Notes on 12v Electrical cable sizes

HIGH PERFORMANCE Single Core – Multi Strand wiring cable for use in most electrical applications including:

• Automotive Marine Motors and many others requiring superior PERFORMANCE.
• Good resistance to temperature, petrol, diesel, lubricating oils and diluted acids.

Cables can be terminated with

• Red Terminal Crimps (0.5mm² - 1.5mm² 20 – 16 AWG)
• Blue Terminal Crimps (1.5mm² - 2.5mm² 16 – 14 AWG))
• Yellow terminal Crimps (4.0mm² - 6.0mm² 12 – 10 AWG)

Do not confuse this cable with automotive thin wall cable, this also cable has high impact resistant standard size insulation. It’s standard size insulation is 0.5mm thicker than thinwall cable. Our cables are NOT copper coated aluminium or unbranded imports, we do not sell  non-certified cables.

• Application – Automotive / Marine / Appliance / General
• Standard Hi-Performance PVC Insulation
• Compatible Voltage – 6v 12v 24v 48v 60v
• Conductor Material Copper Class 5 BS EN 60228:2005
• Insulation – Good Resistance to: Petrol, Diesel, Oils and Diluted AcidsÂ

CSA Cross Sectional Area (mm²)	Amps Max Continuous	Power Rating at 12 v Watts	No. of Strands / Strand Size mm²	American Wire Guage (Approx)	Outside Diameter Ø Inc Insulation (Approx)	Approx Wire Diameter Ø Exl Insulation (Approx)	Insulation Radial Thickness	Weight Grammes per Metre	Stock Colours Available
1.0mm²	14A	168 W	32/0.2mm²	18 AWG	3.0mm	1.40mm	0.8mm	17 g/m	Rd Bk Bl Br Gn GY Gr Or Pi Vi Wh Ye
1.5mm²	21A	252 W	30/0.25mm²	16 AWG	3.3mm	1.70mm	0.8mm	20 g/m
2.5mm²	30A	360 W	50/0.25mm²	14 AWG	3.8mm	2.00mm	0.8mm	30 g/m
4.0mm²	41A	492 W	56/0.3mm²	12 AWG	4.4mm	2.80mm	0.8mm	49 g/m	Rd Bk Bl Br GY Gr Ye
6.0mm²	53A	636 W	84/0.3mm²	10 AWG	4.9mm	3.30mm	0.8mm	70 g/m	Rd Bk Bl Br GY Gr
10.0mm²	75A	900 W	80/0.4mm²	8 AWG	6.5mm	4.30mm	1.10mm	125 g/m

Colour Key Rd -Â Red, Bk – Black, Bl – Blue, Br – Brown, Gn – Green, GY – Green/Yellow, Gr – Grey, Or – Orange, Pi – Pink, Vi – Violet, Wh – White, Ye – Yellow

Cable Considerations

Measuring Cable

Electricity is measured in terms of amperage, voltage, and wattage. Amperage (amps for short) is a measure of the AMOUNT of electricity used. Voltage (volts) measures the pressure, or FORCE, of electricity. The amps multiplied by the volts gives you the wattage (watts), a measure of the WORK that electricity does per second.

Think of it this way: Electricity flowing through a wire is like water flowing through a garden hose. The amount of water that can fit through the hose depends on the diameter of the hose (amps). The pressure of the water depends on how far open the tap is (volts). The amount of work that can be done (watts) depends on both the amount and the pressure of the water (volts x amps = watts).

Use the online Ohm’s Law Calculator at www.ohmslawcalculator.com to caluculate your power requirements.

Terminology

Cable Size or “Gauge”

In Europe cable is measured CSA or Cross Sectional Area in Millimetres Squared. AWG or American Wire Gauge is still used as a comparison

This is not the diameter but the area of the cross section (i.e looking directly at  a cut section of the conductor circle (if round) and measured in mm2. The measurement is of the copper only.

The insulation is not a part of the calculation of CSA or Cable gauge.

Cores and Conductor

The core of the cable or conductor can be made of a solid, standard or finely stranded wires. This is called the core or conductor.

Cable or Core sizes are measured by the total CSA of conductor or strands.

The most commonly seen cable sizes are usually seen by

• Number of cores
• Number of strands per core
• CSA of the individual strand

Eg. A Single Core 2.5mm 50/0.25 cable would equate to a single core or conductor containing 50 strands of wire, each strand measuring 0.25mm squared. The total CSA or area is 2.5mm squared. This size cable is equivalent to a 14 AWG American Wire Gauge Cable.

Insulation

The “jacket” of the cable or individual cores is an important factor when determining your application. Insulation can widely differ; some may look the same but contain different materials than will affect the performance and conductivity.

It is best to search for your application keyword i.e automotive, appliance etc and then look for the cable specifics to confirm it meets your requirements. ISO or British Standards also reinforce the cable specification. Some standards refer to the conductor and others to the insulation. Insulation can come in a variety of colours and quality.

Most importantly the insulation specification is directly relevant to the capacity and performance.

The same conductor size may well carry different currents because of the insulation properties associated with the cable.

A good example is Automotive Thin Wall Cable. The very name refers to the insulation being thin. In the 1990’s the automotive industry incorporated this type of cable into modern vehicle wiring looms. The insulation is a high grade hard PVC. Most cables only have a 0.3mm insulation thickness and together with a tough hard PVC insulation. This makes them hard wearing and they can easily be bundled together and the thinness makes them both lighter in weight and thinner in volume. Standard automotive cable is still widely used in aftermarket fitments and the rewiring of older looms. This is generally 0.8mm in thickness.

DERATING YOUR CABLE

Derating is the operation of a device at less than its rated maximum capability in order to prolong its life. Typical examples include operation below the maximum power rating, current rating, or voltage rating. When electricity is passed through a cable, heat is produced. The insulation absorbs the heat. Maximum continuous power of a cable in a specification refers to in being at sea level in free ambient air.

When you cover, bundle or duct a cable you must de-rate it. If you plan to use the cable at the upper end of the maximum continuous power this is a very important consideration to make. The cables will get hot and melt if you do not. This includes running a group of cables together at the upper end of the maximum power rating. The derating factor is a complex calculation and depends on the individual application and the material that come into contact with the cable.