Compound of copper and aluminum. A trick that electricians are in no hurry to talk about

Hello, friends.

For those who are waiting for some provocations, I will say right away - they will not be. Only practical observations and advice.

Direct twisting of copper and aluminum is not allowed. We are not discussing this. But even the "allowed" PUE connections sometimes fail. More than once I had to see melted terminals in the junction box and burnt wires on the bolted connection.

Why do contacts still burn out?

It usually goes something like this:

In the old house, the switch or the socket stopped working. An electrician comes, builds up an aluminum wire with a copper one using a terminal and basta - the work is over. But he doesn't say a word about screw terminals being serviced connections. They need to be tightened from time to time.

Then it goes like this:

The grandmother turns on the electric stove and the washing machine at the same time on the "boil" mode. The wiring at this moment is working at full load. It can withstand, of course, but aluminum, as electricians say, “flows”. It "flows" even without overloads, but it takes much more time.

As a result, the connection is weakened. The contact gets worse. It starts to warm up and burns out.

How to avoid fire

In theory, screw connections must be serviced. Dot. But as always, there is a small life hack.

It is enough to install a lock washer under the nut and the risk of loosening of contacts becomes much less. In addition, it will not be superfluous to observe a few more rules:

• Make wiring with a power reserve and not overload the network.
• Select machines so that the wires do not work to the limit.
• Do not be lazy to open the junction boxes and monitor the condition of the connections.
• For bolted connections, use "black" bolts. Making an additional transition of metals "zinc-steel-zinc" is not the best solution.

As for the screw terminal blocks, I never put them on aluminum (from the word in general). In principle, I use terminal blocks only for connecting bulbs and lamps. If the wiring is aluminum, the ill-fated Vago is best suited here.

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Share your experience in the comments. I am sure it will be useful for many.