2.5 mm Electrical Cable Amp Rating (Explained With Examples) | PortablePowerGuides (2024)

Cable size is very important. It has to match the needs of your device. If the electrical requirements of the device are too high, the cable will overheat. If this issue goes unchecked, you may start a fire. Therefore, before you install 2.5mm wire in your residential or commercial setting, you must first determine whether or not it is suitable for the application you have in mind.

How Many Amps Can A 2.5mm Cable Carry?

2.5mm2 can accommodate anywhere between 16 and 45 amps depending on the location and temperature. Take factors such as the length and voltage drop into account because they can change the cable’s carrying capacity.

2.5mm Wire Amp With Respect To Temperature

TemperatureAmp Rating

With Respect To Single And Three Phase Electricity

Single Phase (2 cables)24A
3 Phase (3-4 Cables)21A

But you cannot use that range to determine the suitability of 2.5mm2 cable for your application. It is simply too broad.

Unless you have a low-capacity application in mind (for instance, if you want to wire the lighting in a house), don’t install conductors of this size without first consulting a professional.

Tell an electrician what you want to do, and they will determine whether or not this wire size is acceptable.

Contractors use these cables for indoor domestic purposes. That includes wiring sockets.

As you can see, the temperature matters because 2.5mm cable could handle 20 amps in free air. But you are more likely to encounter an average rating of 16 amps in a residential setting.

Let’s look at the 2.5mm cable amps in different situations.

Wire enclosed in an insulated wall20A
Enclosed in conduit23A
Thermal insulation in contact with the ceiling < 100mm21A
Thermal insulation in contact with the ceiling > 100mm17A
Thermal Insulation cable touching the wall21A
Thermal Insulation cable not touching the wall13.5A

Related post:

  • How Many Amps Can 6mm Cable Carry? (With Examples)
  • 8 Gauge Wire Amps
  • 50 Amp Wire Size Chart
  • 30 Amp Breaker Wire Size

How To Find Correct Amps For 2.5mm Cable?

You can use a clamp meter to measure the current.

But that will only tell you the volume of the current it is transmitting, not the maximum amount of current it can handle.

Fortunately, you don’t have to perform any calculations or measurements to find the amperage of a 2.5mm2 cable.

Most people use tables. They are quite easy to find. They will show you the size of the wire in AWG and mm2. If you follow each row, it will also show you the corresponding amperage of each wire size.

This is the easiest way to determine the number of amps the cable can carry.

It is also worth noting that 2.5mm is the cross-sectional area of the cable in millimeters. While many electricians prefer this unit of measurement because of its accuracy, you don’t have to use it.

You can rely on the gauge. It is much easier to interpret.

According to cable joints, a 2.5mm2 cable is 14AWG.

It isn’t the thickest. But it is wide enough to carry a substantial quantity of current.

Why Amp Rating Matters?

The amperage is a measurement of a wire’s current carrying capacity. To be more specific, the amperage tells you the amount of electricity the conductor can carry without melting.

The amperage matters because electricity generates heat whenever it passes through a wire. This is because conductors have a resistance that opposes the flow of current.

If you know the amperage, you can ensure that a cable doesn’t carry more current than it can handle.

To determine the carrying capacity of a conductor, you have to take into account the conductor’s size, ambient temperature, and the number of individual conductors.

  • The conductor size is obvious. The larger the size of the conductor, the more current it can carry. The ambient temperature is also equally apparent because it affects the heat generated.
  • The conductor number may confuse newcomers because they don’t realize that cables consist of multiple conductors that have been bundled together.

Things To Consider Before Using 2.5mm Wire

Finding the correct wire size for a particular application requires a lot of time and effort, especially for newcomers. You have to account for the following:

1). Type

According to smart gauge, you have to match the wire type to the voltage. They have used the example of applying a 1000V cable to a 24V system, which is perfectly fine. But the opposite (applying a 24V line to a 1000V system) is dangerous.

2). Durability

The strength and durability of the cable should match the type of application.

For instance, mobile devices use tiny wires (0.1mm2). You cannot use them in a setting that exposes the conductors to extreme stress because the cables won’t survive.

