I purchased a nearly mint condition Gaggia Classic espressio machine last week from a couple that had only used it 4-5 times in the nearly 20 years they have owned it. This unit is 120V 60HZ 1425W, two pronged, and was manufactured in 1998, but the design and components used in the unit have not changed in this time period (wiring has changed as you will see). On the second day of using it, I noticed that I was recieving a mild electronic shock to my forarm when I was steaming milk (felt like I was running my forarm against something sharp), the stainless steel steam wand touching the stainless steel milk carafe, which in turn was in my hand, and my forarm (same arm) was bushing against the stainless steel door on my fridge. I could not find my volt meter to figure out how big of a leak was occuring, but I could find my electric fence tester, which has a small light bulb to check that an electric fence is live. I confirmed it was the espresso machine and not my fridge first, then I opened the top of the espresso machine and checked to see if there was any particular wire, or electronic that might be leaking into the boiler, and in turn, steam wand. Nothing stood out to me, so I checked a Gaggia forum, and found one other person with a unit about the same age as mine, theirs was doing something similar, and they took it to a small appliance electrician that discovered their line and neutral wires were switched from what they should be, they switched them, and they no longer had a current leak.
This lead me to carefuly look at how my unit was wired, compared to the factory wiring diagram, and I found they have changed their wiring layout compared to how mine is, but there are many similaries. One similarity is that the initial two wires (line and neutral) that lead from the plug socket, go to the same initial locations in the machine, but were switched in my unit. Meaning the neutral wire was going to the on/off switch, and the line wire was going to the thermo cut-off fuse. Using some protective gear, I switched the line and neutral wires at the plug and functioned tested the machine, everything works, and I no longer have a current leak.
My question is this, why did the machine function normally with reverse current flow? And why did switching the current flow resolve the current leak?
I have attached the factory wiring diagram(ev00), the wiring diagram of my unit currently after switching the line and neutral wires (1998), and a photo from above the unit to show what I am working with (I accidently cropped out the plug socket attachments, but they are the grey and blue wire at the top of the image next to the black hose).
*edited for clarity
This lead me to carefuly look at how my unit was wired, compared to the factory wiring diagram, and I found they have changed their wiring layout compared to how mine is, but there are many similaries. One similarity is that the initial two wires (line and neutral) that lead from the plug socket, go to the same initial locations in the machine, but were switched in my unit. Meaning the neutral wire was going to the on/off switch, and the line wire was going to the thermo cut-off fuse. Using some protective gear, I switched the line and neutral wires at the plug and functioned tested the machine, everything works, and I no longer have a current leak.
My question is this, why did the machine function normally with reverse current flow? And why did switching the current flow resolve the current leak?
I have attached the factory wiring diagram(ev00), the wiring diagram of my unit currently after switching the line and neutral wires (1998), and a photo from above the unit to show what I am working with (I accidently cropped out the plug socket attachments, but they are the grey and blue wire at the top of the image next to the black hose).
*edited for clarity
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