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LR defect triggering earth leakage switch

Hi there,
This morning I changed the water filter of my Londinium R before switching on the machine.
After 10 min of warmup, the electricity in my home went out. It turned out to be the 'aardlekschakelaar' or earth leakage switch
triggering due to something in the LR.
There was a little bit of splashed water on the bottom of the machine, but nothing else. But even after drying everything
the earth leakage switch immediately triggers when I turn on the power.

Can somebody help me track down the problem?

Comments

  • hi jereon
    thank you for your post. can you please clarify something; why does all the power in your house go out when the RCD trips? it is usual to have the wiring in the house divided up into zones so you dont lose all the power in the house when a device trips an RCD

    secondly, you say that 10 minutes passed after you turned the machine on before the RCD tripped. If it is due to you splashing water around under the casing i would expect it to trip instantly

    in the interests of doing the easiest thing first, if it was me i would start by plugging to a different electrical socket, most easily achieved by running an extension lead to another socket and leaving the coffee machine where it is

    my final initial thought would be, have you recently made any change to the 'system'. i.e. have you added a timer between the socket and the plug for the machine, or some kind of energy usage monitoring device, or wemo? has the machine been dropped or the power cable yanked?

    im off to sleep now but ill check back in tomorrow morning as usual

    kind regards

    reiss.
  • No changes to the electrical system at all; the last big change was installing the Londinium :)

    It wasn't the complete house, but our RCD is connected to almost half the outlets in the house.
    Not sure what caused the delay, maybe the splashed water dripped downward during that time.

    I am going to buy a grounded extension cord if needed, but if it a: does trip the RCD again (as I expect it to)
    I still have no idea which part is faulty, and b: if it doesn't I do not know if the housing is safe to touch.

    Is there a way to track down where the shorting happened?
  • hi jeroen

    after you have tried plugging into a socket that is connected to a different RCD - it wouldn't be the first RCD in history that has been a bit too trigger happy - i would unplug the machine from the power supply and remove the top, left, right, and back panels
    i would then take a hair dryer and start moving it around over the wiring to evaporate off any water, starting at the most likely place which is the vertical drop from around the perimeter of the water box, although it may have also travelled along the underside of the top panel from the water box opening and then poured down in another area of the machine
    check also the low water sensor wires that connect to the terminals under the black metal water box carrier - to do this use the torch on your phone to shine light in under the water box from the back & side where the pump is - there is a small gap there. that is also where you should direct the hot air from the hair dryer
    i think it goes without saying, do not be tempted to speed things up with something more powerful like a heat gun as components will be damaged
    after that i would place the machine somewhere where children/others can not meddle with it that is warm and has good air flow (not a cupboard or small room) and leave the panels off for the remainder of the weekend and try it monday after it has dried out
    kind regards
    reiss.
  • whilst i think of it, when the machine is unplugged, take the cover off the Sirai 30A pressure switch and check that it is dry in there, especially if the yellow plug has been removed from the adjustment hole
  • I opened up the machine and let it dry overnight in a warm room. just now I inspected the insides and found no moisture
    at all. the only place were there was some water yesterday was on the bottom just near the pump. It is gone now. Most other parts of the
    inside are even a bit dusty, so certainly no water!

    Still the RCD trips when switching on the LR on every outlet I tested.
    Some part broke down and I would like some help locating it so that I can make coffee again!
  • Try taking the cover off the 30A Sirai pressure switch and checking that the unused third pair of contact terminals have not had the screws vibrate loose and create a short
    Kind regards
    Reiss
  • Hi Jeroen
    How are you getting on?
    Kind regards
    Reiss
  • I opened up the sirai box and found something that looks like soot on the rightmost contact. I attached a photo. Also a
    photo of the inside of the cover where you can clearly see the stain.

    No sign of moisture at all, but this doesn't look right also... :dry:
    image
    image
  • hi jeroen
    and chance of some more images of the pressure switch looking from the other side?
    that burnt material you see there is to be expected as the contacts are basically acting like a spark eroder, i.e. a small amount of material on the contacts is being vapourised each time the contact set closes
    what i am surprised about is that there is not an equal amount of this vapourised material being deposited around both pairs of contacts that are wired in
    so what i am keen to see is that both sets of contacts have wires firmly screwed down onto them as your image suggested that only one pair of contacts is carrying any electrical load
    it is probably also useful at this point to leave the cover off the pressure switch, remove any hands and tools from the machine, plug the machine in and turn it on and observe the action of the switch as it opens and closes
    if it is functioning correctly you should see sparks on the 1st & 3rd pair of contacts and nothing in the middle pair as they are not wired in
    if only one pair is producing a spark/signs of electrical life when opening and closing we have an issue there
    if one of the screws has rattled loose on one of the contacts and fallen into the body of the switch this is likely to be the cause of the electrical short - let the machine run until it trips the RCD - i think there is a good chance you may see some smoke/similar rise up from the switch
    i look forward to some more images
    kind regards
    reiss.
  • I'll try to make some more pictures this evening when I'm back from work. The backside of the Sirai is not really visible because it is flush against the water box enclosure.
    Plugging it in again involves a walk down the stairs to reset the RCD every time I try something with the LR
    so I what am I looking for precisely in the split second it takes to trip the RCD?
  • hi jeroen

    fair enough. let me get a new Sirai heading your way today as its all it can be

    i will send it to the same address as i sent your machine to

    if you would like it sent elsewhere please email me

    if you would like assistance to swap out the Sirai please FaceTime or Skype me when the replacement arrives


    kind regards

    reiss.
  • Thank you,
    I hope it is indeed the Sirai.
    The address is still the same, I already got the shipment advisory from DHL.
  • I received the new pressure switch in good order. Work and other unimportant things kept me from spending
    time with the patient the past two days, I hope/intend to look at the LR again this evening :)