You must also consider additional threats such as chemicals and heat that can destroy the wire. The right cables can defend against corrosive components such as chemicals.

3). Medium

Do you expect to run the wire through a specific medium?

The medium changes the carrying capacity of the conductor. For instance, 2.5mm2 cable can withstand 30 amps, but that is primarily true for free air. If you want to run the wire through a conduit, it can safely withstand 20 amps.

The medium affects the amount of heat the current will generate as it runs through the conductor. Because a 2.5mm2 wire in conduit doesn’t have the same ventilation as a wire in free air, you have to use a smaller load. Otherwise, it may overheat.

If you have all these factors in mind, you can identify the best application for a 2.5mm2 cable. Because it isn’t necessarily the thickest of wires, newcomers might be tempted to apply this cable size to lighting circuits.

But you don’t need wire this thick for lighting applications in a domestic setting because1mm and even 1.5mm (twin and earth) cables are perfectly adequate.

You can get by with 1mm. But if you have more lights than usual, and the cable has to cover a relatively long distance, 1.5mm is the better option. It can compensate for the voltage drop.

The best fit for 2.5mm cables is sockets. It can work as a hot, neutral, or live wire. 2.5mm cable can work with lighting circuits.

In the eyes of some homeowners, sockets do not differ that drastically from lighting circuits. But you have to remember that the wiring behind a socket doesn’t accommodate that socket. The wiring behind a socket has to accommodate the appliance you will plug into that socket.

Therefore, you need larger cables to contend with the demands of those devices and appliances.

How Many Watts Can 2.5mm Cable Handle?

2.5mm2 cable can withstand 4800 watts of power.

Cable SizeAmpsVoltWatt

You can perform these calculations yourself. You get the wattage by taking the current in amps and multiplying it by the voltage.

If your cable can take 16 amps and you have a 120V system, multiply 16 by 120. This gives you 1,920 watts. If you have a 240V system, multiplying 16 by 240V gives you 3,840 watts. Therefore, if you know the voltage and current, you can figure out the wattage on your own.

This approach is only problematic if you don’t know the amperage. This is why you have to consult an electrician. They can do a more accurate job of determining the amperage and its related wattage.

2.5mm Armored Cable Amp Rating

It can handle 36 amps. Though, like ordinary cabling, you have to consider factors like temperature and the medium.

Steel wire Armored cable has a protective layer that defends against damage. It is stronger and more reliable. People use it in harsh settings that would typically ruin ordinary cables. It is not suitable for flexible applications.

2.5 mm Electrical Cable Amp Rating (Explained With Examples) | PortablePowerGuides (2024)


How many amps can a 2.5 mm cable take? ›

2.5mm Twin And Earth Current Carrying Capacity
2.5mm20 Amps18
Jan 7, 2022

How much current can 2.5 sqmm cable carry? ›

Product Specification
Wire Size2.5 sqmm
Current Carrying Capacity14 A
Insulation MaterialPVC
3 more rows
May 7, 2019

How do you calculate the ampere rating of a cable? ›

Use the formula: P(KVA) = VA/1000 where P(KVA) is power in KVA, V is voltage and A is current in amperes. For example, if V is 120 volts and A is 10 amperes, P(KVA) = VA/1000 = (120)(10)/1000 = 1.2 KVA. Calculate power rating in KVA when you know voltage and output resistance.

How do you calculate the current carrying capacity of a cable? ›

I = KA/L. Here, I stands for the maximum current load in amperes (amps), K is a constant that depends on the type of material used in the cable, A stands for the cross-sectional area of the cable in square millimeters (mm2), and L stands for length in meters (m).

What is 2.5 mm electrical cable used for? ›

2.5mm is commonly used for behind sockets, while 1-1.5mm is most often used for lights (depending on how many lights you have in a circuit).

