10 March,

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Electrical Cable Types, Sizes, and Installation

An electrical cable has the purpose of transporting electrical energy from one point to another. Depending on their final application, cables can have different configurations, always basing their design on national and international regulations.

Electrical cable Voltage

An electric cable is measured in volts and, depending on these, they are categorized into one group or another:

• Low voltage cables (up to 750 V): in a variety of applications, and with thermoplastic and thermoset coatings. They are designed and built according to harmonized standards.
• Low Voltage cables (up to 1,000 V):

  (also called (0,6/1 kV) The cables in this section are used for industrial power installations in various fields (general industry, public installations, infrastructures, etc.). They are designed according to international standards (UNE, IEC, BS, UL).

• Medium Voltage cables:

  from 1 kV to 36 kV. They are used to distribute electricity from electrical substations to transformer stations.

• High Voltage cables:

  from 36 kV. They are used to transport electricity from the generating plants to the electrical substations.

Types of electrical cable by their use

Low voltage cables

Flexible cables for wiring electric cabinets. These electric cables are especially suitable for domestic use, for installation in public places and for internal wiring of electrical cabinets, switch boxes and small electrical appliances.

Energy cables for industrial facilities and public places. It is common to find power cables in applications for power transmission in all types of low voltage connections, for industrial use and for variable frequency drive (VFD).

Cables with aluminium or steel reinforcement for installations with risk of mechanical aggression. It is also common to find armoured cables in places where rodents are present, as well as in installations in premises with a risk of fire and explosion (ATEX).

The use of extra flexible rubber cables is very varied. We can find rubber cables in fixed industrial installations as well as in mobile service. Welding cables should have a rubber sheath, which allows high currents to be transmitted between the welding generator and the electrode.

High Security Halogen Free (LSZH) Cables with low smoke and corrosive gas emission in case of fire are suitable for use in wiring of electrical panels and public places, installations of all kinds in public places, individual derivations, emergency circuits, public distribution networks and also for mobile service.

These cables are specially designed to transmit electrical energy in the extreme conditions that occur during a prolonged fire, guaranteeing supply to emergency equipment such as signalling, smoke extractors, acoustic alarms, water pumps, etc. Their use is recommended in emergency circuits in places with public concurrence.

Control cables for fixed or mobile installations should be extremely flexible, as they are mainly designed for small household appliances, for the interconnection of machine parts used for manufacturing, for signalling and control systems, for the connection of motors or frequency converters, for signal transmission where the voltage induced by an external electromagnetic field may affect the transmitted signal or for power supply connections to avoid generating electromagnetic fields.

These are flexible and shielded cables for the transmission of signals between equipment in industrial installations. Especially suitable for optimum data transmission in environments with a high level of electromagnetic interference.

These cables are particularly suitable for connecting photovoltaic panels, and from the panels to the DC to AC inverter. Thanks to the design of their materials and their cover, which is especially resistant to solar radiation and extreme temperatures, they can be installed outdoors with full guarantees.

There is a wide variety of electric cables for special installations such as: temporary light garland installations at trade fairs; connections for overhead cranes, hoists and lifts; applications in submerged pumps and drinking water areas such as aquariums, purification systems, drinking water fountains or in swimming pools for lighting, purification and cleaning systems.

Aluminium cables for power transmission are suitable for fixed installation indoors, outdoors and/or underground.

Medium Voltage Cables

Medium Voltage Cable type RHZ1 with XLPE insulation, halogen free and non flame and/or fire propagating. They are cables perfectly adapted for the transportation and distribution of energy in Medium Voltage networks.

Medium Voltage cable with HEPR insulation, halogen-free and not flame- and/or fire-propagating Ideal for the transportation and distribution of energy in Medium Voltage networks.

MV-90

Medium Voltage cable with XLPE insulation, according to American standard. For transportation and distribution of energy in Medium Voltage networks.

Copper and aluminium medium voltage cable for special applications. Especially recommended for installations where there is a risk of presence of oils and chemical agents of the hydrocarbon type or their derivatives.

Top Cable has a wide range of electrical wiring. Do not hesitate to consult our catalogue and find any cable you need:

Download the Top Cable catalogue here.

