I think I noticed a slight electrical shock on the metal lever of the my Export today - very minimal but I won't use it again until I can do some diagnostics.

Can anyone propose a simple list of connections to test and how to diagnose electrical leakage?

PC

This type of issue can be very hard to diagnose with just a handheld digital meter. An insulation tester or Hy Pot would make quick work of it but if done wrong can actually create a problem that wasn't there before by breaking down insulation. Probably the cheapest way if it has a three prong plug is to plug it into a GFCI fed circuit or get one of the portable GFI units that plug into a known grounded outlet. If there is more than five milliamps flowing outside the hot and neutral wires the unit will trip. Most folks cannot feel that level of current unless they are in a well grounded path.

If you can isolate the machine from ground (earth) with one of the old style plug adapters it may be possible to check the voltage to ground from the machine frame. If there is appreciable voltage it MAY indicate a problem. If you have an analog (needle type) meter it will be a better tool than a digital as the DVM have extremely high input impedance and will indicate phantom voltage in many cases.

Jack, David's advise is spot on; written like a good EE! What's the power system where you're at in Sweden? 220 like most of Europe? Did you replace the HE when you moved there from the US?

Oops being an Iowa fly over country guy I didn't notice the Sweden address. Forgot this is a world wide forum. If 220 volt not sure if you have GFCI available in the portable form but I suspect there are for construction workers and outdoors. Isolating the ground and measuring to a known good earth connection should still yield results but do try to use an analog meter.

Could it have been an electrostatic discharge? Anyway if you suspect current leak please find an electro workshop to have it tested, without the right tools you'll have a hard time finding it, also assuming you lack the knowledge (or you'd already have tested the heaters, which I suspect the problem to be located, if there is one)
The machine has littke components that can fail, worn insulation on the wires, a switch and the heaters as most likely problem imo.

I expect Sweden also has 230 V these days as most of Europe.

peacecup wrote:I think I noticed a slight electrical shock on the metal lever of the my Export today - very minimal but I won't use it again until I can do some diagnostics.

Can anyone propose a simple list of connections to test and how to diagnose electrical leakage?

PC

I suggest having someone qualified to use a multimeter to check it out for you if you are not up on electrical troubleshooting.

First thing I would do is measure the voltage potential of the lever (and the case) relative to ground.
This situation can be deadly.

A static electricity discharge is over almost as soon as it begins and does not persist. A machine case not grounded properly can have a persistant voltage potential present.

Someone with a multimeter will have a hard time finding anything like a current leak, caused by a leaky heater or faulty insulator.
A megger is likely required.

It's been many years since I used a megger, but as I remember it won't damage the insulation either, will it? If not, that's the best instrument to use to find the source of the leak, if there is one.

All the external metalwork,including the lever, of an espresso machine must be earthed. If it's earthed the shock won't be caused by a machine fault; that would trip the RCD (GFI), assuming that you have one!

Earth continuity can be checked easily with a cheap multimeter by connecting one meter test lead to the lever and the other to the earth connection on the plug. The indicated resistance should be less than an ohm. If the machine casing is earthed (and the mains supply earth is satisfactory) then the shock is almost certainly caused by static, as Marcelini suggested.

If you still have doubts about the electrical safety of the machine, you would be best advised to take it to someone with the equipment and experience to diagnose the fault, if there is one, rather than relying on random comments from internet posters.

Hi Jack:

Please let us know your comfort with using a multimeter and your understanding of what's already been said. That will help us guide you to the information needed. Your question implies this is a new situation, because the technique is straightforward. You test the machine unplugged, all wired together through the spades of the power cord, using a multimeter. Then you isolate for the short, testing components separately. To test for a short you see if there is leakage between particular components and the frame. All of that is covered in the Orphan Espresso videos and tech tips, on their site. But to understand fully what Doug and Barb are teaching, you need to know some basics of electrical terminology.

Added: the struck-through text

billt wrote:... is an example of random internet mis-information.

If the case is properly earthed there will be no voltage on the frame.

If there is a short between line and case and the case isn't earthed you won't just get a tingle, you'll get an almighty belt.

If the case is not properly earthed and there is a leakage path from line to the case a multimeter is not an adequate test instrument. You need a tester which operates at a high voltage, as insulation breakdown is often voltage dependent. (Megger is one manufacturer of such instruments and is used as a generic term, but there are many manufacturers.)

Added: Given the correction above, I've deleted references to information that is better explained by people like Bill.