Results 1 to 25 of 25
Like Tree11Likes
  • 3 Post By noidle22
  • 1 Post By Lyrebird
  • 1 Post By Lyrebird
  • 2 Post By ashwarren
  • 1 Post By Lyrebird
  • 1 Post By ashwarren
  • 1 Post By Dimal
  • 1 Post By robusto

Thread: Gicar 1d5e volumetric controller / board issue

  1. #1
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39

    Gicar 1d5e volumetric controller / board issue

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Hello all,

    I've been working to bring back to life a fairly well worn Boema 2 Group volumetric - probably about 10 years old, what what I can find. After a through descale and deep clean, and replacement 2200 watt element, it's running nicely (and can run on 10amp GPO)

    However, since it got up and running, I've found a new issue. One of the Gicar volumetric controllers (1d5e - 8.5.68.32/A) is switching itself 'off' when the machine gets up to temp.
    When cold, it switches on (lights blink on power) and works normally. But once the machine gets hot, it just won't respond.

    I've replaced the capacitor on the board - as I had an appropriate one on hand, and this hasn't helped - the same thing keeps happening. I'm wondering what the next step should be.

    Does anybody know which components are most likely to fail due to heat? I think the next step is to replace transformer and relays - but I'm having trouble finding the specs for these.

    I'm also not entirely convinced by my 'heat failure' hypothesis, so thought I'd put this one out there - because I can't think of any other explanation. Could it be something else?

    Any advice or help much appreciated!
    ash

  2. #2
    Senior Member noidle22's Avatar
    Join Date
    Mar 2012
    Location
    Bathurst
    Posts
    1,258
    The transformers generally fail in controllers due to the heat and stress, in that particular type of integrated touchpad/controller (fairly sure that's what yours is) it happens fairly regularly.
    The other part that can fail is the main element relay.
    Dimal, ashwarren and Lyrebird like this.

  3. #3
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Cheers! Yes - it's an integrated touch pad/controller, and mounted above the group.

    Looks like some more fun with the soldering iron...

  4. #4
    Senior Member noidle22's Avatar
    Join Date
    Mar 2012
    Location
    Bathurst
    Posts
    1,258
    Parts are cheap fortunately, the transformers can be sourced for under $10 from RS Components. Relays much the same.

  5. #5
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    It's funny you should mention that - I've been trying to find replacement components at RS. Nothing quite seems to match-up with what's on the board, and I don't have the expertise to know what values are flexible...

    The transformer is a HAHN BV EI 304 2082 230V 50-60Hz 12V 2,1VA
    GICAR-TR1.jpg
    and I think the closest I can find is either under the 2.1VA: at 2.0VA ( https://au.rs-online.com/web/p/pcb-t...rmers/7320360/ )
    OR over at 2.8VA ( https://au.rs-online.com/web/p/products/7320389/ )

    RL3 is a JQX-14FW 018-HS - which the data sheet I can find says has an 18V coil, SPST-NO configuration and is sealed.
    GICAR-RL3.jpg
    This one I'm really struggling to find an equivalent.

    The other two, RL1 and RL2 are OMRON G2RL-2A 18VDC, which I'm also having trouble finding.
    GICAR-RL1.jpg

    Any advice about what might be substituted would be much appreciated. I've been doing a lot of reading, but it's a steep learning curve!

  6. #6
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    625
    I'd use the 2.8 VA Tx if it will fit (check clearance to the cover on the Gicar unit), overrating the Tx ensures it will run a bit cooler and hopefully last a bit longer.

    For RL3 you could use RS part 718-1991 18V 16A SPDT relay, just cut off the NC pins and you have an NO relay.

    Assuming this is the element relay, an alternative would be to pick the relay drive voltage off the board and take it to an SSR mounted on the chassis.

    I can't help with a direct replacement for the 18V Omron relay. It is possible to convert to 12V but it's a bit of dicking around.
    Last edited by Lyrebird; 28th August 2019 at 11:26 PM.
    ashwarren likes this.

  7. #7
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Thanks Lyrebird - that's really helpful.
    I'll replace these two parts first, and see what happens!
    Also - hadn't even thought to check clearance - good point! After a quick measure, it's pretty tight, it looks like I'll got for the 2.0VA.

  8. #8
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    625
    If you substitute a lower rated Tx is will run hotter and fail earlier. I would advise against that unless you also do the SSR mod: the SSR takes much less drive current than a mechanical relay so it reduces the total load on the board. It will also last longer.
    Dimal likes this.

  9. #9
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    That's a real catch 22! I'll either have to modify the controller unit box somehow to fit in a bigger transformer, or run out to an SSR...

    However, now I'm wondering exactly what that 16 amp relay is responsible for switching.

    There machine runs just fine with the volumetric pad/controller out of action - the manual switches continue to work, and boiler cycles as normal. So I'm assuming that this controller is switching on the rotary pump and some solenoids.

    There's also another box under the drip tray that seems to be handling the boiler auto-fill. Looks like my next task is to try and make sense of the tangled bunches of wire.

    Thanks again, by the way. I really do appreciate the advice. I've been away from this forum for a while, and had forgotten how great this community is.
    Dimal and Javaphile like this.

  10. #10
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    625
    OK that's interesting, I'd assumed it's the heating element but it might be the pump motor: motors are a bastard of a load to switch (very inductive) so it's usual to over rate a relay significantly.

    BTW the above applies to SSRs as well: good info from Crydom re SSRs and motors here.
    Dimal likes this.

