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Permalink Reply by Scott on March 16, 2012 at 10:14am

Is it connected to the mains water?  It could be the pump relay in the brain. Or a bad capacitor on the pump.  Or just a bad electrical connection between the two. Did you confirm the voltage where the machine was previously installed and match that voltage at your house (needs to be +/- 5%); or you could end up with a fried brain. I.E. - if the voltage at the location where the machine was previously installed was 240 and your house is 208, it's going to have problems.  IT DOES NOT MATTER WHAT THE RATING PLATE SAYS ON THE SIDE OF THE MACHINE. If it was installed and running for longer then two years prior at a particular voltage, you need to match the supply voltage at the new location.  This has to do with the 12v power supply in the brain ( which you could just have rebuilt for peace of mind).

 

The resting pressure on the machine is unimportant, though it should not exceed 15 bar.  On a non PID machine you will see quite a swing in resting pressure.  The pressure should go to 9 bar when pulling a shot.  That's it. 

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Permalink Reply by Hugo on March 16, 2012 at 3:11pm

Thanks scott.

 

I think the power in Australia is +10% -6%. It's foreseeable then that the power has shifted. By "brain" you mean the CPU? I might look into getting it reprogrammed. I'll definitely look into getting a new pump cap since they're fairly cheap and easy

 

Unfortunately the previous owner has disappeared after I pointed out a missing part (that was making the machine pretty much non-functional) and asked him to compensate me the $40 for it

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Permalink Reply by Hugo on March 16, 2012 at 3:37pm

Dammit, Just went to turn the machine on for the morn. It was working 8 hours ago when I went to sleep, but now the pump motor is shorting regardless of whether or not it's connected to the machine. 

 

Every night I turn off the mains power to the machine (switch it off at the wall) but leave the mains power to the pump on. Problem? 

 

Something is happening overnight which isn't happening during the day  

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Permalink Reply by Brady on March 17, 2012 at 5:42am

Hi Hugo,

Sorry to say that your problem has not been solved - it is simply teasing you and giving you a chance to diagnose and repair before it really goes wrong (and potentially takes more stuff with it). "Pump electrical gremlin" sounds like "CPU failure" to me... though I could be wrong.

Since we're discussing possibly major repairs, it would be a good idea to call in a tech to take a look. All of the parts we're discussing are expensive.

Note that the motor and pump head are two separate pieces, usually sold separately. I find pump head issues far more common than motor-related issues. Also, motor-related issues are more often capacitor problems. Capacitors are cheap, pumps less so, motors even less so. I rarely replace the whole motor+pump - the only times I've done so is when a pump seal has failed and trashed the motor output shaft bearing.

On the other question - for the most part, a pump is a pump when it comes to espresso machines. There are 2 main manufacturers and 2 main styles used by most espresso machines. Fluid-o-tech and Procon mount and function the same way. Some bigger (3+ group) machines use a slightly larger-bodied pump with a strainer, though I've not seen this be a universal rule. The fact that your pump has a Wega sticker on it is probably not the issue. If it fit, it should work. The fact that the machine has a Wega pump does raise some questions though.

The check valve on a La Marzocco is supposed to be mounted to the pump. If it wasn't swapped when the pump was replaced then your machine doesn't have one. This is a code issue in the US, but also changes the pump's operating environment. I'm not sure that this is a huge issue (I've had some techs tell me it was no big deal), but I like to keep machines in the configuration that the manufacturer recommends.

The fact that your machine pressure was running so high suggests the possibility that the bypass may not be working correctly. This is common with older pumps... and can be fixed assuming that the rest of the pump is ok.

The whole "leaving power on to the pump, but not to the machine" thing has me very confused. The pump is supposed to receive power from the machine - the cord running into the machine and leads be wired in to a block inside the machine - no external power. Is this how yours is, or is it connected in some other way?

Also, your motor should be elevated off of the floor - perhaps on a concrete block or shelf. This keeps it out of the reach of mops and isolates it some from floor-level moisture.

Verify that the machine has been hooked up correctly, call in a tech, and post back with what you find.

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Permalink Reply by Hugo on March 17, 2012 at 6:16am

Whoa, informative post, thanks!

 

For now I can only give a short response because it's bedtime. I'll update in the morning.

 

Firstly- to correct a mistake in my post. I meant to say that I keep the water to the pump left on overnight but I turn off the machine at the wall. My thought was that perhaps having mains water pressure loading the pump for 8+ hours could be straining the motor somehow.

 

Sorry that I keep saying "pump" when I really mean "pump motor". It only helps to confuse the situation.

 

When the pump/motor is shorting out the machine, I often try to plug the pump/motor directly into mains power to see what happens. Without exception, it shorts out the mains power too. This suggests to me that the shorting problem is the motor itself, and has nothing to do with the machine.The pump/motor is raised off the ground, but I just went to check on it and it's got a thin coating of water on it (it's raining all day). I'm getting pretty sure that the shorting problem is just from water getting in. For now I'll waterproof it better and I'll replace the cap too because it's cheap and probs pretty old.