What gauge wire is 2.5 mm? ›

A Simple Guide on Cable AWG to Metric Conversions
Metric MM2 (Diameter)AWGApprox Strading
2.5mm14 awg50/0.25
4mm12 awg56/0.3
6mm10 awg84/0.3
10mm8 awg80/0.4
7 more rows

How many amps can mm cable take? ›

This cable is mainly used for domestic lighting circuits rated at 6 AMP.

What is the current rating of 2.5 mm 4 core cable? ›

This type of 2.5mm 4 core cable is particularly well suited to low voltage wiring and low current signal applications. The 4 Core SWA cable has a current rating of 31 Amps.

What size cable do I need for 32 amps? ›

Cable sizes: We recommend using 6mm for 32A 3 phase use, larger cables when lengths over 50m are required.

What is thumb rule in electrical? ›

Thumb Rules. Cable Capacity. For Cu Wire Current Capacity (Up to 30 Sq.mm) = 6X Size of Wire in Sq.mm. Ex. For 2.5 Sq.mm = 6×2.5 = 15 Amp, For 1 Sq.mm = 6×1 = 6 Amp, For 1.5 Sq.mm = 6×1.5 = 9 Amp.

What rating is 50 amp cable? ›

50 AMP Wire Size

For a maximum of 50 amps, you'll need a wire gauge of 6.

What cable rating for 100 amp? ›

Typical sizes of wires for 100 Amp Service are 4 AWG or 2 AWG for copper wiring and 2 AWG, 1 AWG, or 1/0 AWG for aluminum or copper-clad wiring. These sizes are also used for direct burial. When choosing 100 amp service wire size, remember that a 100 amp circuit at 240V can proceed up to 24,000W of electricity.

What is the current rating of 2.5 mm twin and earth? ›

Twin And Earth & Flat Cable Technical Specifications
1.5mm14.5 Amps20 Amps
2.5mm20 Amps27 Amps
4mm26 Amps37 Amps
6mm32 Amps47 Amps
3 more rows
Jan 7, 2022

How the maximum amount of power a cable can carry depends on? ›

The capacity of a cable to 'carry' electricity depends on the cross-sectional area of the conductors - the copper cores which conduct electricity. Cross-sectional area is measured in mm². Cable which is thicker - has a larger diameter core - can 'carry' more electricity.

Can 2.5 mm cable take 32 amps? ›

Can a 2.5 cable take 32 amps? It depends upon the type of wire, the voltage, the operating temperature, and the run length… But yes, most likely it can, however 2.5 mm is only RATED to 27 amps.

How do I know if my cable is 2.5 mm? ›

Ways to Identify Electrical Cable Sizes
  • Look at Cable Insulators. Text or numbers are printed on each cable to denote their size. ...
  • Incise the Wire. Use a wire cutter and make a cut that is perpendicular to the run of the wire. ...
  • Measure the Diameter. The diameter of the cross section must be measured in inches.
Jul 21, 2022

How many strands are in 2.5 mm wire? ›

Primarily used as a secondary switching unit supply cable, this multi-purpose cable offers high performance. This cable is also suitable for direct burial.

How thick is 2.5 mm cable? ›

The size 2.5mm refers to the cross-sectional diameter of the cores so the overall diameter is 10.7mm.

How many mm is 10 amp cable? ›

Choosing the correct size cable
Conductor SizeCurrentMaximum power (Watts)
1.0 mm210 ampsUp to 2400 Watts
1.25 mm213 ampsUp to 3120 Watts
1.5 mm215 ampsUp to 3600 Watts
2.5 mm220 ampsUp to 4800 Watts
1 more row

How many mm is 10 amp wire? ›

Current Rating: 10 Amp Color: Available In-Yellow,Blue Polycab Electrical Wire, Wire Size: 1.5 Sq Mm.

What mm is 30 amp cable? ›

2.5mm cable on 30amp mcb.

What size cable do I need for 30 amps? ›

If you are wiring an outdoor or heavy-duty outlet, you must use a 10-gauge wire with a 30 amp breaker. This is a thicker wire gauge than 12 gauge and can handle higher voltage without the risk of overheating or causing an overload.