Components of an electrical cable

An electric cable consists of:

• Electric conductor: which channels the flow of electricity
• Insulation: it covers and contains the electric flow in the conductor.
• Auxiliary elements: that protect the cable and guarantee its longevity.
• Outer sheath: it covers all the mentioned materials protecting them from the outside.

Types of electric conductors

• Bare wire conductor: single wire in solid state, not flexible and without coating.
• Aluminum electrical conductors: in some cases, aluminum conductors are also used, despite the fact that this metal is 60% worse conductor than copper.
• Copper electrical conductors: the most commonly used material.
• Flexible copper wire conductor: it is a set of fine wires covered by an insulating material. They are flexible and malleable.
• Single-core cable: a cable with a single conductor.
• Multi-core cable: a cable that has several conductors.

Types of insulation for electric cables

The insulation consists of placing an insulating coating on the conductor to prevent current leakage. They are classified into two large groups: thermoplastic and thermoset.

1. Thermoplastic insulation

They are most common in the manufacture of electrical cables are:

• PVC:Polyvinyl chloride
• Z1: Polyolefins
• PE: Linear polyethylene
• PU: Polyurethane

2. Thermosetting insulation

The most common are:

• EPR: Ethylene Propylene
• XLPE: Crosslinked Polyethylene
• EVA: Ethyl Vinyl Acetate
• SI: Silicone
• PCP: Neoprene
• SBR: Natural Rubber

Types of metal protections for electrical cables

In some cases, the cables may have metal shields.

• Screens: these are electrical metal protections applied to isolate the signals that pass through the interior of the cable from possible external interference.
• Armours: these are mechanical protections that protect the cable from possible external aggressions: animals, blows, etc.

Nomenclature of electrical cables according to standards

Each cable has a standard designation. This designation is composed of a set of letters and numbers, each with a specific meaning. This designation refers to a series of product characteristics (materials, nominal tensions, etc.) that facilitate the selection of the most suitable cable for your needs, avoiding possible errors in the supply of one cable by another.

When a cable does not clearly indicate these data, it may be a defective cable, which does not comply with safety regulations or guarantee the cable&#;s life and proper operation.

Designation according to type of insulation

nomenclatureCable typeRCrosslinked polyethylene (XLPE)XCross-linked polyethylene (XLPE)Z1Halogen-free thermoplastic polyolefinZHalogen-free thermosetting elastomerVPolyvinyl chloride (PVC)SHalogen-free thermosetting silicone compoundDEthylene-propylene elastomer (EPR)

Screen designation, interior lining, armature seat

nomenclatureCable typeC3Copper wire screen, helically arrangedC4Copper shield in the form of a braid, on the assembled insulated conductors.VPolyvinyl chloride (PVC)Z1Halogen-free thermoplastic polyolefin

If there is no screen, no inner lining and no armature seat, no letter is used.

Designation of the different types of armor

nomenclatureCable typeFSteel strapping arranged in a helical pattern.FAAluminium strapping arranged in a helical patternFA3Longitudinally corrugated aluminium stripMSteel wire crownMAAluminium wire crown

Designation of the outer sheath

nomenclatureCable typeVPolyvinyl chloride (PVC)Z1Halogen-free thermoplastic polyolefinZHalogen-free thermosetting elastomerNVulcanized chlorinated polymer

Conductor&#;s designation

nomenclatureCable typeKFlexible copper (class 5) for fixed installationsFFlexible copper (class 5) for mobile servicesDFlexible for welding machine cables. When there are no letters on it, the conductor is made of solid copper, class 1 or 2.ALAL If the conductor is made of aluminium, (AL) is indicated.

Tensión nominal

Ratedvoltage0,6/1 kVRated voltage 1,000V

Explanation of the number of conductors

nomenclatureCable typenGSNumber and cross-section of wires, in mm2 , with Yellow/Green conductornxSNumber and cross-section of conductors, in mm2 , without conductor Yellow/Green

For more information, please visit Mingda.

