Hi,



I'm hoping people may have some advice or thoughts on a recent problem I've experienced with my expobar elegance compact one group. It has been fully descaled approx 1 year ago and has run on mostly filtered water. Used lightly over that time. Run with no problems.



I went to use it about a week ago - pulled first shot fine. Second shot the volumetric dosing started to play up. I use the manual on off button when pulling shots. I pressed it and it ran for about 3 seconds before turning off. This continued to happen. Turned the machine off.



Returned later and turned it on. Ran as per normal for a few days before I turned it on in the morning and the volumetric dosing was not working at all. It doesn't look like the auto fill is clicking on now either (drained a bit of water through hot water tap and no refill).



Has to be either the volumetric dosing (brain box) or something to do with the flow meter, or maybe rotary pump?



Any thoughts or ideas on how to trouble shoot would be greatly appreciated.



Thanks,



John

If you are having problems with volumetric dosing, the first thing I would look at is the flow meter. Remove the three screws, take off the cap and lightly spin the plastic "catspaw" found within....it should rotate freely. Often a small object/piece of scale will get stuck in there. Clean the housing internally and the catspaw, reassemble and try running the machine. While a stuck catspaw is the usual culprit with flowmeter problems, it could be an electrical issue with them also. There are three electrical connections on the top of the flowmeter. They are marked on the housing of the flowmeter field:
"+" corresponds to the DC power supply and should always read 16 - 22 volts DC
"_" corresponds to the ground or earth wire. It should be connected directly to the ring terminal and attached to the housing of the flowmeter. This should always read 0 volts (note: might go back to ground at the Gicar programmer or be connected directly to the flow meter body).
"0" corresponds to the output signal in the control box. This terminal will switch rapidly from 18 to 0 volts when the group is activated.
To test the flowmeter, disconnect the red and white wires and measure the terminals (not the wires) of the flow meter field. A reading of 1.8 to 2.4k ohms is acceptable. A reading of 0 ohms indicates a problem requiring replacement of the sensor.

Let me know how that works out.

Lars

Thanks for the quick and detailed response.

We took apart the flowmeter:
The impeller is spinning freely
Attached is an image of the flowmeter terminal resistance reading. Would this suggest the cap needs to be replaced.

Can you suggest any other testin to confirm this.

Thanks again

John

An update:

I spoke to the Expobar tech and they seem to think that it's the brain box, as it would be providing the power to the flow meter (measured 3V DC between the '+' terminal and GND).

Attached is two images, the 1st showing the circuit of the Gicar 1d5e GRCZ NKP S10 9.5.28.30v00NEW.



The second picture is of the back of the PCB. Item #1 is what I think is the primary winding of the transformer, this measures no continuity with the DMM. Item #2 is what I'm unsure about. I think (based on nothing) that these are the connections for the transformer secondary. These do have continuity with the DMM.



Am I measuring the correct points? If so, then TR1 would be shorted and requiring replacement.

I also checked the coils of R1, R2 & R3 and they all show around ~500ohms. Which seems ok?

Any other ideas?

Thanks!

To answer the first of your two recent posts, based upon where you have chosen to check continuity, the impedance should be approximately 100+K ohms and your reading seems to be about 40 ohms which is approximating a short circuit. Because of the fact that there are diodes and capacitors in the circuit, a pure resistance measurement where you have taken it is not possible.

i should have first asked: while installed and operational, i.e, when water was flowing through the hydraulic circuitry, was the yellow light on and blinking on and off? If so this would indicate that the impeller is turning as water passes through the thing and the circuitry is operating properly. You measured the impedance when disconnected.... did you try measuring the voltage I suggested in my first reply while it was connected? That is the definitive test.

As to your second question and the Expobar tech's advice, one would think he should know. You didn't mention that you are experiencing no voltage at the positive terminal of the flowmeter. HOWEVER, assuming it is a Gicar flowmeter (the one that comes with the machine when new) they are rated from 4.5v to 24vdc. In my experience they typically run between in the high teens....3vdc sounds awfully low.

