Choosing Cable Plugs

The key to choosing a cable plug is matching it to the intended application while ensuring safe connections. It’s crucial to pay close attention to the plug’s type, current and voltage specifications, protection rating, and interface compatibility—avoiding improper selections that could lead to poor contact or safety hazards.

1. Clearly identify the plug type (for suitable scenarios)

Different scenarios require plugs with different structures—this is the primary prerequisite for selection.

Classified by usage environment

Standard household plugs—such as two-prong flat plugs and three-prong flat plugs (with grounding)—are suitable for home outlets and small appliances. They feature a simple design but offer a low level of protection (typically IP20).

Industrial plugs are typically three-phase four-wire or five-wire connectors (e.g., 16A, 32A), featuring impact-resistant and corrosion-proof housings with high protection ratings (IP44 and above). They are ideal for factory equipment and outdoor distribution boxes.

Waterproof plug: The housing features a sealing gasket, offering a protection rating of ≥IP67. Ideal for use in damp or wet environments such as bathrooms, outdoor lighting fixtures, and underwater equipment.

Classified by interface type

Plug - Socket Type: Detachable, allowing easy plugging and unplugging, such as household power plugs or industrial aviation connectors.

Fixed plug: Must be crimped onto the cable before use and cannot be detached—such as terminal plugs inside equipment.

II. Matching Electrical Parameters (Safety Core)

The electrical parameters of the plug must perfectly match those of the cable and equipment to prevent overload or burnout.

Rated Current: The plug's rated current must be equal to or greater than the maximum operating current of both the cable and the equipment. For example, a 10A cable should be paired with a 10A plug, while 20A industrial equipment requires an industrial plug rated at 20A or higher.

Rated Voltage: The plug's rated voltage must be ≥ the system's operating voltage. For household 220V devices, choose a 250V plug; for industrial 380V equipment, select a 440V industrial plug—this prevents excessive voltage from causing insulation breakdown.

Polarity: Choose based on whether the device requires grounding. Devices with metal casings (such as washing machines and refrigerators) must use three-prong (three-pole) plugs to ensure safe grounding; small devices without grounding requirements (like mobile phone chargers) can opt for two-prong (two-pole) plugs.

3. Pay attention to the protection rating (suitable for the environment)

The protection rating (IP code) determines the plug's resistance to dust and moisture, and should be selected based on the intended environment.

IP20: Protects only against finger contact, with no waterproof capability, suitable for dry indoor environments (such as bedroom or office outlets).

IP44: Protects against solid objects (such as dust) and splashing water, making it suitable for kitchens, balconies, or industrial areas with minor water splashes.

IP67: Fully dustproof and capable of short-term immersion (up to 1 meter deep for 30 minutes), making it suitable for outdoor use, bathrooms, and pool equipment.

IP68: Completely dustproof and capable of long-term immersion, making it ideal for underwater devices (such as dive lights and underwater sensors).

4. Ensure interface compatibility (reliable connection)

The plug must perfectly match the socket and cable connector to prevent poor contact.

The plug must match the socket: The shape and spacing of the plug's pins must align with those of the socket. For example, a household three-pin plug should be used with a national-standard three-pin socket, while industrial aviation plugs require matching sockets of the same model (such as the GX16 or GX20 series).

The plug must match the cable: The plug’s wire gauge range should include the cable’s cross-sectional area. For instance, a plug designed for 1.5–2.5 mm² cables cannot be used with thicker 4 mm² cables, as this may result in an insecure crimp connection that easily overheats.

V. Preferred Materials and Craftsmanship (Key to Durability)

High-quality materials and craftsmanship can extend the lifespan of plugs and reduce the risk of malfunctions.

Shell Material: Prioritize flame-retardant ABS and PC plastics, which are heat-resistant, impact-resistant, and less likely to ignite when exposed to fire. Avoid using inferior plastics, as they tend to age and crack over time with prolonged use.

Plug pin material: Choose pure copper or nickel-plated copper pins for excellent conductivity and oxidation resistance, which helps minimize contact resistance. Avoid iron-plated copper pins, as they are prone to rusting, leading to poor electrical contact.

Wiring technique: Prioritize plugs equipped with screw-pressed or cold-pressed terminals for secure connections; avoid choosing plugs secured solely by plastic clips, as they tend to loosen over time with prolonged use.