 

What remains a mystery is why it was decreasing pressure while brewing, instead of going up to 9bar. That resolved itself mysteriously, but clearly something is going on with it. 

 

Tomorrow morning I'll check out the things that you mentioned and will report back with any findings.  

 

Thanks heaps. I literally said "whoa" out loud when I saw your post 

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Permalink Reply by Brady on March 17, 2012 at 6:55am

Yeah, that's probably the issue. Motors don't like moisture.

Be careful handling that capacitor (they can hold a substantial charge, and should always be discharged before handling) and make sure that you match the capacitance. I wouldn't worry about replacing it unless there is a problem though. If you happen to have a multimeter that measures capacitance you can always check it against original value - if it is still within a couple of percent of nominal it is fine.

Forgot to mention - check to make sure your water supply is adequate. Any chance your filter needs to be changed?

Good luck.

Hugo said:

...When the pump/motor is shorting out the machine, I often try to plug the pump/motor directly into mains power to see what happens. Without exception, it shorts out the mains power too. This suggests to me that the shorting problem is the motor itself, and has nothing to do with the machine.The pump/motor is raised off the ground, but I just went to check on it and it's got a thin coating of water on it (it's raining all day). I'm getting pretty sure that the shorting problem is just from water getting in. For now I'll waterproof it better and I'll replace the cap too because it's cheap and probs pretty old.

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Permalink Reply by Scott on March 17, 2012 at 7:47am

Hugo - Since the pump isn't physically mounted in the machine, and therefor easy to move, you might want to take it to an electrical shop ( if one is available locally) to have checked out. Taking it in yourself may save you some money over having someone come on site. Or, if you feel confortable doing it youself, just post all the information labled on the pump (or a couple of pictures of it) and we can give you the values needed to test it with a multi meter.

As to the CPU (brain) don't get to worried over it yet. I mentioned the issue with voltage as most people are unaware that the voltage can vary from place to place, at least here in the the US ( and in Europe too). Austrailia might be a different story. The point being that while the machine is 220v, the logic portion of the CPU is like that of other computers in that it is 12v. therefore there is a power assembly on the board that stepdowns the 220v to 12v and rectifies it to DC. It's this power assembly the tends to fail when a machine is move from one location to another.
The other thing that can be giving you issue is the pump relay, which is most likely soldered to the board.
All of this can be repaired by a competent electronics shop. We used to rebuild all of our LM CPUs.

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Permalink Reply by Scott on March 17, 2012 at 7:54am

Also, we have a product over here called Quick Dry Electrical Contact Cleaner, made by CRC. I would suggest getting that, or a substitute product, and completely spray down the de-energized motor. Get it soaking wet with this and then let it dry for ten minutes. It's magic. I would do that before I did any testing.

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Permalink Reply by Hugo on March 18, 2012 at 2:02am

Same old story today. Motor was dead this morn but after being disconnected and taken inside to dry for a few hours it's working again. Either it was just wet, or it's some coincidence coming from disconnected the water in/out and draining the pump itself.

 

have a multimeter and are fairly technically competent. It seems that the motor is a RPM s.p.a 01-18-T80. the RPM website is fairly useless. The pump is a fluid-o-tech p204.

 

I have contact cleaner somewhere If I can find it I'll do that. I never would've thought of that!

 

Here's a gallery of labels of the motor and pump. The pump is actually made by fluid-o-tech. I guess it was once on a Wega machine, hence the label.

 

I'll see if it works in the morn and will keep a keen eye on it. Happy to do any testing if anyone has suggestions

 

Thanks again

 

Hugo

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Permalink Reply by Brady on March 18, 2012 at 4:57am

Looks like a standard Fluid-o-tech and RPM combo to me. Your check valve is missing though, and ought to be replaced. It belongs on the output side of the pump.

Any chance your meter has a capacitance setting? Many don't (including the one I used to use). If it has that, check your capacitor. Or just replace it.

I think moisture is your issue. I had a house with a damp garage for a couple of years and lost a couple of power tools due to motor failure. Can you relocate the motor to a drier spot, perhaps closer to the machine which is hopefully in a less damp place?

Oh... leaving the water on to the machine when powered off is not an issue.

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Permalink Reply by Hugo on March 18, 2012 at 5:51am

Yup my multimeter has a capacitance measure (and other cool stuff too- I bought the most expensive one :D) I'll measure that in the morning. The problem with being in a completely different timezone is that I get all of your advice as I'm going to bed!

 

Humourousky I was planning to go to a plumbing place tomorrow to get a one-way-valve for another part of my water supply system. I'll get the check valve at the same time.

 

I still can't figure what was causing the pressure to drop during brewing that one day. It seems as though for some reason the pump was not powering on when it should. Either this is something related to the moisture (not sure what would cause that though, without shorting out) or a more serious problem in the CPU or relays.

 

For now, wish me luck.

 

I clay bar cleaned and waxed her today, so she owes me a few days of peak performance 

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