What Is a Closed-End Connector? Types and Selection Criteria
A closed-end connector is a connection cap with an insulating body closed at one end, into which stripped conductor ends are inserted together and crimped.
A closed-end connector (cable end cap, CE-type terminal) is a connection cap with an insulating body closed at one end, into which stripped conductor ends are inserted together from the same side and crimped with pliers. The metal sleeve inside joins the conductors, and the plastic body outside insulates the joint. It joins two or more conductors without a terminal block in luminaire, appliance and motor lead wiring, or caps a spare conductor end.
Although its Turkish product name contains the word for ferrule, it is not a cable ferrule: a ferrule gathers the strands of a single conductor and goes into a terminal, while a closed-end connector joins conductors inside itself and caps the end.
Types
- Size (CE number): Numbers such as CE-1, CE-2, CE-3, CE-5 and CE-8 indicate the body size; the higher the number, the larger the total conductor cross-section the part accepts. The cross-section range for the same number varies between manufacturers.
- Body material: The models in the catalogue have a nylon 6.6 body. Heat-shrink and gel-filled waterproof types also exist on the market; they are not in the catalogue.
- Inner sleeve: In the catalogue models the sleeve is tin-plated copper; the plating protects the copper against oxidation.
Selection criteria
- Total cross-section: Add up the cross-sections of the conductors to be joined (e.g. 3 × 1.5 mm² = 4.5 mm²) and confirm on the product page that the result lies within the range of the size you choose. Below it the crimp will not hold; above it the conductors will not fit.
- Number of conductors: For the same total cross-section, many thin conductors are harder to seat than a few thick ones. Strip the ends to the same length and insert them together.
- Temperature: According to the product data, the body withstands up to 105 °C and its flammability rating is UL 94 V-2. Inside a luminaire, keep it away from spots where the lamp or driver exceeds this.
- Pliers: Use an insulated-terminal crimping tool with a die suitable for closed-end connectors; the die must match the size of the part. Options are in the connector and terminal crimping pliers category.
Common mistakes
- Stripping too long: Bare copper is left outside the body and the insulation is defeated. Match the strip length to the sleeve length.
- Squeezing with combination pliers or cutters: The sleeve is not crimped evenly; the conductor later pulls out and the joint heats up.
- Using one size for every joint: Too much cross-section cuts strands, too little leaves a loose joint.
- Putting tensile load on the joint: A closed-end connector is not a mechanical splice; secure the cables so the joint is not under strain.
- Using it in damp locations: A standard nylon body is not waterproof.
Products in the catalogue
The End Closure Parts category lists 5 active products from KSN (October 2026):
| Size | Stock code | Box quantity |
|---|---|---|
| CE-1 | `KSN2416` | 1000 pcs |
| CE-2 | `KSN2417` | 1000 pcs |
| CE-3 | `KSN2415` | 1000 pcs |
| CE-5 | `KSN2418` | 1000 pcs |
| CE-8 | `KSN2419` | 500 pcs |
All have a tin-plated copper sleeve and a nylon 6.6 body. Confirm the cross-section range of each size on the product page. For terminal, screw or busbar connections, insulated cable terminals are a separate group.
Frequently asked questions
How many wires fit into a closed-end connector?
The total cross-section decides, not the number of wires. If the sum of the conductor cross-sections is within the size's range and the ends fit into the sleeve together, the joint can be made.
Which pliers are used to crimp a closed-end connector?
An insulated-terminal crimper with a die for closed-end connectors. Combination pliers crimp unevenly and can tear the body.
What is the difference between a closed-end connector and a cable ferrule?
A ferrule goes on a single conductor end and into a terminal. A closed-end connector joins several conductors inside itself and, being closed, does not go into a terminal.
Can the end of a single unused wire be capped with a closed-end connector?
Yes, a single conductor can be crimped to insulate a spare wire end. Its cross-section must be within the range of the chosen size; otherwise the crimp will not hold.