Wann reicht 0,75 mm² bei einem Netzkabel aus?

Bei kurzen Leitungen und Standard-Anwendungen kann 0,75 mm² ausreichend sein. Entscheidend sind aber immer Produktkennzeichnung, Zulassung, Stecker, Kupplung, Nennstrom und die vorgesehene Anwendung.

Wann ist 1,5 mm² die bessere Wahl?

1,5 mm² ist häufig sinnvoll bei längeren Leitungen, Dauerbetrieb, anspruchsvollen IT- oder Industrie-Umgebungen sowie überall dort, wo mehr Reserve bei Spannungsfall und Erwärmung gewünscht ist.

Erhöht 1,5 mm² automatisch den zulässigen Strom?

Nein. Der größere Querschnitt reduziert vor allem Widerstand, Spannungsfall und Erwärmung. Der zulässige Strom hängt weiterhin von Stecker, Kupplung, Kabeltyp, Zulassung und Kennzeichnung ab.

Warum ist der Querschnitt bei längeren Leitungen wichtiger?

Mit zunehmender Länge steigt der Widerstand der Leitung. Ein größerer Querschnitt hilft, Spannungsfall und Wärmeentwicklung zu reduzieren.

Main page » Mains lead and the cross-sectional area

Mains connection cable and the cross-section: a crucial detail

Selecting the correct power cable cross-section: 0.75 mm², 1.0 mm² or 1.5 mm²

The conductor cross-section affects resistance, voltage drop and heat generation. For short, standard applications, a smaller cross-section may be sufficient. For longer cables, continuous loads, or IT, industrial or measurement environments, 1.5 mm² is often the more robust and reliable choice.

B2B selection guide: Lower voltage drop; greater reserve under continuous load. Note: The data sheet remains authoritative

MAG Netzkabel mit 1,5 mm² Leiterquerschnitt

Consider the length

The longer the cable, the greater the impact of resistance and voltage drop.

Consider continuous load

Long operating times or high loads often call for a larger cross-sectional area.

Note the rated current

The cross-sectional area does not automatically increase the permissible current of the plug or connector.

Practical pre-selection based on cable length

The following table provides a quick guide to typical 10A mains connection cables in everyday B2B use. It does not replace checking the specific product labelling, the data sheet and the operating conditions.

up to 2.0 m	0.75 mm² may be sufficient for standard applications.
Over 2.0 m up to under 5.0 m	1.0 mm² is often the more balanced choice.
From 5.0 m	1.5 mm² is usually the more robust option.

Important: Permissibility, rated current and scope of application always depend on the specific cable type, the approval, the marking, the connectors and the application. A larger cross-section primarily means lower losses and greater reserve capacity, but does not automatically result in a higher permissible current.

When is 1.5 mm² particularly suitable?

Continuous operation: lower heat build-up in the cable under the same load.
Longer cables: lower voltage drop due to lower conductor resistance.
IT, industry, measurement environments: greater headroom for more demanding set-ups.
Unclear conditions: 1.5 mm² is often the safer choice.

Technical basics explained briefly

Resistance: a smaller cross-section means higher resistance per metre.
Voltage drop: under load, the voltage across the cable drops.
Heating: Power loss is converted into heat.
Margin: a larger cross-sectional area reduces resistance, voltage drop and heat generation.

Guideline values for copper conductors at 20 °C

0.75 mm²	approx. 24.5 Ω/km as a guideline for calculation
1.0 mm²	approx. 18.1 Ω/km as a guideline for calculations
1.5 mm²	approx. 12.1 Ω/km as a guideline for calculation

These values are for illustrative purposes only. Values specified in standards and data sheets may vary depending on conductor class, construction, temperature and product. The specific product specifications always take precedence for technical approval.

Calculation example: 10 A with a cable length of 5 m

For the sake of simplicity, both the forward and return conductors are taken into account; for a cable length of 5 m, this corresponds to a conductor path of approx. 10 m. The values illustrate the order of magnitude of the difference between the cross-sections.

Cross-sectional area	Voltage drop at 10 A	Power loss in the cable	Classification
0.75 mm²	approx. 2.45 V	approx. 24.5 W	Possible for short standard applications; less reserve at 5 m under load
1.0 mm²	approx. 1.81 V	approx. 18.1 W	A balanced compromise for medium lengths
1.5 mm²	approx. 1.21 V	approx. 12.1 W	significantly more headroom for longer cables and continuous loads

Rule of thumb: Voltage drop ≈ current × resistance × cable length. Values may vary depending on alternating current, temperature, contact points, cable type and actual application.

Selection guide: Which power cable cross-section is suitable?

This selection guide is deliberately practical: it specifies when a standard cross-section is usually sufficient and when 1.5 mm² is advisable as a more robust solution.

MAG power cables with 1.5 mm² for greater headroom

When reserve capacity matters, 1.5 mm² is often the more robust choice: lower conductor resistance, less voltage drop and reduced heat build-up. This is particularly beneficial for longer cables, continuous loads, IT environments, industrial workstations and professional setups.

Typical benefits in B2B applications

Greater headroom for demanding applications.
Lower losses with longer cables.
Reduced heat build-up during prolonged operation.
Faster pre-selection via Q150 in the shop.

View the Q150 range – custom-made products

MAG Netzkabel 1,5 mm² – überdurchschnittlicher Querschnitt

FAQ on power cable cross-sections

When is 0.75 mm² sufficient for a power cable?

For short cables and standard applications, 0.75 mm² may be sufficient. However, the product marking, approval, plug/connector, rated current and intended application are always decisive factors.

When is 1.5 mm² the better choice?

1.5 mm² is often advisable for longer cables, continuous operation, demanding IT or industrial environments, and wherever greater margin is required to account for voltage drop and heat build-up.

Does 1.5 mm² automatically increase the permissible current?

No. The larger cross-section primarily reduces resistance, voltage drop and heat build-up. The permissible current continues to depend on the plug, connector, cable type, approval and marking.

Why is the cross-section more important for longer cables?

As the length increases, the resistance of the cable increases. A larger cross-section helps to reduce voltage drop and heat generation.

What information is helpful when making a product recommendation?

Important factors include cable length, plug type/coupler, rated current, operating environment, continuous load (yes/no), target market and existing equipment requirements. If in doubt, a brief technical pre-selection is advisable.

Note: This page is intended as a technical guide for procurement, IT, industry and project planning. It is not a substitute for electrical design, product testing or an assessment of the specific application. The technical data and approvals for the respective product are authoritative.

Back