Used espresso machine has sticky wire insulation - should it be replaced?

[kwksilver]

Hi guys,
just started taking the freshly delivered M30 apart. She seems in pretty good condition given her age.
in the electronic box under the drip tray I found one blue wire going from the black round (coil?) thing out.
This wire is 'gooey' for lack of a better word. The plastic around it is sticky and very soft. it is dissolving my fingers were blue after touching it. The machine does not show electrical burn or damage. I have not plugged her in, nor do I plan on doing that until I have given her a deep physical.
Any idea what causes this softness at room temp? Should that be replaced?

(I get how high currents produce heat and melt insulation when the wire is live, but it clearly hasn't been live in the past....weeks)


Regards,
Felix

PS: I promise detailed pictures of everything internal starting tomorrow, the camera is at the fiancee's.

[Randy G.]

....
This wire is 'gooey' for lack of a better word. The plastic around it is sticky and very soft. it is dissolving my fingers were blue after touching it.

Sounds like the wire was exposed to an environment or chemical which reacted with the insulation. If that is the only wire in there which is reacting that way, I would replace it as it will only get worse. maybe ozone or a petrochemical used to clean it out that softened it. If it was just heat, then it would have hardened when cooled. Examine the rest of the wires to be sure that none of the others are getting softer.

[kwksilver]

there are a lot of wires in proximity and it is literally the only one suffering from this. that puzzles me.
I agree with your petrochemical idea.
Thanks for your help.
Felix

[Mike_]

there are a lot of wires in proximity and it is literally the only one suffering from this. that puzzles me.
I agree with your petrochemical idea.
Thanks for your help.
Felix

At one time that particular wire may have been passing excessive current, which caused it to heat up and break down the insulation. Certainly the wire should be suspect and more importantly what caused the problem to happen in the first place.

Ideally the wire should be replaced with the same size and same insulation rating or higher. You might be able to get away with wrapping it with electrical tape, but I would only do that if it's entirely impractical to replace the wire.

[kwksilver]

I am certainly poor, but not too cheap to replace a wire; that seems like saving in the wrong place.

Do I understand you correctly in saying that I should not use a heavier gauge wire in the same place? (I presume it is to keep resistance about the same.)
I will be sure to buy the best grade insulated wire.(I don't know anything about it but I bet they are rated by current, temperature or other things of the sort..the insulations that is.)

(I found a second also blue wire with exactly the same phenomenon. i think someone replaced those with inferior wiring at some point maybe?)

Felix

[cannonfodder]

You will want to pay particular attention to the temperature rating of the wire/insulation. Most of what you get at places like RadioShack will not take the heat. The insulation will harden and crumble over time.

[JimG]

At a minimum, use:

1). AWM hookup wire (Appliance Wire Material)
2). stranded copper conductors, with tin or silver coating
3). UL 1015 spec (105C, 600V)
4). Crimp connectors that have both a wire crimp and an insulation crimp (for strain relief)

Surprisingly, small spools of wire with these spec's is available at Lowes. Probably available at auto parts stores, too.

Jim

[kwksilver]

your detailed specs seem like that is exactly what i need. Everything I replace is supposed to be an over-engineering response to the problem of the past. I think you helped me go that direction.
Regards,
Felix

[DavidMLewis]

Probably available at auto parts stores, too.

That may be easier to find. Small spools are indeed sold, in different colors, in auto parts stores, labeled "primary wire" usually. Since they're designed for under-hood temperatures you can feel safe in using them for this application, and they're generally 16 gauge, which will handle any current you're likely to see in your machine. Be sure to get an actual crimp tool if you don't have one, and ask someone to show you how to use it if you're not familiar. A crimped joint forms a gas-tight cold weld, and is actually better than a soldered one, but only if the tool is used properly.

Best,
David

[ira]

Personally I've never seen wire in an auto parts store I'd trust under the hood of a car, let alone inside an espresso machine. Modern cars use S, G or TXL wire which is a much more heat resistant wire, 125C, the hook-up wire at most auto parts stores is only rated 176F or so, enough if you're very careful routing it, but not nearly enough if anything goes wrong. My Brutus is wired with Fiberglass wrapped silicon insulated wire which is probably good to 400F and would seem like a lot better choice if you can find it.

You can get 25' pieces of SXL wire and high temp terminals at http://www.wiringproducts.com. Not to say you can't do better but for some reason finding high temp wire is always difficult. These people sell really high temp wire, http://www.infraredheaters.com/wires.htm, but they have a $25 minimum and the wire is about $1 per foot.

Ira

[kwksilver]

Thank you VERY much for the detailed info guys. I ended up finding wire that stated it was rated at 105c AWM at HOME DESPOT of all places.... (fair enough)

it was dirt cheap and 10 gauge. I did some more investigating, and have decided to post all future questions within my la cimbali M30 rebuild thread for everyone's convenience.



The two sticky blue wires come from that transformer there. i opened the transformer and found myself utterly intimidated by the prospect of having to open the plastic covering around the round coil to detach the wiring there. until I know exactly what to do and have done my homework on these transformers I am stuck with wire ready to go. if that wire wasn't factory, then I am impressed by whoever managed to get it into the transformer like that. (I will try to take a picture of it this weekend.)


Regards,
Felix