Gicar controller blown again - wiring help?

[Ozark_61]

I had an incident last year where my ecm giotto was acting like it was out of water - pump would not work and the heater would turn off. It would go off for maybe 5-10 minutes and on for 1-3 minutes and repeat. Replacing the gimme / gicar relay / controller black box fixed this problem. It's gone out again on me. This time, I pulled it out and took a look. One corner on the external box looks singed and one of the SMC looks like a leaky capacitor (front of picture, to the right of the transistor (I think it is)) I don't have a schematic, but does that seem right according to the pictures? Also - any ideas why this might be happening? Last year it seemed like it may have happened during a lightening storm, but it's been dry and sunny for a while here. I've got to go dig out that moka pot...

Geoff

[MyPoison]

I can't tell if that 3-pin part is a transistor or a dual diode, but anything that size with "103" written on it is a 10K (10 x 10^3) resistor. Resistors don't die unless abused, which indicates a problem elsewhere, and they are utterly incapable of leaking anything. You could test with an ohmmeter, but only a reading >10K indicates a problem. The resistor is 10K, but I don't know what the rest of the circuit it's wired to is, and unless you unsolder it, you're measuring both in parallel.

Capacitors that size are ceramic, and are unlabeled tan/beige bricks, somewhat thicker than the resistors. They also don't (can't) "leak".

Note that thick-film surface mount resistors are manufactured at temperatures of around 1000 F, so you'll unsolder them before you damage them from slow overheating. A sudden surge, of course, is a different matter.

[Ozark_61]

Thanks for the info - I guess no coffee before trying to desolder those.. I don't know if you can see the crud or not that's just to the left of the resistor in question. It's on the pins for the ribbon that goes to the board with the relays (?) on it. I scrubbed it off and it was a powdery white substance. I'm not sure if it was due to arcing (no apparant burn marks), but wondered if it might cause a short in the traces. The damage on the 103 sure looked like a leaking cap, but since it's not, maybe it was a board defect or heat damage? I was wondering about a cold solder joint, but with all those smc, it would take me forever to fix it. As for the relays, is there a way to test them to see if they are still functioning?

[LeoZ]

how are things looking? did you repair or replace?

[Ozark_61]

Well... I'm trying to replace. I replaced dead unit last year, and that's dead (judging from the same behavior I'm dealing with again). The replacement I got last year is labeled 'giemme' and the new one is a 'gicar'. One of the relays in the giemme is dated 12/99 and the gicar board has a date inside of 06/05 - and now the posts for the wiring look different. Can anyone help out? I figured the #8 on the black label was ground (green wire / unshielded terminal). The thin blue wire went from #10 black (giemme) to F9 on the white (gicar)label, which was 'serb' on both. I then assumed the thin clear conductor 's.liv.' (giemme) was = 'cald' (gicar). The rest I'm hosed on. Can anyone help me out? What I have is:

Gicar
F1 - F
F2 - C.Carichi and N
F3 - Res RL1
F4 - Ev Cald RL2
F5 - Pompa RL2
F6 - Abil Erog
F7 - (ground, I think)
F8 - Cald
F9 - Serb

Giemme
Well... just check out the picture. If you guys have any ideas of what wire should go where, let me know! I did find one reference to some of the info from another site:

---------
EG -- electrovalve grupo -- > group brew solenoid
RE -- resistence electrico (or something like that) -- > heating
element
AE -- alimentare electrovalve -- > boiler fill solenoid
MP -- motor pompa -- > pump motor
L -- dunno (ground/earth, maybe?)
--------

Therefore, my guess is that (old giemme to new gicar) should go something like:
#6 resistenza to F3 res RL1
#7 gruppo to F6 abil erog .... and that's about all I would hazard a guess at.

Original Giemme wiring:

New and old gicar and giemme diagrams:

Thanks!
Geoff

[Ozark_61]

I may have it figured out - but first, if it works, then does it have to be hooked up properly? Even though the machine seems to operate normally, if I have two wires switched, would the unit work (and then I fry something in the controller)? But, if you need to replace an old 115v giemme unit with a new gicar - double check for yourself before trying this at home!
---
EDIT:

Everything was switched around so it was a hassle (relays (ie relay1 = relay3 on the new unit), but I followed the traces and mapped it out and it seems to be working (assuming it would blow up and not work if it's hooked up wrong).

