Schneider Electric A9N18346 C120N 2P 100 A B-Curve MCB

A9N18346: C120N 2P 100 A B-curve Acti9 circuit breaker

The A9N18346 is a Schneider Electric Acti9 C120 miniature circuit-breaker in the C120N performance class: two-pole, 100 A, with B curve. It is a thermal-magnetic device on a 35 mm DIN rail, 54 mm wide, and the datasheet marks it suitable for isolation. Seven Star LLC supplies the A9N18346 in Oman and the GCC as an independent supplier based in Muscat.

Reading the reference from the product title: C120N names the breaking-capacity version (standard within the C120 family), 2P the number of protected poles, 100 A the rated current at 30 °C and B the trip curve. The C120 is the large-frame member of the Acti9 modular range, used where a 63 A to 125 A feeder is needed in a modular panel rather than a moulded-case device. A9N18346 follows that pattern.

Technical specifications of the A9N18346

Installation, torque and routine checks

Strip 15 mm of insulation, fit the conductor into the tunnel terminal and tighten to 3.5 N.m; under-torqued terminals on a 100 A circuit are a common source of hot spots. The handle can be sealed in either position to deter tampering, but the datasheet does not list a padlock accessory for this reference, so use a panel-door lock where lockout is required. Clip the unit onto the 35 mm rail and fit it so the ON/OFF indication is visible.

After energising, run a thermographic scan under load during the first season, then include the breaker in the yearly panel inspection: re-torque, clean dust, and operate the handle to keep the mechanism free. Electrical endurance is listed as 5000 cycles, so a 100 A device on a frequently switched circuit may reach this sooner than a feeder that rarely operates.

Related C120 references to compare with the A9N18346

These neighbouring references appear in the same Schneider Electric range; the table compares the points that most often change a selection.

Moving between the N and H class changes breaking capacity, and moving between pole counts changes width and DC voltage capability; rating and curve only change the thermal and magnetic settings.

Breaking capacity of the A9N18346 on AC and DC

The C120N version quotes the following breaking values in the datasheet. Icn is the household-and-similar capacity (EN/IEC 60898-1) and Icu the ultimate capacity (EN/IEC 60947-2).

The N version gives 20 kA at 220–240 V AC and 10 kA at 380–415 V AC for the multi-pole types listed here, adequate for most building and utility distribution but not for boards next to a large transformer. On DC, two poles are quoted at up to 250 V DC; for a higher DC voltage confirm the pole wiring arrangement against the manufacturer’s DC diagrams, and a polarity check should be part of commissioning.

Frame size and pole layout of the A9N18346

A two-pole C120 occupies 6 modules of 9 mm, which is 54 mm of rail and 0.41 kg of mass. Neutral position is listed as left. The earth-leakage option is a separate add-on block, and the breaker is compatible with comb busbars and distribution blocks. Two poles suit single-phase feeders with a switched neutral, or DC circuits where both polarities must be interrupted.

Because a C120 is deeper and wider than the small iC60 range, count the busbar and enclosure space early. Dimensions of 81 × 54 × 73 mm are listed, which fits standard modular enclosures with a 35 mm rail.

Selection checklist and RFQ details for the A9N18346

Use these points before you confirm the part number.

• Pole count: 2P must match phases, neutral and any DC polarity to be interrupted.
• Rating and curve: 100 A, B curve, with enclosure derating applied.
• Fault level at the board against the Icu table above (C120N class).
• Space: 54 mm of rail, and whether an add-on block (shunt trip, auxiliary, earth-leakage) must be fitted alongside.
• Conductor: the terminals accept 1–50 mm² rigid or 1.5–35 mm² flexible.
• Discrimination with upstream and downstream devices, using the manufacturer’s tables.

When you send the enquiry, include:

• Part number A9N18346 and required quantity.
• Board fault level and supply voltage, AC or DC.
• Required add-on blocks, such as shunt trip or earth-leakage.
• Delivery location and required date.
• The project specification if a certificate or test report is requested.

Trip curve and rating logic

The thermal element protects the cable against sustained overload; the magnetic element releases on short circuit. For A9N18346 the datasheet gives 3–5 × In as the magnetic tripping limit with a B characteristic. A B-curve release in this size is uncommon, so confirm that your upstream device and fault-level study actually call for it, rather than the C curve used for most distribution feeders.

The 100 A figure is defined at 30 °C. Panels in Oman often run well above that, so apply the manufacturer’s derating tables for the real enclosure temperature and for adjacent hot devices; a 100 A rating sits mid-range in the C120 family and is common for sub-main feeders to a distribution board.

Where the A9N18346 is used in Oman and the GCC

Typical homes for a two-pole 100 A B-curve device are main and sub-main feeders in commercial buildings, workshop and utility boards, pump-house and desalination distribution panels, and camp or accommodation supplies in oil and gas. The listed operating range of -25–70 °C and 95 % humidity at 55 °C cover the heat and condensation of the Gulf coast, but ventilation of the enclosure and sand-proof gland plates remain the installer’s job. For DC auxiliary and battery circuits the C120N 2P breaker can also be applied within the voltage limit stated above.

Documents and quotation

The manufacturer’s product datasheet for the A9N18346 is attached on this page for reference; it is the document to use when you verify ratings, dimensions and approvals against your own design. It lists the rated values for this exact reference.

To receive a quotation, send the part number A9N18346 with quantity and delivery location in Oman or the GCC. Seven Star LLC replies with availability and lead time as an independent supplier based in Muscat.