Selecting the correct electrical terminal for each wire gauge is essential to ensure safety, performance, and durability in electrical installations. An incorrect selection can lead to poor contact, excessive heating, energy loss, and even serious system failures. With this in mind, CRIMPER has prepared this guide to explain, in a simple and straightforward way, how to identify the ideal wire gauge and choose the most suitable terminal for each application.
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What is wire gauge and why does it matter?
Wire gauge represents the cross-sectional area of the conductor, usually measured in square millimeters (mm²). It defines the amount of current the cable can safely carry. The larger the gauge, the greater the electrical conduction capacity.
In crimping, the wire gauge must always match the terminal specification. When this does not happen:
- The terminal may not properly secure the cable;
- Contact resistance increases;
- The connection point may overheat;
- There is a risk of rupture, sparking, or complete failure.
How to identify the correct wire gauge
Read the cable marking: Most conductors have the gauge printed on the insulation.
Use proper measuring tools: When there is no marking, a caliper or a wire stripping tool with a scale can help identify the conductor diameter.
Consult technical tables: Residential, industrial, or photovoltaic installations may require specific gauges depending on circuit current. Every CRIMPER product includes technical tables to help you select the best gauge for your application.
Types of terminals and their applications by wire gauge
CRIMPER offers several terminal lines for different needs. Here is how to choose correctly:
1. Pre-insulated terminals (rings, pins, ferrules)
Recommended for residential and commercial installations.
Common gauges: 0.5 mm² to 6 mm².
Ideal use: electrical panels, light automation, and quick, secure connections.
2. Non-insulated terminals
Used in control panels, technical assemblies, and professional applications.
Common gauges: 1.5 mm² to 120 mm².
More robust and temperature resistant.
3. Tubular terminals (ferrules)
Very common in solar energy systems and automation.
Common gauges: 0.5 mm² to 10 mm².
They ensure excellent contact area and firm crimping.
4. Compression terminals (for large cables)
Used in infrastructure and power applications.
Gauges: 25 mm² up to 500 mm², depending on the model.
Require hydraulic crimping tools or high-pressure tools.
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Consequences of choosing the wrong terminal
Choosing a terminal incompatible with the cable gauge is a mistake that compromises the entire installation. The most common risks include:
- Loose or poorly formed crimping;
- Increased electrical resistance;
- Energy losses;
- verheating at the connection;
- Risk of fire or system interruption;
- Frequent maintenance and intermittent failures.
CRIMPER tips to always get the gauge right
- Strictly follow the gauge indicated on the terminal.
- Use the appropriate crimping tools for each type of terminal.
- Avoid improvisation: never use larger or smaller terminals “to adjust later.”
- In critical systems (industry, photovoltaic, automation), prioritize tin-plated copper terminals.
- After crimping, perform a visual inspection and, if possible, a pull test.