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Cable design rules

The cable design rules are also referenced in the marking of each cable:

• UNE
• IEC
• UNE

Additional data

nomenclatureCable typeCECE CE marking is compulsory for the marketing of the product in the European Community. This marking can be on the product or on the packaging.Manufacture dateDate of manufacture (YYMMDD). The date of manufacture is usually placed for traceability purposes. Traceability makes it possible to know who, when and where has carried out each stage of the process and with which materials.

You can review concepts through this video that we have prepared:

Dimensioning criteria of electrical conductors

There are two sizing criteria for copper conductors:

• In the AWG-American Wire Gauge, conductors are defined by specifying a number of wires and a diameter of each wire.
• In European sizing (mm2), the conductors are defined by specifying the maximum resistance of the conductor (Ω/km). Solid or flexible conductors are defined by specifying the minimum number of wires or the maximum diameter of the wires that form it. In addition, the actual geometrical sections are somewhat smaller than those indicated as nominal.

Electrical cable measurements

CROSS-SECTION in mm2(AWG)CURRENT CONSUMPTIONUSED

25 mm2

4

Very highCentral air conditioning and industrial equipment..

16 mm2

6

High airConditioners, electric stoves and electric power connections.

10 mm2

8

Medium high

Refrigerators and dryers.

6 mm2

10

Medium

Microwave and blenders

4 mm2

12

Medium

Lighting

2.5 mm2

14

UnderLamps

1.5 mm2

16

Very low

Thermostats, bells or security systems.

Types of colours in electrical cables and their meaning

The colours of the electrical cables are governed by the International Electrical Commission Standard IEC . For the identification of the conductors, the following colors are allowed: black, brown, red, orange, yellow, green, blue, violet, gray, white, pink and turquoise.

• Neutral conductor: blue. It is recommended not to use more blue conductors to avoid confusion.
• Phase conductor: black, grey or brown.
• Protective or earthing conductor: two colours, yellow and green. The use of yellow or green single-coloured cables is only permitted in places where, for safety reasons, there is no possibility of confusion with the earthing system.

Electrical wiring is the basis of most electrical projects. For a successful renovation or remodeling job, you need to know how to identify electrical cables and determine the right kind of electrical wire for your application.

Learning the wiring basics is an essential first step for any electrical project. Although many people use the terms &#;wires&#; and &#;cables&#; interchangeably, they are slightly different. Wires are the individual conductors in a single jacket, while cables assemble two or more wires inside a jacket.

This guide will help you understand electrical wiring so you can identify wires when investigating issues and choose suitable materials for a new project.

Types of Electrical Wires

Knowing the types of electrical wire you might encounter can help you find the best wire for house wiring and other projects. Electrical wires are measured in gauges related to the wire&#;s diameter and current-carrying capacity. The higher the wire gauge, the smaller the wire. Most electrical wires are either copper or aluminum.

Other than size and material, electrical wires come in a couple of configurations:

• Stranded wire: Stranded electrical wire is a flexible woven strand of conductors, which you can easily pull through bends in the conduit &#; the tubing that protects the wire.
• Solid wire: The single, rigid conductor in solid wires is better suited for applications where you need to push them through the conduit.

Types of Electrical Cables

Individual wires can create various electrical cable combinations for many different applications when run together. Here are the four main types of electrical cables:

Romex® Nonmetallic Cables

The Romex® Nonmetallic (NM-B) cable is one of the most common brands of nonmetallic electrical cables found across indoor applications, primarily homes and small businesses. This cable typically has two or three conductors and a ground, all wrapped inside polyvinyl chloride (PVC) insulation and a jacket made of nylon. NM-B cables are available from two to 14 gauges and can withstand temperatures of 90&#;, as long as the location is dry.

The most commonly used NM-B cables include the Romex® NM-B 14/3 cables, which are ideal for indoor outlets, three-way switches and split receptacle circuits. Electricians use Romex® NM-B 12/3 cables in three-way switches and split receptacle circuits.

Underground Feeder Cables

Underground feeder (UF-B) cables travel below ground to bring power to areas like detached garages, outbuildings and outdoor lighting and pumps. Its rugged construction and PVC jacket make it ideal for outdoor applications, direct burying and indoor applications where weather damage is a concern.

