LC 2pc Connector

What the LC two-piece connector is

The LC two-piece connector is the original LC design: a ferrule assembly and an outer housing as two separate parts. It meets TIA, IEC and JIS standards, is graded C under IEC 61753-1 for random mating, and it is the economical choice in the LC connector and adapter range. Radix can supply it loose or built into patch cords and assemblies to your drawing.

The LC format was created as a small form factor connector with a 1.25 mm ferrule, half the area of the SC. The two-piece design is the one most people picture when they say LC. A premium unibody version came later with a single moulded body and tighter ferrule control. The two-piece remains in wide use because it is cheap, widely compatible and good enough for a great many links.

If you are choosing between formats, the LC connector guide and the fibre connector types guide give the overview. The whole the manufacturer catalogue starts from the connector section.

Standards and what Grade C means

The two-piece LC conforms to TIA, IEC and JIS connector standards. That matters because the interface geometry has to be the same for connectors from different makers to mate. Compliance with the standards means a LC will go into a third-party adapter, and a third-party LC will go into a the manufacturer adapter.

Grade C under IEC 61753-1 refers to performance classes for connectors with random mating, meaning connectors picked at random from production and mated together. It is a standard performance class, not the best one available. The tighter grades are for connectors measured against a reference or built with tighter tolerances.

Read the insertion loss vs return loss guide for how these performance numbers are measured and why a pass on loss does not prove a pass on return loss.

Key figures

From the manufacturer’s LC family figures, the standard LC has a typical insertion loss of 0.12 dB and a maximum of 0.30 dB. Return loss is at least 55 dB for UPC, 65 dB for APC and 25 dB for multimode. The operating temperature is -40 to +75 C, and the change after 500 matings is under 0.2 dB.

The maximum is the number to budget with when a link must pass without a retest. A typical figure describes the average connector; a maximum describes the worst you should accept from a standard-grade part.

Where the two-piece LC is a good choice

• Short links. Patch cords inside a rack or between adjacent racks, where one or two mated pairs sit in a channel with plenty of margin.
• Cost-led volume. Large cord orders where a few hundredths of a dB do not decide the outcome.
• Replacement and spares. Fitting into existing LC adapters and equipment without worry.
• Multimode links. Where return loss of 25 dB or better is the norm and loss budgets are looser.
• Enterprise networks. Office riser and horizontal links with two or three connectors.

For single-mode links with four or more mated pairs, or for high-speed paths with a tight budget, look at the LC premium unibody connector. The fibre loss budget guide shows how to decide.

Two-piece against its LC siblings

All of these share the LC interface, so they mate with the same adapters. The differences are in the body, the ferrule control, the cable format and any special feature. Choosing among them is about the link requirement, not about compatibility.

Worked example: a rack-to-rack cord order

Assumed scenario, all values assumed: a hosting room needs 200 single-mode duplex LC patch cords, 2 m each, between switches and patch panels. Each channel will have two mated pairs. The designer allows 0.5 dB for connectors.

Standard LC maximum: 0.30 dB per pair, so two pairs give 0.60 dB. That exceeds the 0.5 dB allowance, so the designer cannot budget on maxima with standard parts. Using typical values (0.12 dB per pair), two pairs give 0.24 dB, which passes.

The decision depends on how the acceptance test is written. If acceptance is the measured total on each channel, standard parts will usually pass, since measured loss tracks typical. If the budget is a guarantee against maxima, premium is the safer purchase. Connector count for the order: 200 cords x 4 connectors = 800 connectors, plus spares of perhaps 2 to 5 percent as a planning figure of your own choosing.

Handling and cleaning

Use dust caps on every unmated connector, inspect before mating and clean dry, following the end-face cleaning and inspection guide. The two-piece LC is as sensitive to dirt as any other 1.25 mm ferrule connector, and a cheap connector with a clean end face outperforms an expensive one with a dirty one.

Do not hang heavy bundles from LC latches. Support cords with managers and Velcro ties rather than letting the latch bear the weight, and avoid sharp bends right behind the boot.

What to send Radix to quote it

Send details via the request a quote page, email, phone or WhatsApp. Radix is in Pune, and works to drawings, sourcing the connectors.

• Quantity of connectors, or the number of cords with lengths.
• Fibre type: OS2 single-mode, or OM3 or OM4 multimode, with core size.
• Polish: UPC or APC.
• Boot colour, and duplex clip if wanted.
• Cable outside diameter, jacket type and whether LSZH is required.
• Assembly length and tolerance.
• Opposite-end connector if different from LC.
• Test data format, if needed.

Radix tests each cord before dispatch. Common cord forms are on the LC to LC patch cord page, the OM3 LC duplex page and the OS2 LC APC page.

Buyer checklist

• Have you written the loss budget with maxima and compared with 0.30 dB per pair?
• Is UPC or APC right for the link?
• Are cords sized with enough slack for the cable manager?
• Is LSZH or another jacket required by site rules?
• Do you need a test report, and in what form?
• Have you ordered a cleaning kit with the cords?

When this is not the right part

Do not choose the standard two-piece for links with a tight loss budget, for high-speed single-mode with many connector pairs, or for panels patched very often. It also lacks the special features of siblings, such as keying, a switchable polarity uniboot or tight-packed cable support.

For sealed or outdoor links look at the IP harsh environment connectors. For other cord formats, see the fibre optic patch cords section.