Rocket Appartamento Scorching Wire Connectors - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
Nunas
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#11: Post by Nunas »

All good info here. I would only add that spade connectors have two failure points. These are, the crimp and the connection between the male and female parts. Close visual inspection will usually reveal where the worst heating is happening. When making the crimps, use a ratchet type tool, not the cheap hardware store one that look like a pair of pliers. Likewise, use quality connectors, again, not the ones that come in a kit of various sizes for not much $$$. A small wire brush or some fine crocus cloth can be used to clean up the male connectors.

achosid (original poster)
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#12: Post by achosid (original poster) »

I ordered the crimping tool suggested on Stefano's page for the spade connectors I ordered. Fingers crossed this does the job.

DeuxInfuso
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#13: Post by DeuxInfuso »

Two more tips that solved all my hot connector problems forever. After cleaning/polishing the contacts:

1. If needed, use pliers to compress the female spades down (the folded/curly parts of the socket) to make a tighter fit; sometimes they are too loose from the factory. They need to be clean and form a tight/snug connection

2: Critical: to both parts apply silicone grease (Dow molykote 111 or SuperLube or other synthetic grease).

The grease excludes moisture and oxygen, thus prevents the oxidation induced electrical resistance heating that promotes corrosion. This heating at the point of contact between spade and socket causes a thermal-oxidation feedback loop that is the cause of burnt connectors.

If you do this, you will never have a burnt connector again. Some factories apply grease to the connectors, but I think most do not. Also, if you have a traditional vacuum/air valve, these can spray some condensate and steam inside the housing, promoting corrosion here and there.

-Deuxinfuso

achosid (original poster)
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#14: Post by achosid (original poster) »

Thanks so much for the tips everyone.

I have replaced in their entirety three of the four wires that wire into the thermostats:



Two new thermostats, too. I wire brushed and Molykoted all connections, both on the wire terminals and on where they connect, both on the thermostats and the heating element. One black wire went to the loom, which I replaced in its entirety, as well. However, one of the blue wires appears to be where power comes from, as I traced it to here:



It appears to all come out of a plug of some sort. I didn't dig into here: is this wire difficult to replace as well? I put a new terminal on the existing wire and it's running well at the moment.

Nunas
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#15: Post by Nunas »

I wire brushed and Molykoted all connections

Why the Molykote, and which one did you use. All the Molykote with which I'm familiar is grease, which is a lubricant and is non-conductive (IE an insulator, which is the opposite of what one needs in a connection). Chances are that the act of pressing the connections together will remove the Molykote from the connection; so, perhaps no issue.

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Jeff
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#16: Post by Jeff »

Someone up-thread suggested using it as one would use dielectric grease (#13)

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homeburrero
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#17: Post by homeburrero »

achosid wrote:It appears to all come out of a plug of some sort. I didn't dig into here: is this wire difficult to replace as well? I put a new terminal on the existing wire and it's running well at the moment.
That's a DIN plug that powers your solenoid. The two blue wires both connect inside there and provide neutral to the coil and then on to the thermoswitch and element. The coil doesn't draw much current but those blue wires do carry the full neutral current from the element. I wouldn't worry about trying to beef those wires up, but if you really wanted to do that you may want to run a long heavy gauge wire that replaces both those two blue wires all the way to the thermoswitch, and tee off a branch from that wire (from anywhere convenient, and doesn't need to be heavy gauge) just to the solenoid.

To get an idea of how solenoid wires get connected inside a DIN plug you can watch this video: http://www.youtube.com/watch?app=desktop&v=gSdJeoGe6yg
Pat
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Nunas
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#18: Post by Nunas »

Jeff wrote:Someone up-thread suggested using it as one would use dielectric grease (#13)
Thanks. I've been following this thread, but obviously missed post #13 :oops: . Grease should NOT be used in an electrical connection, especially one carrying high current. It is an insulator, not a conductor. Depending on what grease is used, it can even be a fire hazard if the joint heats, which is not uncommon on espresso machine heater circuits. The purpose of dielectric grease is to seal a joint AFTER the connectors are mated. For example, over automotive battery terminals, after they are connected. Its purpose, to keep moisture and dirt out. In any case, in all probability, as I mentioned earlier, mating the connectors probably scraped off the grease, resulting in a good connection, as this has been shown in lab tests to be the case. Still, just because it will be scraped away, does not mean that it should be put there in the first place. The issue, if any, depending on what grease was used and how much, would be down the road if the connection becomes loose and heats.
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JRising
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#19: Post by JRising »

Sorry Alex, but I scrolled through and saw your photo...