UF-B cables don&#;t need a conduit when buried, although they will need one in places where the cable exits the ground. UF-B cables can withstand temperatures of up to 90&#; and come in gauges from six to 14. These cables can have two or three conductors, which can be solid or stranded.

Metal-Clad Cables

As the name suggests, metal-clad (MC) cables have a metal sheath that makes them durable in unfinished and damage-prone areas. This cable is ideal in dry and wet conditions and in residential, commercial and industrial buildings. An interlocked aluminum jacket makes MC cables great for burial with a conduit, embedding in cement or plaster and more.

MC cables come in gauges from two to 14 with anywhere from two to four conductors wrapped in nylon jackets. These sturdy wires protect against demanding conditions and temperatures up to 90&#;. Copper MC cables are made of bare, solid and stranded copper to meet a wide range of needs.

Tray Cable

Tray cable is one of the most versatile types of cable. Its construction consists of copper wire covered with a PVC jacket and thermoplastic, high-heat nylon (THHN) insulation.

Tray cable is available in gauges from two to eight and has three or four conductor options to help electricians and manufacturers complete many different projects. If you&#;re looking for a type of wire that does it all, tray cable is a great all-purpose cable.

SE-R Cable

Service entrance reinforcement (SE-R) cable is cable featuring copper wires surrounded by THHN insulation and a sturdy PVC jacket. It also has a ground wire. These materials give it UV and water resistance and flame retardance, making it good for both indoor and outdoor usage. When used outdoors, SE-R is not appropriate for direct burial, and electricians must use it in conduit.

Common uses for SE-R cable include use as an aboveground service entrance cable and for panel feeding to multi-residential buildings. It is rated for 600 volts and 90&#; in both wet and dry conditions. SE-R is available in different gauge sizes, from six to 4/0, to suit different applications. All options come in a gray jacket.

WesBell Electronics&#; SE-R cable maintains many approvals from outside organizations, including the U.S. Military, ASTM International and UL Solutions:

• Military specification A-A
• ASTM
• UL 83
• UL 854
• Registration, Evaluation, Authorization and Restriction of Chemicals (REACH)
• Restriction of Hazardous Substances (RoHS)

When comparing S-ER vs. SE-U cables, service entrance unarmored (SE-U) cables have notable differences. The first is in their shape. SE-R cable is round, while SE-U cable is flat. The second is their ground wires, or lack thereof &#; SE-R has a ground cable, while SE-U does not. Because of this, electricians don&#;t commonly use SE-U for sub-feed applications like SE-R. However, they do use it in service entrances. Additionally, SE-U cables are not stranded, making them a little more time-consuming to use.

Types of Electrical Wires We Offer

As electrical applications vary significantly, you will need to source the right type of wire for your needs. Here&#;s an overview of the electrical wires we offer at WesBell Electronics and a brief explanation of their materials and uses.

Bare Copper

Bare copper wire is a vital element in various electrical cables, from overhead communication wiring to electronics, residential wiring and telecommunications. Uninsulated, solid wire is one of the best electrical conductors and comes in various configurations and gauges from two to 26. You can also find bare copper in individual wires and electrical cables.

Copper provides high flexibility and fair corrosion resistance, making it ideal for wiring in tight indoor spaces. In addition, grounding wires consist of bare copper. Manufacturers sometimes anneal bare copper wiring to strengthen it for extensive flexing and bending. However, bare copper wires must be used indoors or in conduit, as they cannot withstand very harsh conditions.

Tinned Copper

Bare copper has good corrosion resistance, although humid and hot conditions weaken this characteristic. In these applications, tinned copper is often the solution. You can even use it in projects near seawater, as it is also saline-resistant. Tinned copper wires are also uninsulated, but they have a tin coating. This coating prevents strands from fraying and offers the conducting benefits of copper wiring with some additional protection from deterioration.

Adding tin to a copper wire significantly improves its corrosion resistance in wet and humid environments while retaining its ability to conduct electricity. Tinned copper can withstand moisture and higher temperatures. Tinned copper wire is available in gauges two to 26, allowing electricians to use these wires in difficult-to-reach places and ground electrical systems.