  11. #11
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Cheers! I've got my hands on a BOEMA parts list, which shows (sort of) their configuration. I'll put the pic below as it might be helpful to others (and I'll try to upload the whole pdf on the documentation page).
    Boema-Wiring-Spareparts.jpg

    It looks like there is an RL40 main control board, and a volumetric unit (in my case, two). I think you're right - that relay is probably switching the pump.

  12. #12
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Parts arrived - and problem solved!

    Took the time to put in the new components one at a time - to try and isolate the issue, and nailed it first try: the transformer (just as noidle22 suggested).

    Machine working a treat now, and I've been pulling coffee all weekend. Despite not being designed with much consideration of ergonomics, I'm impressed with the shots coming out the machine. It's pretty forgiving.

    After noting a fairly high pump pressure when just purging the groups, I'd be interested to know what from other Boema owners what kind of pump pressure they read when running water through the groups (ie - with no coffee).
    Dimal likes this.

  13. #13
    Senior Member robusto's Avatar
    Join Date
    Feb 2005
    Posts
    3,098
    I would say pressure through the groups without portafilters should be the same 9 bar as with a blind basket or loaded portafilter.

  14. #14
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    17,584
    With little resistance to water flow, the observed pressure should be significantly less that normal brew water pressure. Hard to say what this will be exactly given that there may be gicleurs fitted into this hydraulic circuit...

    Mal.

  15. #15
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Hi Robusto and Mal, yes, I'm getting roughly the same 9 bar reading with and without loaded portafilter. A tiny smidge higher with a blind basket.
    I had thought that the resistance would be much lower, like you suggest Mal, and was trying to think if there could be a blockage somewhere, but was getting the same reading on both groups, and a much lower pressure when filling the tank (around 3 bar). Then I found the pretty small restrictor/gicleur that's a part of each group, and figured they could be providing the resistance. I am surprised that it is so high.
    It's also worth noting the brew pressure gauge is looking a bit tired (was stuck initially, and showing nothing) so I don't have the greatest faith in its accuracy. Next on the list of parts to replace, I think.

  16. #16
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    17,584
    Ah, Ok...

    Sounds like the Brew Water Pressure gauge is fed from a tee that is upstream of any water pressure bypass protection. Not very handy when one is trying to troubleshoot. I wouldn't expect the group gicleurs to cause such a significant back pressure though, maybe one of our CS Pros could add some guidance here...

    Mal.

  17. #17
    Senior Member robusto's Avatar
    Join Date
    Feb 2005
    Posts
    3,098
    The role of the gicleur should be to tune the thermosyphon temeperature....too big an opening and the group head overheats.

    On my machine the gauge is most properly working properly, and pressure with blind filter, with loaded portafilter, or without portafilter remains at the setpoint of 9 bars.

    The gauge may be fixable if it can be dismantled easily. You can then see if the system of levers and cogs is sticking.

  18. #18
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    625
    You need an orifice diameter of about 0.4mm to get 900 kPa backpressure at the typical flow rates from an Ulka pump ( ~250 ml / min @ 900 kPa) Group jets are typically much bigger than this.

  19. #19
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    17,584
    Yep, thermosyphon control and brew water flow control are two different entities and often use gicleurs of different sizes, in different sections of the hydraulic circuit to affect this...

    Mal.
    robusto likes this.

  20. #20
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Good to know the pressure isn't a one-off! I had opened up the gauge to get it unstuck - but not sure if the unsticking, which changed the 'zero point' of teeth/cogs, altered calibration.

  21. #21
    Member
    Join Date
    Jul 2013
    Location
    Coburg
    Posts
    39
    Mal - yes, the pressure gauge is reading from right after the pump - and before an OPV which was set to kick in around 11 bar - then goes to a 3way intersection for the two groups and boiler.

    Thanks for this info about jets and pressure Lyrebird - the jet is pretty small - I'll see if I can measure it. My memory is that it's not larger than 1mm. Do you know what the flow rate for a rotary pump would be?

    This is all quite interesting! Many thanks for all your expertise!

  22. #22
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    17,584
    Quote Originally Posted by ashwarren View Post
    Do you know what the flow rate for a rotary pump would be?
    Probably several hundred Litres/Hr with an Open Head.
    At ~9.0Bar, would just need to check the Pump Curve but it would still be quite impressive...

    Mal.
    Last edited by Dimal; 4th September 2019 at 05:46 PM.

  23. #23
    Senior Member robusto's Avatar
    Join Date
    Feb 2005
    Posts
    3,098
    Quote Originally Posted by ashwarren View Post
    . Do you know what the flow rate for a rotary pump would be?
    If it is a Procon rotary pump, their web site has lots of information you will find useful including flow rates

    https://www.proconpumps.com.au/produ...0aAqSzEALw_wcB
    Dimal likes this.

  24. #24
    Senior Member Lyrebird's Avatar
    Join Date
    Jun 2018
    Posts
    625
    Quote Originally Posted by Dimal View Post
    Probably several hundred Litres/Min with an Open Head.
    At ~9.0Bar, would just need to check the Pump Curve but it would still be quite impressive...

    Mal.
    These are positive displacement pumps so the curve is pretty flat. The one I am using is nominally 3 l/min (rated at 1 MPa), it only increases to about 3.3 l/min with no head and decreases to 2.8 l/min at maximal allowable head (1.7 MPa)

  25. #25
    Mal Dimal's Avatar
    Join Date
    Oct 2004
    Location
    Warwick, QLD
    Posts
    17,584
    Yep, realise that Lb...

    Due to the pump's output control causing excess water to recirculate through the pump, the actual flow seen at the group will depend on several things.

    Mal.



Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •