Schneider Electric R9F12125 Resi9 1P 25 A C-curve MCB

R9F12125: Resi9 1P 25 A C-curve miniature circuit breaker

The R9F12125 is a Schneider Electric Resi9 miniature circuit breaker (single-pole, 25 A, C curve) with thermal-magnetic tripping and a 6000 A breaking capacity at 230 V AC. It clips onto a DIN rail, carries ON/OFF indication on the toggle and is finished in white (RAL 9003), the colour that distinguishes the Resi9 range from the grey Easy9 range. Seven Star LLC supplies the R9F12125 in Oman and the GCC as an independent supplier based in Muscat.

Reading the reference: across the references in this lane the digit after R9F12 follows the pole count and the last two digits follow the rated current, so R9F12125 reads as 1P and 25 A. This is our reading of the pattern and the product title, not a published ordering table, so always confirm the full reference. With one protected pole it breaks the phase conductor only and is intended for a single-phase branch where the neutral runs separately. The datasheet quotes 230 V AC as the operating voltage.

Technical specifications of the R9F12125

Durability and environment for the R9F12125

The Resi9 datasheet lists 20000 cycles mechanical and 10000 cycles electrical operating cycles, which are higher than the 10000 and 4000 cycles that the Easy9 datasheets in the same lane quote. For a board that is switched often, for example circuits that are isolated at every maintenance visit, that margin is worth noting. Protection is IP20, pollution degree 2 and tropicalisation level 2.

Operating ambient is -25 to 60 °C and storage -40 to 60 °C, with humidity up to 95 % at 55 °C. In a Gulf building, enclosure temperature can be much higher than room temperature, and a breaker carrying its full rating in a closed board will run hotter than one lightly loaded, so allow for derating margin and ventilation. This unit itself is not a weatherproof device; the enclosure must keep dust and water away.

Fault level, insulation and limitation class of the R9F12125

The listed breaking capacity is 6000 A Icn at 230 V AC 50/60 Hz, with a rated operational voltage of 230 V AC. The insulation voltage Ui is 440 V AC and the impulse withstand Uimp is 4 kV, with overvoltage category III. The limitation class is 3, the highest class defined in the product standard, which means the breaker restricts the let-through energy of a fault more strongly than a class 1 or 2 device.

The datasheet does not publish a separate service breaking capacity line for this reference, so the 6000 A figure is the number to compare with the prospective short-circuit current at the board. In small residential and commercial supplies this is normally comfortable, but a board close to a large transformer or a long way upstream of a smaller one can see very different values, and the calculation belongs to the installer. Confirm that the network type and voltage on site match the 230 V AC line before ordering.

Installation and upkeep of the R9F12125

De-energise and prove dead, then clip the R9F12125 onto the rail and check that the toggle moves freely. Insert stripped conductors fully, tighten to 2 N.m with a calibrated driver, and fit ferrules where the datasheet lists flexible cable with ferrule. After switching on, confirm that the ON/OFF indication matches the toggle position and label the circuit.

Re-torque terminals during scheduled inspections, especially in boards that are warm or that carry vibration, and look for discoloured plastic that signals heat at a termination. If a breaker trips on a short circuit, find the cause before resetting; if it trips repeatedly on a normal load, the rating or the load is wrong rather than the device.

Trip behaviour of the R9F12125 at 25 A

The datasheet gives a magnetic tripping limit of 5 to 10 times In. At 25 A that corresponds to roughly 125 A to 250 A, the window in which the instantaneous element is expected to act on a short circuit. Smaller overloads are left to the thermal element, which takes longer to react the closer the current is to the rating. The C characteristic is the usual compromise for residential and light commercial wiring: it allows the short inrush of lamp drivers, small transformers and motors, yet it still reacts faster than a D curve to a real fault.

This unit is best matched to air-conditioner supplies, water heaters and larger socket groups. The conductor must be chosen first from the load, installation method and ambient temperature; the breaker is then picked to protect that conductor, not the other way round. The full time-current curve is part of the manufacturer’s published characteristics and is not reproduced here.

Selection checklist for the R9F12125

• Conductor: size the cable for the load and the installation method, then check that 25 A protects it.
• Poles: 1P suits a phase-only single-phase branch.
• Voltage: the datasheet lists 230 V AC; make sure it fits the supply.
• Fault level: compare 6000 A Icn at 230 V AC 50/60 Hz with the prospective short-circuit current.
• Load: C curve for moderate inrush; very high inrush needs a different characteristic.
• Space: 2 modules, 18 mm of rail.

Information to send with an RFQ for the R9F12125

• Exact reference R9F12125 and the quantity needed.
• Supply voltage, system type and earthing arrangement.
• Prospective short-circuit current at the board, if known.
• Load description and cable size for the circuit.
• Other poles or ratings needed in the same order.
• Delivery location and timeline.

Documents and quotation

The manufacturer datasheet for the R9F12125 is attached on this page and holds the full specification summarised above.

Send us the reference R9F12125, quantity and delivery location and Seven Star LLC will reply to your request. We supply as an independent supplier based in Muscat.