Giemme (should be the correct wire order, looking at the back of the unit, with the 6 spades along the bottom, left to right):
Purple / Black handle, Grey, Red, White, Blue, and Purple

Gicar:
Purple / Black, White, Red, Grey, Blue, and Purple

I assumed the 16 amp relays (k3/rel3 on the giemme board, and go figure, the gicar it's rel1... I almost blew it there) should take the same color, and the 5 amp giemme (k2 or rel2 on the pcb) should go to the 8 amp gicar, and the 10 amp giemme goes to the 12 amp gicar (again, k1/rel1 = rel3 on the gicar).

Therefore (giemme on left, gicar on right):
gruppo = abil erog (grouppo microswitch)
P = pompa RL2 (pump motor)
ev liv = ev cald RL2
resistenza = res RL1 (16 amp relay - boiler heater)
L = c.carichi
1 = F

Other side of the box (the 3 connectors):
Serb = serb (at least that was easy (blue wire) (reservoir sensor)
Ground = ground (green wire)
S.Liv = cald (clear wire)

[LeoZ]

wow.. nice work! couldnt have been easy to figure out!

im bookmarking this thread in case i ever need to replace mine.

notice any difference in the way the machine acts?

[Ozark_61]

Thanks. I would estimate that the auto fill behaves differently. With the new Gicar, it waits longer before auto-filling - which probably doesn't make much difference... but I wonder - what happens to the brew pressure when the auto-fill and group are both engaged simultaneously?
Geoff

[HB]

If the auto-fill engages while pulling a shot on a vibe pump, the brew pressure will drop precipitously.

[Ken Fox]

If the auto-fill engages while pulling a shot on a vibe pump, the brew pressure will drop precipitously.

Are you sure of this, Dan? I have never owned a vibe pump machine with autofill, but I think this would depend on where the OPV is located, assuming one has one and has adjusted the OPV in the machine. If the vibe pump would get up to 14 or 15bar in its unmodified state, and especially if the OPV is located distal to the input solenoid, I think it is very possible that the pressure at the puck would remain unchanged as the pump is capable of producing almost twice as much pressure at the group as one has the OPV set up to deliver. I think this all is going to depend on things such as how the plumbing is designed and configured in a given machine. Testing this would be very easy as all it would require is a PF Manometer; one could start a shot then immediately drain enough water out of the water wand to get the autofill to kick on, then look at how the PF manometer reading changes.

ken

[miKe mcKoffee]

Are you sure of this, Dan? I have never owned a vibe pump machine with autofill, but I think this would depend on where the OPV is located, assuming one has one and has adjusted the OPV in the machine. If the vibe pump would get up to 14 or 15bar in its unmodified state, and especially if the OPV is located distal to the input solenoid, I think it is very possible that the pressure at the puck would remain unchanged as the pump is capable of producing almost twice as much pressure at the group as one has the OPV set up to deliver. I think this all is going to depend on things such as how the plumbing is designed and configured in a given machine. Testing this would be very easy as all it would require is a PF Manometer; one could start a shot then immediately drain enough water out of the water wand to get the autofill to kick on, then look at how the PF manometer reading changes.

ken

Even if the shot pressure didn't dive if auto-fill kicked in during the pull the shot would be ruined anyway since shot temp would likely dive!

[Ken Fox]

Even if the shot pressure didn't dive if auto-fill kicked in during the pull the shot would be ruined anyway since shot temp would likely dive!

That would depend on when the autofill kicked in during the shot, the machine involved, and whether the shot being made was one in a series or if it was being made alone, with no shot immediately following. The autofill kicking in during the shot is more likely to effect the temperature of the NEXT shot than it is to effect the shot in question.

ken

[miKe mcKoffee]

That would depend on when the autofill kicked in during the shot, the machine involved, and whether the shot being made was one in a series or if it was being made alone, with no shot immediately following. The autofill kicking in during the shot is more likely to effect the temperature of the NEXT shot than it is to effect the shot in question.

ken

That would certainly be true with a mammoth boiler like on your Juniors! On the more average sized prosumer ~1.5 boilered HX machines if auto-fill kicked in at or near the start of a shot I'd suspect a goodly temp drop in the shot. Don't know but suspect. But now will have to play and find out, take the top off the Bric', and force a fill right after starting a Thermofilter shot and see what happens. (Since by design it's impossible for the Bric' to auto-fill during an actual shot on it's own. )

[cannonfodder]

On my Isomac, if I am pulling a shot and the auto fill kicks in, the brew pressure drops like a rock, 9 bar to around 6 bar. The pump tone changes dramatically as well. I cannot comment on the temperature. When it happens, I just kill the extraction and sink shot it. Thankfully it only happens once every few hundred shots.

