! Still tweaking, and as Im running out of beans (as always) I have to be sparing.

    I dismantled the three-way valve last night. It had started leaking during extractions and I suspected it may have had some dirt, but all I found was an exceptionally clean valve body! No coffee oils, no grit. May have been a weak spring, or the coil was holding the plunger open a little.

    Ill know tomorrow.

    That preinfusion system is interesting.... the pressure goes to about 12 bars, then the solenoid valve opens, pressure falls away and water is spent into the drip tray.

    The pump starts up again, at about 5 bars, and slowy ramps up to the desired pressure.

    Seems to work.

    --Robusto

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    • Re: Upgraditis: 2-group Grimac Commercial

      Robusto,

      Methinks your pump is designed for positive pressure on the supply side. Thats the only way the pressure delivered would vary so much. Its not really designed to raise the pressure by 9 Bar but only 5 Bar or so. The only other possibility is that it has already died - and I doubt that.

      If the requirement for a pressurised supply is in fact the case, running it without the required 3.5+ Bar will cause premature failure. (La Cimbali say NEVER to run the pump in their machines that way for example).....

      Looks like plumbing required.

      Comment


      • Re: Upgraditis: 2-group Grimac Commercial

        JavaB, its a Procon, and I mentioned about needing to be plumbed in to the Grimac technician today. He said no need, for positive pressure or pre-infusion.

        But the pump does make quite an audible hum --- I dont know what they are supposed to sound (or not sound) like. Whether you really have to strain to listen for it running. Theres no straining required here, the pump lets you know its on.

        Is the case with your pump that if you run a blind filter, you get 9 bar, that if you remove it you still get 9 bar, and when loaded with coffee its still 9 bar? What does it sound like?

        I suppose I could rig up an experimental garden hose "plumb in" and note the results.

        -Robusto

        Comment


        • Re: Upgraditis: 2-group Grimac Commercial

          Robusto,

          A procon is fine drawing from a reservoir...... so that cant be the problem (unless it has been replaced at some stage by a different brand - check the label on the pump to make sure).

          You can hear my pump running (well I think it is actually the motor I can hear but it is pretty quiet). I get a little (what I assume is ) pump noise when I have both groups running (no PF) and the hot water on as well.... sounds a bit like shhhhhhhhhh (guess its lots of water moving)....

          I rechecked and I get a maximum variation of about 0.2 Bar (bit hard as its not calibrated to that level - so guesstimated!!) from no load (blind filter) to everything running.

          So maybe your pump is a little tired

          Comment


          • Re: Upgraditis: 2-group Grimac Commercial

            Thanks for the info. The pump probably is tired -- but not to the degree where performance is an issue.
            (yet)


            --Robusto

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            • Re: Upgraditis: 2-group Grimac Commercial


              wrto procon pumps; they are definitely specced to run from a tank and even draw water up from 2m. Ive been reading a few threads on HB lately on this issue and it seems that even Schomer the Great prefers to draw water from a tank to ensure a stable pressure (ie. he doesnt trust line pressure fluctuations and the ability for regulators to steady the pressure to his satisfaction. His setup is a reservoir that is continuously topped up to retain a nearly constant water level. A bit over the top, me thinks. Anyway, quite a few people talked about running off tanks with procon pumps for many years without problems.

              My pump isnt quiet, but again thats probably more the motor and how its mounted. SOme commercial machines are whisper quiet. However, some machines have an outboard pump mounted somewhere under the counter.

              Cheers,

              Mark.

              Comment


              • Re: Upgraditis: 2-group Grimac Commercial

                Yes, I read that about Schomers tank -- in case there was a minute variation in the line pressure during the extraction. I think the same post derided him for supposedly being able to taste 0.1º temperatures.

                Although the pump can run happily from my 10-litre tank, it doesnt self-prime, or, doesnt appear to.

                I have to bleed out water/air, usually from the pipe going into the pressure gauge, before it primes. Perhaps there is a better, easier way that doesnt create mess.

                My wifes on her way home with a new solenoid coil and two-hole steam wand.

                Should be an interesting night here.

                --Robusto

                Comment


                • Re: Upgraditis: 2-group Grimac Commercial


                  Ahhh, so both Mr and Mrs Robusto partake in the tinkering. Thats real love....

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                  • Re: Upgraditis: 2-group Grimac Commercial

                    Coffee, the ties that bind. :-* :-* She loves her latte. I love to tinker to make it happen. Perfect love match.

                    --Robusto

                    Comment


                    • Re: Upgraditis: 2-group Grimac Commercial

                      Hows the steaming on the new machine? Ive just got my 2 grp commercial futurmat machine running yesterday, and I am overwelmed by the pressure, compared with my old silvia.. a much similar situation to you... Im testing it on the hose water connection, it seems to work ok for me... you must have a very understanding wife to allow that beast in your kitchen! At first I thought I was mad getting a 2grp machine, but nice to know im not the onlyone whos mad!

                      Its probably already been asked, but what power do you run it on?

                      Comment


                      • Re: Upgraditis: 2-group Grimac Commercial

                        MachoSilvia, there are a few mad 2-gropup commercial machine owners here. Sparky and JavaB are at the top of the heap with their techno-wizardry.

                        Congratulations on adding to the team with the Futurmat. How about some pictures and details please?

                        Steaming is a big learning curve after mastering Silvia. Its easier if you use a large jug. In any case, its a matter of mastering many variables: position of the wand, depth of the wand, steam volume, angle, hand steadiness, and being aware of the idiosynchratic noises which sussgest success or faiulure.

                        Even before I received mine, I measured out the space it would take where Silvia formerly was, and knew it was going to be a huge enchroachment. But its yet to go there -- its still on the breakfast bar side of the kitchen.

                        When we built out house we had 15Amp supplies and 410V 3-phase installed, so power is not a problem.

                        Good luck and keep us all posted about your Futurmat journey


                        -Robusto

                        Comment


                        • Re: Upgraditis: 2-group Grimac Commercial

                          Ive mentioned before that the pressure gauge oscillates and that the pump pressure is halved when two groups are used simultaneously....

                          This morning I hooked up the water intake to a tap.

                          I was able to run both groups at once at 8 bars.  -- JavaB and  Sparky, youre right, the pump does rely on a boost from incoming water pressure.

                          Secondly: The gauge pointer oscillation has disappeared!!! Its rock steady now -- even after removing the mains hose and going back to the tank. And dare I say it, the pump also seems quieter.

                          Some sort or air lock earlier perhaps?

                          The new Rancilio pressure gauge is installed on the outside panel where it should be and works well

                          The replacement solenoid has also (so far!) cured the leaking to earth problem.

                          The new two-hole steam tip is rather slow, the holes are miniscule. Have only done one latte with them, but it allowed me to maintain control throughout.

                          --Robusto

                          Comment


                          • Re: Upgraditis: 2-group Grimac Commercial

                            Robusto,

                            Good to hear its all working properly now, and that gauge looks really good (and saved some pennies as well!)

                            Id be looking at the label on the back of the pump.... It doesnt sound like its a procon - you shouldnt be getting these issues if it is - as Mark said they will actually draw water from a tank lower than the coffee machine.

                            Maybe in a past service the pump has been replaced and they used some other brand (to reduce cost - or because thats all they had at hand.....). The procon label is clearly visible on the back of the pump......

                            Comment


                            • Re: Upgraditis: 2-group Grimac Commercial

                              Thanks JavaB. Any theories on the end to gauge oscillations after having temporarily attached to the water main?

                              (Ive been trying to attach multiple pictures, but Im afraid Im doing something wrong --- is there a step by step guide!!!)

                              --Robusto

                              Comment


                              • Re: Upgraditis: 2-group Grimac Commercial

                                You need to host them somewhere first.
                                Like on Photobucket or similar.

                                Then you paste the individual photo links into your post (suitably image tagged).
                                The alternative is to splice them all into one photo and post normally.

                                e.g.

                                Comment

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