Terminal Connections and Connector Selection for LED Drivers

Every LED driver terminates in a connection, and connections are the most failure-prone point in the entire lighting system. A loose screw terminal, an undersized connector, a corroded contact, or a wire inserted with stray strands can cause voltage drop, overheating, arcing, and eventually fire. Yet connection quality is rarely specified in lighting designs. In practice, the choice of connection method and connector type has a direct impact on reliability, installation speed, and long-term maintenance cost.

The most common method is the screw terminal. The wire is stripped, inserted under a screw head or into a cage, and clamped by tightening the screw. Screw terminals are simple, robust, and field-serviceable, but they have known failure modes: undertightening leaves the wire loose (high resistance, overheating), overtightening can crush or sever strands, and thermal cycling can relax screw tension over time. For constant voltage drivers, the input (mains) and output (24V SELV) terminals must be clearly separated and marked, and the terminal design must meet the creepage and clearance requirements of IEC 61347-1. The PV100's datasheet shows 0.75-2.5mm² for input and 0.5-2.5mm² for output, covering the common wiring range for a 100W driver.

Spring-loaded terminals — cage clamps or push-in terminals — have become the standard in European and Australian installations. The wire is inserted into a spring cage that clamps it with controlled, constant force, eliminating the two biggest screw terminal problems: undertightening and thermal relaxation. Push-in versions accept a stripped wire directly; lever versions open the cage for insertion. Spring terminals are faster to terminate, require no tools for push-in versions, and provide a gas-tight connection that resists corrosion. The main disadvantages are slightly higher cost and lower tolerance for repeated insertion cycles.

Insulation displacement connectors (IDCs) are common in pre-wired LED strip systems, where a flat cable is pressed into a connector that slices through the insulation to contact the conductor. IDCs are fast and reliable when used as intended, but they are generally not field-serviceable and are sensitive to conductor size and insulation thickness. They belong in factory-made harnesses rather than field connections.

For outdoor and damp-location drivers, sealed connectors are the norm: circular IP67 connectors, cable glands combined with terminal blocks, or pre-molded connectors with integrated gaskets. The critical point is that the driver's IP rating is only as good as the connection's. An IP67 driver with an unprotected screw terminal is not IP67 — moisture protection must extend through the connection. Many IP67 drivers come with pre-attached cables terminated in an IP-rated junction box or matched sealed connector pair.

Connector selection criteria go beyond terminal type. Current rating: the connector must carry the full load current with margin — for a 4.16A output, a 6A or 10A connector is appropriate. Wire range: it must accept the wire sizes used (0.5-2.5mm² covers most 24V systems). Voltage rating: SELV outputs need only low-voltage rating, but mains inputs must be rated for 230V with proper clearance. Temperature: connectors must be rated for the operating environment. Certifications: UL 486A/486B for wire connectors, IEC 60998 for connecting devices.

Installation practice matters as much as connector choice. Strip the wire to the correct length — too little and the conductor may not reach the clamp, too much and bare copper is exposed. Insert fully so no insulation is trapped. Give the wire a gentle tug to confirm it is held. For stranded wire, use ferrules where the terminal design benefits. Route wires so mechanical strain is not transmitted to the terminal, using cable ties or strain relief. And never daisy-chain two wires in a single terminal unless the manufacturer allows it — the contact area halves and the connection becomes a heat source. Ten seconds of care at each connection is the cheapest reliability improvement in the lighting industry.