TFFN

Electrical wire insulation comes in several materials to suit different applications. Some stranded copper electrical wires use thermoplastic flexible fixture nylon (TFFN), which consists of PVC insulation with a jacket made of nylon. TFFN wires have a bare copper conductor, but their insulation makes them suitable for outdoor, indoor and in-conduit applications.

The TFFN coating makes these wires resistant to water, heat, gas, moisture and oil. This makes TFFN wire suitable for a broader range of applications than bare copper wires. TFFN wire is resilient to temperatures in dry environments up ten to 90&#;. TFFN wires are limited because they only come in 16- and 18-gauges.

THHN

THHN is another type of electrical wire insulation. These wires consist of a solid or stranded copper conductor, thermoplastic insulation like PVC and a nylon coating. The insulation provides excellent protection in high heat for the copper conductor within.

THHN wires are among the most common insulated wires because they meet most building codes. With excellent resistance to water, gas, chemicals, oils and heat of up to 90&#;, these wires are ideal across various applications. THHN wire has a wide gauge range &#; sizes larger than one are measured in thousands of circular mils.

USE-2 Sola

Underground service entrance (USE-2) is a single-conductor electrical wire, which electricians commonly use underground. This wire provides wide-reaching power distribution capabilities with a temperature rating as high as 90°C and a voltage rating of 600 volts. These wires are ideal for several different applications, but the most common use is for photovoltaic power.

XHHW

Another copper wire type is cross-linked polyethylene, high-heat-resistant and water-resistant, or XHHW-2. This kind of insulation allows copper wire to serve in a wide range of general-purpose applications, granting it more durability and flexibility as well as several other beneficial characteristics.

How to Identify Electrical Cables

With so many different types of electrical cables, it can be challenging to cut through the confusion and ensure your wiring project is safe. These tips will help you identify electrical cables to determine what you&#;re looking at and what you need.

1. Decode the Colors

Manufacturers use color-coding on cables and individual wires to quickly tell electricians the cable&#;s or wire&#;s characteristics. Understanding a cable&#;s color helps you maintain consistent wiring and protect your project&#;s safety. The color of a cable&#;s outer sheath tells you information like the circuit&#;s amperage rating, which is the strength of its electrical current and the wire&#;s gauge.

However, using a color code for electrical cable sheaths is still optional and relatively new. If your project has electrical cables from before , their colors may not comply with current color codes. This overview of standard electrical cable colors will give you the basic knowledge to determine a cable&#;s characteristics:

• Black: Cables with a black sheath have either six- or eight-gauge wire and deliver 40 to 60 amps. This includes cables like the Romex® NM-B 8/3.
• Orange: Orange-sheathed cables have 10-gauge wire and can handle 30-amp circuits. For instance, Romex® NM-B 10/3 cables have orange sheaths.
• Yellow: NM-B cables with a yellow sheath, like Romex® NM-B 12/2 cables, are rated for circuits with 20 amps. Yellow-sheathed cables are 12-gauge.
• White: White-sheathed NM-B cables, like Romex® NM-B 14/2 cables, are rated for 15 amps. Cables with white sheaths have 14-gauge wires.
• Gray: Gray cable sheaths are associated with UF-B cables, like the UF-B cable 14/2. This cable delivers 15 amps.

Individual wires within a cable are also color-coded. These colors signal the wire&#;s specified or preferred use:

• Red or black: These colors indicate that a wire is current-carrying or &#;hot.&#;
• White: White wires are usually neutral conductors, returning power to the service panel.
• Bare or green: Wires that are bare copper or green are grounded. You may also see grounded wires that are green with yellow stripes.

2. Know Your Labels

Labels on electrical cables consist of letters and numbers that help you determine a cable&#;s use at a glance. The information on your electrical wire markings includes the following:

• Numbers: One electrical cable classification combines two numbers with a hyphen between, like 12-3. The first number in this sequence denotes the conductor&#;s gauge, while the second refers to the number of conductors inside the cable.
• Letters: The labels on the outside of an electrical cable indicate the maximum voltage rating, the wire material and whether a ground wire is present. NM-B cables include labels like &#;G&#; or &#;w/G&#; for ground wires and &#;CU&#; for copper wires. UF-B cables may be labeled with their acronym plus &#;Sunlight Resistant.&#; Individual wires also have labels for their material &#; for example, THHN or TFFN.