On my Faema, I removed the auto fill solenoid. I have a sight glass so I know where my water level is. I wired in a backlight on the sight glass so it is illuminated when powered on and put a 220v indicator light on the front panel and wired it to the solenoid relay on the level box. That way if the water does go below the probe, the relay will trip the light to remind the operator to hit the manual fill button.

[HB]

If the vibe pump would get up to 14 or 15bar in its unmodified state, and especially if the OPV is located distal to the input solenoid, I think it is very possible that the pressure at the puck would remain unchanged as the pump is capable of producing almost twice as much pressure at the group as one has the OPV set up to deliver.

The 14 or 15bar you refer to is a zero flow. The max pressure a vibe pump can produce drops off dramatically with an increase in flow rate:


Thanks to Eric for the diagram (Flow rate of a rotary pump espresso machine)

When the boiler refill solenoid opens, the water will flow into the boiler in a hurry as it's offering only ~1 bar of resistance, compared to the puck / OPV's ~9 bar.

[LeoZ]

on my giotto premium it drops as well. temp looks like it lowers, but this could just be because the pressure is so much less that the sputter stops.

[Ken Fox]

The 14 or 15bar you refer to is a zero flow. The max pressure a vibe pump can produce drops off dramatically with an increase in flow rate... When the boiler refill solenoid opens, the water will flow into the boiler in a hurry as it's offering only ~1 bar of resistance, compared to the puck / OPV's ~9 bar.

Rather than speculating on this I think it would make more sense to test it, being as it is very amenable to testing and requires equipment that many have. I will attempt to test some of this on my plumbed in rotary machine, realizing that the results aren't necessarily applicable to a vibe machine with autofill.

There are two things to test: (1) effect of autofill on brew temp during the initial and maybe 1 or 2 subsequent shots made at reasonable shotmaking intervals for a particular machine, say one shot per 1.5 or 1 shot per 2 minutes; (2) effect of shot pressure measured by PF manometer before and during autofill engagement.

The equipment needed to accurately observe this would include a Scace Device (preferably) plus datalogger for #1, and a PF manometer for #2. I don't think that a front panel pressure gauge would necessarily be as accurate for this measurement but I could be wrong.

ken

[LeoZ]

Rather than speculating on this I think it would make more sense to test it, being as it is very amenable to testing and requires equipment that many have. I will attempt to test some of this on my plumbed in rotary machine, realizing that the results aren't necessarily applicable to a vibe machine with autofill.

There are two things to test: (1) effect of autofill on brew temp during the initial and maybe 1 or 2 subsequent shots made at reasonable shotmaking intervals for a particular machine, say one shot per 1.5 or 1 shot per 2 minuts; (2) effect of shot pressure measured by PF manometer before and during autofill engagement.

The equipment needed to accurately observe this would include a Scace Device (preferably) plus datalogger for #1, and a PF manometer for #2. I don't think that a front panel pressure gauge would necessarily be as accurate for this measurement but I could be wrong.

ken

why not the flow as i watch it come out of my grouphead? it slows down enough to be seen...

[Ken Fox]

why not the flow as i watch it come out of my grouphead? it slows down enough to be seen...

(1) Your machine may not be like all other machines

(2) The flow rate in a non pressurized situation (like watching water come off a grouphead without a loaded PF or a Scace or somesuch in place) might be different.

I don't claim to be any sort of expert in fluid dynamics, but given that there are many things that are difficult or impossible to test, why not test those things that are easy and straightforward to test? That would give real answers rather than guesses.

ken

[Ken Fox]

This thread has gotten off topic into the issue of the effects of autofill on shot temperatures and pressures in HX Machines. I have started a new thread in this forum on this topic, in order to make this topic more searchable in the future should someone be interested in finding it.

ken