The other thing is that Gicar controllers fail at a small fraction of the frequency that the flowmeters do. The entire flowmeter is available in the USA at least) for about $70 retail and you can also purchase just the cover with the circuitry for half that. The Expobar PN for the lid/cover is 60102040 but you can buy them many places. It never hurts to have one around. On the other hand, the Gicar programmer costs about $250 or more here. Finally, if the impedance where you measured it is truly only 40 ohms, then your flowmeter is shot. Lest ye be doubters, i have attached a photo taken showing the impedance/resistance of a brand new out-of-the-box flowmeter. Note the scale, 200Kohms and the 115 Kohms reading....that's a wee bit more than the 40 ohms you measured on yours, n'est ce pas?

Just thinking about this further as I think about shutting down for the night; I know I may be sounding overly confident that your flow meter is the (only) problem but I hope not as it's an easy fix compared to the reasonable alternatives. The main reason the flow meters go bad (from an electrical perspective) so often in Expobars is that they are located almost directly under the boiler ( I assume you have a 6 L boiler). The problem is that the vacuum breaker valves on the top of the horizontally mounted boilers have a tendency to go bad ( o-ring deteriorates) and they spew water all over the boiler and it runs down onto and sometimes into the flow meter. I've seen commercial field techs put small plastic bags over the flow meters in commercial units where they aren't around to replace the o-rings in the vacuum valves on a regular basis. FYI. Keeping that o-ring fresh and lubricated will also help keep a newly polished boiler looking great for a long time.

Hi Larz, I have been helping out 10ett with this problem in person and was posting from his account. Will try answer some questions below.

Larz wrote:To answer the first of your two recent posts, based upon where you have chosen to check continuity, the impedance should be approximately 100+K ohms and your reading seems to be about 40 ohms which is approximating a short circuit. Because of the fact that there are diodes and capacitors in the circuit, a pure resistance measurement where you have taken it is not possible.

Agreed, It seems that something isn't right with the flowmeter. Should I have checked resistance elsewhere?

i should have first asked: while installed and operational, i.e, when water was flowing through the hydraulic circuitry, was the yellow light on and blinking on and off? If so this would indicate that the impeller is turning as water passes through the thing and the circuitry is operating properly. You measured the impedance when disconnected.... did you try measuring the voltage I suggested in my first reply while it was connected? That is the definitive test.

To be honest, the machine was always closed up when things were working so can't answer for sure, however, after testing the flowmeter resistance, we put things back together and the yellow light was on. Buttons/controls were still not responding so unable to say if flashing. I did measure the volts (at the brain box side of the wire), as there is no way to access the terminals once connected to the cap of flowmeter. I measured 3Vdc between positive and negative terminals on the brain box side (see the picture of the Gicar circuit where connections are: +; Out; -).

As to your second question and the Expobar tech's advice, one would think he should know. You didn't mention that you are experiencing no voltage at the positive terminal of the flowmeter. HOWEVER, assuming it is a Gicar flowmeter (the one that comes with the machine when new) they are rated from 4.5v to 24vdc. In my experience they typically run between in the high teens....3vdc sounds awfully low.

The tech was only on the phone, he didn't even discuss the flow meter and thought of the brain box straight away. His thoughts were either the relays or the transformer failure (hence my 2nd post regarding TR1 failure). Since the DC Volts is generated from the brain box, if that was faulty, wouldn't that give a false reading at the connections?

The other thing is that Gicar controllers fail at a small fraction of the frequency that the flowmeters do. The entire flowmeter is available in the USA at least) for about $70 retail and you can also purchase just the cover with the circuitry for half that. The Expobar PN for the lid/cover is 60102040 but you can buy them many places. It never hurts to have one around. On the other hand, the Gicar programmer costs about $250 or more here. Finally, if the impedance where you measured it is truly only 40 ohms, then your flowmeter is shot. Lest ye be doubters, i have attached a photo taken showing the impedance/resistance of a brand new out-of-the-box flowmeter. Note the scale, 200Kohms and the 115 Kohms reading....that's a wee bit more than the 40 ohms you measured on yours, n'est ce pas? <img>

Agreed. Will probably order a new top of the flowmeter since it's quite cheap and try that first.