What to Know Before Working on Electrical Cables

Before beginning any electrical project, it&#;s crucial to learn how to understand electrical wiring and how to use it. Doing so ensures you complete your project successfully and safely. Here are six key reminders to consider before working with electrical cables in your next project:

1. Install Wires and Cables With Your Application in Mind

Your application determines the kind of electrical wiring you use. For example, Romex® NM-B cables are great for indoor use. However, they aren&#;t the most rugged wires you can find, making them unsafe for outside use. You will need to take additional precautions for outdoor projects or switch to a more durable cable, like MC cables.

Before picking wire for your project, ask yourself these questions to determine the suitable material:

• Is this project indoors or outdoors?
• Is there high moisture, heat or humidity present?
• Will the electrical wiring need to fit tight spaces?
• Would using a conduit protect this wire or cable from deterioration?

2. Match Wire Gauges With Existing Wiring

A wire&#;s gauge is specific to the amount of amperage the circuit uses. You&#;ll need to use electrical wire that can handle the current that is already flowing through the building. In residential projects, you&#;ll most commonly find 12- and 14-gauge wires. Larger gauges like six, eight and 10 are best with large appliances, electric water heaters and central air units.

If you&#;re adding an outlet or a switch, ensure you know the existing wire&#;s size before starting. It&#;s essential to use wire with the same gauge as existing wiring within a circuit, as this prevents short-circuiting and fires. Check the labels on the existing wire to determine its gauge.

3. Protect Cables in Outdoor Applications

Standard electrical cables have thinner insulation, making them better suited for indoor projects where walls and floors protect them. When installing wiring for an outdoor job, it&#;s vital to use a cable that can withstand corrosion, moisture, humidity and other damage.

Outdoor electrical cables use hearty insulation to protect the wiring. Direct-burial cables can be buried with or without a conduit and remain secure from deterioration. You can also use cables that are not rated for direct burial, although they require a conduit like a thick casing of PVC.

4. Select the Right Conduit Type

When you need to protect your electrical cables or wires, fitting them inside a conduit is an excellent option. Conduits offer all electrical cables and wires additional protection against moisture, corrosion and damage.

There are different conduit types to suit all applications. Metal conduits are not commonly used today, as flexible plastic conduits are more useful in tight areas. It&#;s also essential to select the correct size conduit. When running individual wires through a conduit, you must stay below the fill capacity, which depends on the wire gauge, conduit size and material.

5. Strip Wires Carefully

Stripping electrical wire is the process of removing the PVC coating without nicking or damaging the conductors underneath. Wire stripping is one step in creating connections in all kinds of electrical projects. If done incorrectly, the connection could be interrupted or a short circuit could occur.

For the fastest and most accurate wire stripping, use a wire stripping tool. These wire strippers are for specific types of wire, so be sure to use the right kind.

6. Always Check Local Building Codes

It&#;s essential to check local building codes before starting any electrical project, as you may need to obtain special permits. The National Electrical Code (NEC) regulates the types of electrical cables and wires used in specific applications. These regulations often vary between states. Check with your local code enforcement department so you have the guidance you need.

It&#;s also a good idea to have your local building code inspector examine your installation once it&#;s complete to ensure you&#;ve followed safety regulations.

Choose WesBell Electronics for Your Electrical Cable and Wire Needs

At WesBell Electronics, we sell high-quality electrical wires and cables to suit various projects across residential, commercial and industrial applications. Our cost-effective and long-lasting materials will help you get the best results from your electrical project.

Our expert technicians can help you determine the correct wire or cable for your job. We also offer wire processing services to take care of the wire cutting, stripping and preparation for you. Get in touch with us today to learn more about our services.

For more BS Standard Cable information, please contact us. We will provide professional answers.