    Can the sirai switch be exchanged as easily as the secondary pressere switch? Any caveats?
  • hi jeroen

    very straight forward, just unscrew a wire on the old pressure switch and secure it in the same place on the new pressure switch

    the only caveat is the standard one when working on any espresso machine boiler and that is to strike the wrench/spanner with a hammer repeatedly to shock the threads apart until you feel it come free

    do not simply put the wrench/spanner on the nut and starting pulling harder and harder or you will twist the boiler, the remedy for which is a new boiler

    it may seem counter intuitive, but it is a critical bit of know-how when loosening or tightening any fittings on the boiler

    when tightening the new fitting turn it down with the spanner until you feel it starting to reach the end of the thread. then strike the spanner once with the hammer; the spanner will turn a long way with almost no resistance. strike the spanner a second time with the hammer and you will feel the drag of the thread arresting the rotation of the spanner. strike the spanner a third time with the hammer and it will come up tight. Stop at that point. A further strike with the hammer on the spanner is likely to rupture the threads.

    kind regards

    reiss.
  • Ai, more complications:
    Before removing the old sirai I tried switching the machine on again. It started to warm up for about a minute (that was a change from the previous switching on trials) but just then it did again trip the RCD and at the same time started dripping from the secondary pressure switch :(
    Quite fast also, about a drop per second. See the attached picture.

    image
    How to proceed? This secondary switch was already replaced last june!
  • hi jeroen

    had you told me it was leaking i would have sent a replacement secondary pressure switch instead

    ill get it on DHL for you later today (friday)

    you will find a thread covering the fitment of the Mater secondary pressure switch here; https://londiniumespresso.com/forum?catid=5&id=1091&view=topic

    kind regards

    reiss.
  • my suggestion is you hold off changing the Sirai until you have changed the Ceme, as it is almost unheard of for the 30A Sirai to give any trouble
  • After the first time the LR shorted I did check the Ceme switch, as I know that that was already a problem once,
    but there was no moisture to be found then.

    At least it is much easier to replace. Is there some way of measuring (I have a simple multimeter) wether this
    really is the cause of the RCD problem?

    How can this part fail twice a year?
  • Just confirmed the ceme secondary pressure switch is causing the short circuit.

    I disconnected the ceme and switched on the LR. It heated up ok and the boiler came to operating pressure and stayed there. No electrical problem occured for more than 10 minutes. Steam and hot water worked fine, so the big Sirai pressure switch works as it should. I then unplugged the machine, reconnected the ceme and turned it back on. Nothing happened until I pulled the lever. This triggers the ceme and after a few seconds the RCD tripped and it started leaking soon after.

    Still a bit puzzled why no water was leaking the first few times that it shorted, but maybe the plastic cover of the Ceme was enough to contain
    the first drops when the leak started.

    Thanks for sending the replacements so quickly. When all is fixed, should I return the new Sirai or just pay it and keeping it in storage when I or another Londinium owner over here needs it?
  • hi jeroen
    it isnt worth the trouble of returning it, hang onto to it
    kind regards
    reiss.
  • I received the new Mater pressure switch.
    After removing the Ceme, I notice that the connectors of the new switch are on the side of the
    switch body.

    It is not possible to screw it in because one of the pipes to the group blocks the
    turn. I attached a picture

    image

    How to proceed?
  • You could temporarily remove the pipe that blocks the turn.
  • I could have done that, but instead I decided to be bold and remove the smaller tube
    where the secondary pressure switch is mounted on:

    image

    It was a bit difficult to unscrew the nuts without putting force on the copper tubes or the boiler itself.
    But I managed to put it back together again with the new Mater switch! :P

    image

    I connected the COM and NC (normally closed) connections just like the Ceme, and
    switched on the LR again. It is warming up now, checking for leaks. None so far, looking good! :)
    Pulling the lever triggers the new switch, so it seems to function properly.

    Is the preset pressure setting the same as that of the ceme? Any change to the adjustment and usage compared to the old
    model?
  • Great solution / workaround!!

    You can feel / observe at what point the lever 'grabs' now, compared to the previous setting/p-stat. In my experience that tells you more than attaching a pressure gauge which could also be possible.
  • Frans Goddijn post=14346 wrote: Great solution / workaround!!

    You can feel / observe at what point the lever 'grabs' now, compared to the previous setting/p-stat. In my experience that tells you more than attaching a pressure gauge which could also be possible.

    Only when beans and grind have been kept the same. I've been using a Bialetti for a week now, and adjusted my grinder accordingly.
    I've kept the setting of the new pressure switch as I received it for now.

    On the positive side: aside from tuning my dose and grind, the LR does work again and I am enjoying my espresso!
  • hi jeroen
    yes, the Mater pressure switches are delivered to us pre-set by the manufacturer at 3.5 bar to give 3.0 bar at the puck
    for medium and lighter roasts this perfect
    for medium and darker roasts that are increasingly more soluble pull the cup from the stream when the lever rises to about 45 degrees above horizontal
    also reduce the pre-infusion time from about 7 seconds to 2-3 seconds, timed from when the pump turns off after you pull the lever down
    kind regards
    reiss.
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