Larz wrote:Just thinking about this further as I think about shutting down for the night; I know I may be sounding overly confident that your flow meter is the (only) problem but I hope not as it's an easy fix compared to the reasonable alternatives. The main reason the flow meters go bad (from an electrical perspective) so often in Expobars is that they are located almost directly under the boiler ( I assume you have a 6 L boiler). The problem is that the vacuum breaker valves on the top of the horizontally mounted boilers have a tendency to go bad ( o-ring deteriorates) and they spew water all over the boiler and it runs down onto and sometimes into the flow meter. I've seen commercial field techs put small plastic bags over the flow meters in commercial units where they aren't around to replace the o-rings in the vacuum valves on a regular basis. FYI. Keeping that o-ring fresh and lubricated will also help keep a newly polished boiler looking great for a long time.

Cheers Yes, this is the 6L model. Machine was recently stripped down and rebuild by 10ett. I think he replaced all the O-Rings etc etc.

Eager to hear other thoughts. Would a failed flow meter mean no response from the buttons? We also disconnected the level probe to try trick the brain box to auto-fill, but nothing happened. Hence why my thoughts tend to lean towards the brain box. Potentially if it is the TR1, then when it failed, it may have taken out the flow meter too? Again, speculation.

Tim

Hey Tim,

Without getting into detail (may be tough for me...i seldom use one word when 3 or 4 will do ): I suggest you forget about the Gicar controller for the time being and try and determine (or eliminate) the flowmeter as a/the source of the problem. Remember what the purpose of the flowmeter is, at its most basic level: to indicate that water if flowing through the hydraulic circuitry and to tell the Gicar this is so, so the Gicar can regulate the volume being dispensed. If the yellow light is on, you are getting voltage to the flowmeter. If you can get water running through the system even for a minute or two, the yellow light should be pulsing if the flowmeter is working correctly. The impeller has two small magnets inside which turn and operate with the circuitry/sensor in the top of the flowmeter. That impeller turns as a result of water flowing through it when a button on the Gicar is pressed; the flowmeter then generates a square wave voltage between the "0" and "-" terminal which causes the light/LED to flash on and off (the purpose of the LED is purely to troubleshoot as you are doing now, so use it! ) and sends this signal back to the Gicar which then controls flow based on how you have it programmed (or as was programmed at the factory...your decision). So the pulsing yellow LED is key. When I first worked on an Expobar years ago I received good advice both from the factory engineer in Expobar near Valencia ( Miquel Sanchez Llopis), as well as from a head tech guy from Expobar HQ in England named Lee Rushton, in case you need to look them up at some point. I swore and argued that I had a bad Gicar controller and I was looking for internal schematics so I could test and replace internal components. They both said no, I had a bad flowmeter. They told me to spin the impeller while wired up and see if I could get the LED to pulse on and off. (You don't have to but I found it easiest/most accurate to remove they flowmeter but leave the wiring intact so I could get into the body of the flowmeter and spin the impeller manually.) I did that but got no pulse, replaced the cap with a new one and voila, all my "Gicar Controller problems" went away. I used this experience successfully ever since.

Now, despite having already said how reluctant I am to suggest you focus on the Gicar until you resolve the flowmeter issue, the voltage at the + terminal of the flowmeter will be about 22VDC to ground, give or take. THIS I have confirmed with the Expobar engineer. But for the time being assume you are getting adequate voltage since the LED is lit, and focus in the meter. Troubleshooting a Gicar electrically can be tricky since output voltages and current can be dependent upon inputs the Gicar is or isn't getting elsewhere.

Do you have the basic Gicar iD5e programming instructions? Do know how to use the Gicar, i.e., put into programming mode and tell it what to make the individual buttons do, etc? Do you have the exploded diagrams and parts manuals for your machine? If not, PM me and give me your email and I'll send them to you.

Lars

Also, in my rush, besides ignoring some of your specific questions , i forgot to ask if you have put the controller in Program mode ("*" button on the right...hold for about 7 seconds or until all the other lights on the keypad light up) and tried setting the volumes on the other buttons?? Are you still unable to even get some water flowing through the thing by pushing any button?