What gauge cable do I need for 30 amps? ›

“Twelve-gauge wire is good for 20 amps, 10-gauge wire is good for 30 amps, 8-gauge is good for 40 amps, and 6-gauge is good for 55 amps,” and “The circuit breaker or fuse is always sized to protect the conductor [wire].”

Is 4mm cable OK for 32 amp? ›

The table below shows the current carrying capacity of 4mm twin and earth cable. This cable is mainly used for Radial socket circuits rated at 32 AMP, also used for immersion heaters and some cookers.

What is the 80% rule in electrical? ›

The math for the 80% rule is pretty simple. For example, if a circuit is rated for a maximum of 30 amps, it shouldn't carry more than 24 amps (80% of its capacity) to charge an EV. This rule also applies to other amperage levels such as safe charging at 40 amps on a 50 amp rated circuit.

What is the 85% rule in electrical? ›

You design a system so that the maximum amount of power you use is no more than 85% of the power ratings for every component. What does this mean? Well it means that all the components should be rated above 47.06 amps. Fifty amps is the closest nominal unit.

What is the corkscrew rule? ›

According to Maxwell's corkscrew rule: Imagine driving a corkscrew in the direction of current, then the direction in which we turn its handle is the direction of the magnetic field. This rule is used to determine the direction of magnetic field around a straight current carrying conductor.

Can 2.5 cable take 25 amps? ›

A 2.5mm cable is capable of supplying around 23-25 amps depending on the method of installation, so is fine, safe and compliant on a 20amp circuit breaker.

What size wire do I need for 40 amps? ›

The recommended size wire for a 40 amp breaker is 8 AWG.

This is the American Wire Gauge, and it is the standard that is used in the United States for determining wire size. 8 gauge wire is rated for 40 amps, and it can safely handle up to 50 amps. This 40 amp wire size can safely handle most needs.

What size wire for 50 amps at 100 feet? ›

50 Amps requires at least 6 AWG wire. Also, if you're running 50 Amps to a sub-panel 100 feet away, the appropriate wire size is 4 AWG copper.

What size wire for 90 amps? ›

Ampacities of Insulated Conductors
Wire Size75°C (167°F)
17 more rows

What cable can hold 80 amps? ›

4 AWG copper wire is used for 80 amp service.

Does amps matter in a cable? ›

The current is measured in “amperes” or “amps.” If an electrical circuit does not have the proper wire amp rating, the wire can overheat, causing irreversible damage to the conductors and wire insulation. In severe cases, overheating can even lead to fires, explosions, and serious injury.

How many volts can 2.5 mm cable take? ›

how many watts can a 2.5 mm cable take? 2.5 square BV wire, overhead wiring at 20 degrees, 220 volt power supply can be up to 4.4KW. Therefore, a 2.5 square BV wire can be used with a maximum of 4.4 KW.

Can I use 2.5 mm cable for AC? ›

So you will need 2.5 mm wire for a 1.5-ton AC. It will help the AC to work more efficiently and provide more lifespan to both AC and electrical wiring.

How do you calculate cable size and current rating? ›

To calculate the Cable Sizing one needs to divide the voltage running through the cable by the target current. For instance, If your wire has a voltage current of 150 Volts and your target is 30 then you divide 150/30. This gives you your target resistance of 5 which is required.

What size cable for 63 amps? ›

230v Single Phase 63A Extension Lead

Cable sizes we recommend using 10mm cables for lower power & shorter cables. 16mm for full 63A continuous use and longer cables.

What size cable for 20 amp AC? ›

A 20-amp circuit, protected by a 20-amp breaker or fuse, must be served by 12-gauge or 10-gauge wire.

What is 2.5 mm single core cable used for? ›

Description. The 2.5mm single core copper cable is mostly used in homes, factories and in various institutions for sockets neutral line for powering appliances that use relatively high energy for their operation.

What is 2.5 mm cable for? ›

what is 2.5mm cable used for. 2.5mm2 is suitable for power devices, household appliances, instruments and telecommunications wire. PVC insulated wire and household wire are the most commonly used type of wire. It has the characteristics of acid and alkali resistance, oil resistance, and moisture-proof.

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