ACS Minima tripping out electricity, me too

Java_avaJ

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Java_avaJ

OK, I just removed the lid and casing. There was no sign of splashing other than some coffee staining on the top of the right most boiler. That had happened because I spilled a very small amount of coffee when I first got the machine (I jumped because I burned myself on the hot casing). But nothing wet, no sign of leaking anywhere.

To make sure I tried everything with paper towel, removed the red push connector on the top of that boiler and checked it was dry, it was. I couldn’t remove the black one opposite without forcing it, so I left it be.

So, no sign of splashing, nothing wet, but when I turn on at the mains the electric fuses immediately blow. Any suggestions for what I might try next?

Java_avaJ

Water spilled out from the portafilter when I started the back-flush, I don’t think it was seated correctly since because the blind basket isn’t so high, I turned it off immediately but might that spillage have got into that cover that’s behind and below the group head? When I take that cover off there are electrical wires connected behind it.

Is it worth taking that mechanism apart, and, if so, can you point me to any diagram or explanation of how to do that?

DavecUK

That’s the vent solenoid, if the wires are touching the case and insulation worn through, it can trip the machine. A symptom of a problem there is a trip as soon as you start a shot, and that’s if a wire is shorted out it gets energised and trips everything out. I am not sure that component will be the problem, but it is removed the same way as a light bulb the fitting is actually a bayonet fitting (brass bit at top) and it’s quite easy just to twist off like a lightbulb, once the wires have been removed of course.

I don’t believe in coincidences, so it’s more than possible something leaked or sprayed when you did the backflush that’s made the machine wet and it’s tripping things out. Perhaps best to wait 24-hours and see if the problem has gone away, and you can switch the machine on without the electrics tripping out. That won’t fix the problem of course, because the reason it tripped during a backflush will still remain.

Java_avaJ

The machine trips the moment I turn electric on at the plug, with the machine itself turned off, so I never get to be able to start a shot. If that’s a clue. Ah but boiler and steam were on. Without those on machine will turn on but turning either boiler on trips

The reason I wondered if the vent solenoid was involved was because it seemed the most obvious part to have got wet because of the spill from the PF. I can’t think why insulation should be worn through on a part that doesn’t move on a machine that’s only 5 months old can you? I think that the vent solenoid only kicks in later in the brew cycle.

Any thoughts on what I can disconnect to isolate the cause? And an explanation of how to disconnect it if you can be bothered.

Thanks Rob

LMSC

Java_avaJ While Dave guides you through, are you using a plug to connect the machine to the wall socket. If yes, you might also want to check the fuse, if you haven’t yet.

DavecUK

Java_avaJ Switching on the machine at the wall without either boiler switched on doesn’t really switch the machine on.

You can of course disconnect the three wires to the solenoid, and see if the machine still trips when a boiler is powered on. Just in case a fault exists in this area. Something I recommend you try next.

The fact that it trips when the switches toggle to the brew boiler or the brew and steam boiler doesn’t really mean much because because if the brew boiler element has gone bad it would trip whether you selected brew boiler only or steam and brew boiler. If if you said it only tripped when selecting steam and brew boiler and didn’t trip when selecting brew boiler, then yes I would agree that the steam boiler element could have gone bad. Toggling this switch either up or down, is what actually switches the machine on.

Tell me, does the pump actually run whenever you switch either boiler on. If the pump is running, then perhaps it’s the pump although I suspect the pump won’t run unless the service boiler needs filling.

Java_avaJ

DavecUK How do you disconnect the three wires from the solenoid, they’re partially in that cutout on the body of the machine itself - do you use long nose pliers, I can’t get my fingers in? Would that trip even though the solenoid doesn’t activate until you switch off?

The pump doesn’t seem to have time to turn on, literally, I turn the electric on and the fuse blows, there’s no delay at all.

I take your point about turning on the boilers, I did turning on only the brew boiler just in case.

LMSC I haven’t checked the fuse in the plug since if that’s gone the main electric fuse wouldn’t blow when I turn the Minima on, since effectively the plug wouldn’t be working.

DavecUK

Yup long nose pliers, be gentle…unplug machine of course.

Java_avaJ

And do you think the solenoid is in the equation since it only kicks in when you end the shot, or is it still part of the circuit? I did seem the electric connections that are closest to the PF overflow I must admit

MediumRoastSteam

Java_avaJ - My understanding is that the solenoid is open by default when not electrified. It’s closed and electrified whilst the shot is running, and, as soon as you end the shot, it opens.

Therefore, it kicks in as soon as you start the shot.

DavecUK

MediumRoastSteam The solenoid is connected directly to the shot switch…it pulls in when the shot starts…and is de energised when the shot stops.

MediumRoastSteam

DavecUK - Thanks. My rationale was correct then :-)

DavecUK

MediumRoastSteam Yes, but I sensed the OP had a need to verify this even though I mentioned it wasn’t energised by simply switching the machine on. You never know though, perhaps something strange is happening.

Java_avaJ

So if the Solenoid is activated on shot start/finish then it isn’t necessarily part of the circuit that activates when the machine turns on and, therefore, Dave’s first thought that it was nothing to do with it might well be correct. However, as Dave adds, “you never know though”.

By the way, DavecUK, what’s an OP?

In the meantime, as extra info, I disconnected one of those white covered cables (there are two) on top of the brew boiler, the smaller boiler, and tried turning it on; it still blew. That was a suggestion from Paolo.

MediumRoastSteam

DavecUK - I wasn’t criticising 😊 - I was just patting myself in the back for having got it right. 😊👍

DavecUK

Java_avaJ Original Poster = OP

DavecUK

Java_avaJ However, as Dave adds, “you never know though”.

You never know….one side of it might be connected, then the switch is a switched live….

Is it an RCD/RCCBO that’s tripping or an MCB? I suspect an RCD or RCCBO

Java_avaJ

So, just come off the phone with Paolo, he got me to remove the black and the blue wire from the solenoid, it didn’t blow, if I connected only the black wire then it blew, if I connected only the blue wire it didn’t blow. Paolo deduces from this that the solenoid is faulty and he’s sending a replacement.

So, I don’t know if that clarifies that although the solenoid is only engaged when the brew starts/stops it still forms part of the circuit that engages when the boilers are turned on.

Java_avaJ

DavecUK I didn’t know what an OP was and so it probably comes as little surprise to you that I have no idea whatsoever what an RCD?RCCBO or an MCB is - I guess a type of circuit board; I’ll go and look in the garage and see if it’ll tell me. I’ll make sure the fuse isn’t triggered so I can shine a light in it’s eyes for questioning 🙃

Just looked on the Niglon site and the picture of an MCB seems to match what we have (M3CU14S/A280LD 4+4 100A Incomer + 2 × 80A-30mA RCDs c/w 8 MCBs (1×40A, 3×32A, 1×16A, 3×6A)

Can you go into more detail about the coil and the thin single nut and exactly what I do? What mucking about will it save, no need to remove the solenoid perhaps?

Java_avaJ

@DavecUK thank you so much for your help and suggestions, I’m learning at lot as I go and most of it from you, not only on this forum but via your videos too, a million thanks. Of course it remains to be seen that changing the solenoid fixes the problem… hopefully it does, I’ve come to depend on good coffee in the morning.

DavecUK

Java_avaJ You will only have to change the coil itself…a 3 minute job…saves all that mucking about. The coil is held in place by a single thin nut…..