When copper is heated in a flame, it loses its characteristic reddish brown colour. This is due to a chemical reaction between the copper and the oxygen in the air. Copper and oxygen combine to form a new compound called copper oxide which is black in colour.

Reaction of copper with air Copper metal is stable in air under normal conditions. At read heat, copper metal and oxygen react to form Cu2O.

(a) When copper metal is heated in air, it gets oxidised to form copper oxide.

Copper is another metal that can form many oxides. The one formed when copper is heated and reacts with oxygen is copper (II) oxide, also known as cupric oxide. When copper is placed in a flame with oxygen, the flame changes colour to a bright green. The copper (II) oxide that results is black and insoluble in water.

For example, copper produces a blue flame, lithium and strontium a red flame, calcium an orange flame, sodium a yellow flame, and barium a green flame. This picture illustrates the distinctive colors produced by burning particular elements.

Over time copper will naturally change colors – transforming from a shiny brown color to darker browns, then blues and finally greens after a number of years. When exposed to the natural elements such as wind and rain, copper develops this “patina” which actually protects and preserves the metal underneath.

Why Copper Tarnishes Copper is a reactive metal. In a process called oxidation, copper reacts slowly in the presence of oxygen, resulting in copper oxide. This is what we call tarnish, which is generally perceived as a brown or black coloration on the surface.

Copper wire can turn black due to a process call oxidization. When the copper comes into contact with oxygen, the reactions slowly cause the wire to form a black and sometimes green coating. Copper wires will turn black when in contact with moisture.

Clean or polish copper ;to the desired sheen, clean off any residue and apply ProtectaClear or Everbrite to protect the copper from tarnish and corrosion. Copper with patina can be protected from fading and tarnish.

Removing Corrosion. Add 1 tablespoon (17.06 g) salt and 1 cup (236.58 ml) vinegar to a bowl. Salt and vinegar can help clean off any tarnish or corrosion that remains on your copper wire. Mix the solution together until the salt is well incorporated with the vinegar.

Copper wire is used for electrical connections between the breaker box and the electrical outlets and switches in your home. A bad copper wire is a fire hazard and requires immediate replacement.

They Can Corrode Over time, copper is seriously in danger of corrosion. There’s no way to avoid it, and while you can care heavily for your cables, eventually the copper will no longer be able to hold up to the damage. Fortunately, a fiber optic cable will never corrode, thus costing you far less in the long run.

Most homes and electrical appliances rely on copper wire to transfer electricity for two reasons: it is a very good conductor, and is easy to mold and bend. Copper is not difficult to come by (though its abundance is not as great as that of some other conductive metal), so the price is reasonable for residential use.

Electrical wiring in homes has traditionally been copper since the introduction of electricity in homes in the late 19th century. Aluminum wiring was introduced to homes in North America in the mid-1960s.

Although most copper wiring can last up to 100 years, it’s the wiring insulation that can deteriorate. After about 25 years, house wiring insulation can become cracked and damaged, which can lead to exposed wire.

Copper is commonly used for building wire because of its conductivity, strength, and reliability. Over the life of a building wire system, copper can also be the most economical conductor. Copper used in building wire has a conductivity rating of 100% IACS or better.

What does aluminum wiring look like? You can tell if you have aluminum wire in your home by checking your electrical panel or looking at cables running through the basement or attic. The cables may be marked AL, ALUM or ALUMINUM, indicating aluminum wire.

This solution is just what it sounds like: a complete replacement of the aluminum wiring in the house with traditional copper wiring. Depending on the home’s size, age and ease of access to old wiring, you should plan to spend $10,000 or more for this repair.

The wiring itself isn’t a problem; aluminum conducts electricity safely. The trouble is at the connections. The U.S. Consumer Product Safety Commission (CPSC) reports that homes with aluminum wiring are 55 times more likely to have “fire hazard conditions” than homes wired with copper.

The most common type of wiring in modern homes is in the form of nonmetallic (NM) cable, which consists of two or more individual wires wrapped inside a protective plastic sheathing. NM cable usually contains one or more “hot” (current-carrying) wires, a neutral wire, and a ground wire.

Yes you can mix 12 and 14 gauge wire with a 15 amp breaker on the circuit. But it is not recommended because the next homeowner or electrician may be confused and put a 20 amp breaker on it again.

Three types of wire used are :

• live wire ( Red colour)
• neutral wire(Black colour)
• earth wire (Green colour)

The designation 12/2 indicates AWG 12 wire with two conductors (AC hot and AC neutral), 12/3 indicates AWG 12 wire with three conductors (two AC hot and AC neutral). Both designations also typically include a smaller bare copper earth ground conductor. AWG 12/2 is used for a single breaker 120V 20A max circuits.

12-2-2 NM-B Wire (4 total conductors plus ground) – Sold by the foot. Color Code: Black, white, red, white with red stripe. Applications: Non-metallic sheathed NM-B cable is used in normally dry installations in residential wiring, as branch circuits for outlets, lighting and other residential loads.

ROMEX® 12/3 wire is used in buildings for circuits that use higher amperage than the standard 20 amps. Most people are not familiar with this type of wire because it is used to hook up heavy-draw appliances such as water heaters and central air conditioning.

Perhaps you mean 12/2 wire to be used with 220 Volts power supply.so,yes you can. size of conducting wire is independent of the voltage with which it has to be used. Higher the voltage, more is the thickness of the insulation.

Intentionally overload one 12-2 cable If you look in the code book, 12 AWG wire is legal to 30 amps if you can run it at 90 degrees C.

Yes, you can convert 110v to 220v. In most cases, the existing circuity of a site needs to be upgraded by an electrician to do so. But, when you use a 110v to 220v step-up converter, you can install it DIY.

If you have 2 220 outlets and each one is 20 amps. You’ll need to use #8 wire for the whole circuit including a 40 amp breaker.