The 7/8" Connector: Industrial Power Connectivity
The 7/8" circular connector (also called "Mini 7/8" or "Mini Power") is an imperial-thread power connector with a ~22 mm coupling diameter, widely deployed across North American industrial power distribution since the 1980s. Where M12 L-coded is the modern European standard for DC power up to 16 A, the 7/8" remains the workhorse for legacy installations, North American factory builds, and AC power applications up to 12 A.
Katlax manufactures the full 7/8" portfolio at our Santej, Gandhinagar facility — 3-pin, 4-pin, and 5-pin variants in both European Color Code and American Color Code wire-colour conventions. The two conventions are mechanically identical (same connector, same mating) but use different wire-colour assignments per pin — a critical detail when sourcing replacement cables for existing installations.
European Color Code vs American Color Code
This is the most common 7/8" specification question we get. The connector hardware is the same; only the wire-colour assignment per pin differs. Choosing the wrong code on a replacement cable means rewiring on-site or risking miswired equipment.
European Color Code (4-Pin example):
| Pin | European | American |
|---|---|---|
| 1 | BN (Brown) | BK (Black) |
| 2 | WH (White) | WH (White) |
| 3 | BU (Blue) | RD (Red) |
| 4 | BK (Black) | GN/YE (Green/Yellow — PE) |
Note the European code reserves green/yellow for the protective earth on the 5-pin variant (pin 3); the American code uses green/yellow on pin 4 of the 4-pin variant for the equipment ground. Always confirm which code your installation uses before ordering replacement cables. Full wire-colour tables for 3-pin / 4-pin / 5-pin in both codes are on the Pin Assignment reference.
Pin Configurations
| Pins | Typical use case | Voltage / current |
|---|---|---|
| 3-Pin | Two-wire DC power + ground (European), AC + neutral + ground (American) | 300 V / 12 A typical |
| 4-Pin | Three-conductor power + ground | 300 V / 12 A typical |
| 5-Pin | Three-phase + neutral + protective earth | 600 V / 9 A typical |
Technical Specifications
- Thread: 7/8"–16 UN (imperial coarse thread).
- IP rating: IP67 standard when mated; IP68 available on request.
- Current rating: Up to 12 A per contact (3-pin and 4-pin); 9 A per contact (5-pin).
- Voltage rating: 300 V AC/DC (3-pin, 4-pin); 600 V (5-pin).
- Mating cycles: 100 minimum; field-tested to 500+ in industrial environments.
- Operating temperature: −40 °C to +85 °C standard.
- Housing material: Nickel-plated brass standard.
Cable Material Options
- PVC — general-purpose, cost-optimised, static installations.
- PUR (polyurethane) — oil-resistant, abrasion-resistant, suitable for drag-chain and flex applications.
- TPE — chemical-resistant and food-safe options for hygienic environments.
7/8" vs M12 L-Coded — Which to Use
A common decision in modern designs: stick with legacy 7/8" or migrate to M12 L-coded?
- Choose 7/8" when: Retrofitting or extending an existing 7/8" installation; matching North American legacy infrastructure; specifying AC power at 300 V or 600 V; requiring the higher pin-to-pin spacing for high-current contacts.
- Choose M12 L-coded when: Designing new equipment; the application is DC power up to 16 A at 63 V (IO-Link DC distribution, modern PROFINET-based machine builds); space constraints favour the smaller M12 form factor; aligning with EU industrial automation standards.
Katlax supplies both — see the M12 catalogue for L-coded variants. We also do mixed cable assemblies (7/8" on one end, M12 L-coded on the other) for transition periods during equipment retrofits.
Applications
- Factory power distribution: Motor branch circuits, valve manifold power feeds, sensor-network 24 V DC distribution.
- Conveyor systems: Motor-drum power on belt and roller conveyors — the long-standing 7/8" application in material handling.
- HVAC equipment: Fan motor connections, blower power feeds in large commercial installations.
- Lighting: High-bay industrial lighting circuits, especially in older North American factories.
- Solar string combiners: Lower-current solar array interconnects (above this, switch to M40 or specialised PV connectors).
- Refrigeration and food processing: Compressor power, fan motor feeds with TPE-jacketed washdown cables.
Why Katlax for 7/8"
Katlax manufactures 7/8" in-house alongside our M-series portfolio — vertically integrated from injection moulding through over-moulded cable assembly and 100% testing. We support both European and American color codes on the same SKU lineup, with custom assemblies for specific cable lengths, jacket materials, and pin configurations.
Certifications: CE, UL listing, ISO 9001:2015, IPC/WHMA-A-620 for wire harness manufacturing, self-declaration on RoHS and REACH. Full cert pack on the downloads page.
Lead times: standard 7/8" SKUs 2–3 weeks ex-works; custom cable assemblies 3–4 weeks; OEM private-label runs from 500 pieces.
Browse, Compare, and Quote
Use the filter sidebar above to narrow by pin count, gender, cable length, or color code convention. For mixed assemblies (7/8" to M12, 7/8" to bare wire, etc.), our wiring harness team builds custom configurations to spec. Request a quote for any non-standard requirement.