Schneider Electric A9R21240 Acti9 iID 2P 40 A 30 mA RCCB

A9R21240: Acti9 iID 2P 40 A 30 mA type A RCCB

The A9R21240 is a Schneider Electric Acti9 iID residual current circuit breaker (RCCB) with 2 poles, a rated current of 40 A, a sensitivity of 30 mA and an earth-leakage protection class of type A. It clips onto a 35 mm DIN rail, is 36 mm wide (4 modules of 9 mm) and works from 230–240 V AC at 50/60 Hz. Seven Star LLC supplies the A9R21240 in Oman and the GCC as an independent supplier based in Muscat.

Reading the reference: across the A9R references in this lane the digit after A9R follows the type (2 for type A), the next digit follows the sensitivity, then the pole count and the rating code. That gives A9R212 followed by the rating code for 40 A. This is our reading of the pattern and the product titles, not a published ordering table, so confirm the full reference before ordering.

Durability, ratings and environment of the A9R21240

The datasheet lists 20000 mechanical and 15000 electrical operating cycles, an insulation voltage Ui of 500 V AC, a 6 kV impulse withstand and pollution degree 3. Protection is IP20 on the device and IP40 when it sits in a modular enclosure. It operates from -25 to 60 °C and may be stored from -40 to 85 °C.

The wider operating range, from -25 °C, is helpful in boards that see large swings in temperature, such as unconditioned outdoor kiosks. Inside a closed board in a hot Oman summer the internal temperature can pass the room temperature by a wide margin, so give this unit ventilation and spacing from heat sources such as large contactors and busbars.

Technical specifications of the A9R21240

Where the A9R21240 sits among iID RCCBs

The table compares nearby iID references. Pole count sets the width and voltage, type sets the residual waveform handled, and sensitivity sets the tripping threshold.

Choosing 30 mA for the A9R21240

The A9R21240 has a 30 mA threshold, the figure used for supplementary protection of people against direct contact on socket and final circuits. The datasheet gives an instantaneous tripping time, so the device acts without an intentional delay. If it is installed upstream of other residual current devices, remember that it can trip together with them, and discrimination has to be arranged with a selective device or by splitting the circuits.

Leakage current accumulates across all the equipment downstream, and filters in drives, computers and cleaners all leak a little to earth. If many such loads share one RCCB, the sum may approach the tripping threshold and cause nuisance trips, which is why a board is often split into several residual current stages instead of one large one. Check the earthing system and the installation rules that apply on your site before settling on a sensitivity.

Typical uses of the A9R21240 in Oman and the GCC

In the region this unit is typically specified for workshops and small factories, site offices and labour camps and mosques, schools and clinics, always together with a miniature circuit breaker or fuse ahead of it. Heat, dust and coastal humidity are the main ageing factors, and they favour closed, well-sealed enclosures and regular test-button checks. For process plants and critical loads the choice of residual current protection and its sensitivity is normally set by the project specification, so follow that over any general advice.

Selection checklist for the A9R21240

• Supply: 230–240 V AC and 2 poles, to match a single-phase circuit.
• Current: the load through the device must not exceed 40 A, and the upstream protection must not exceed the same value.
• Sensitivity: 30 mA against the protection goal, people, equipment or fire.
• Waveform: type A against the loads on the circuit.
• Backup: a short-circuit device upstream, since the iID does not trip on overcurrent.
• Space: 4 modules, 36 mm of rail.

How the A9R21240 protects: residual current without overcurrent

An RCCB compares the current going out on the live conductors with the current coming back. If the difference reaches its sensitivity, which for this unit is 30 mA, a trip mechanism opens all 2 poles. The datasheet lists voltage-independent tripping, meaning the device does not need the line voltage to operate, so it still trips on a residual current if the supply dips or a neutral is lost upstream.

Type A detects the sinusoidal residual current that type AC handles and also pulsating DC residual current, which is what a fault in single-phase rectifier circuits, dimmers and many electronic drives can produce. It is the common choice where equipment with power electronics sits on the circuit.

The iID has no thermal or magnetic element. It will not open on an overload or a short circuit, and the listed 10 kA conditional short-circuit rating assumes a short-circuit protective device ahead of it. Pair this unit with a miniature circuit breaker or fuse of no more than its own 40 A rating, and check the backup protection against the upstream arrangement.

Information to send with an RFQ for the A9R21240

• Exact reference A9R21240 and the quantity needed.
• Supply voltage, system type and earthing arrangement.
• Load description, including drives or electronic equipment on the circuit.
• Upstream protective device and its rating.
• Other poles, ratings or sensitivities needed in the same order.
• Delivery location and timeline.

Documents and quotation

The Schneider Electric datasheet for the A9R21240 is attached on this page and holds the full specification summarised above. It is dated 8 Nov 2026 as printed on the manufacturer’s document.

Send us the reference A9R21240, quantity and delivery location and Seven Star LLC will reply to your request. We supply as an independent supplier based in Muscat and do not act for the manufacturer.