You may already know that that kind of wiring was deemed a mistake. On North American machines, it has the full power of the heating circuit being switched on and off by a tiny relay on the powerboard that is barely rated to handle it. If you search the Appartamento posts in these threads, you'll see the "upgrade" spoken of time and again (Probably by me, I'm kind of annoying)...

You obviously have the ability to manufacture your own good 14 gauge wires with good connectors, so if you'd like to message me with your email address, I can send you Rocket's little instruction page for doing the upgrade. (It will require a new 16 amp Mater or Campini pressostat if your current pressostat is less than 15 amps). You can read the pressostat's amperage on the side of it. This "upgrade" stresses your relatively inexpensive pressostat instead of stressing the expensive powerboard. I believe it is a good idea.

This goes for anyone who wants a copy of Rocket's little how-to instruction page.

achosid (original poster)
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#20: Post by achosid (original poster) »

JRising wrote:Sorry Alex, but I scrolled through and saw your photo...
image

You may already know that that kind of wiring was deemed a mistake. On North American machines, it has the full power of the heating circuit being switched on and off by a tiny relay on the powerboard that is barely rated to handle it. If you search the Appartamento posts in these threads, you'll see the "upgrade" spoken of time and again (Probably by me, I'm kind of annoying)...

You obviously have the ability to manufacture your own good 14 gauge wires with good connectors, so if you'd like to message me with your email address, I can send you Rocket's little instruction page for doing the upgrade. (It will require a new 16 amp Mater or Campini pressostat if your current pressostat is less than 15 amps). You can read the pressostat's amperage on the side of it. This "upgrade" stresses your relatively inexpensive pressostat instead of stressing the expensive powerboard. I believe it is a good idea.

This goes for anyone who wants a copy of Rocket's little how-to instruction page.
Thanks so much for this. I'll be fixing my machine in line with this.
Nunas wrote:Thanks. I've been following this thread, but obviously missed post #13 :oops: . Grease should NOT be used in an electrical connection, especially one carrying high current. It is an insulator, not a conductor. Depending on what grease is used, it can even be a fire hazard if the joint heats, which is not uncommon on espresso machine heater circuits. The purpose of dielectric grease is to seal a joint AFTER the connectors are mated. For example, over automotive battery terminals, after they are connected. Its purpose, to keep moisture and dirt out. In any case, in all probability, as I mentioned earlier, mating the connectors probably scraped off the grease, resulting in a good connection, as this has been shown in lab tests to be the case. Still, just because it will be scraped away, does not mean that it should be put there in the first place. The issue, if any, depending on what grease was used and how much, would be down the road if the connection becomes loose and heats.
It was Molykote 111, if that changes anything. It's running fine as-is, so I'm a bit hesitant to pull the terminals and clean them off if I don't have to and stress them out in any way.
homeburrero wrote:That's a DIN plug that powers your solenoid. The two blue wires both connect inside there and provide neutral to the coil and then on to the thermoswitch and element. The coil doesn't draw much current but those blue wires do carry the full neutral current from the element. I wouldn't worry about trying to beef those wires up, but if you really wanted to do that you may want to run a long heavy gauge wire that replaces both those two blue wires all the way to the thermoswitch, and tee off a branch from that wire (from anywhere convenient, and doesn't need to be heavy gauge) just to the solenoid.

To get an idea of how solenoid wires get connected inside a DIN plug you can watch this video: video
I'm going to skip re-wiring this one and cross my fingers that I'm good to go here. Are there any other wires in this machine that you think are a must-replace given my previous issues?