Schneider Electric A9C20842 iCT 40 A 2NO 220-240 V Contactor

A9C20842: two-pole 40 A contactor with 36 mm body

The A9C20842 is a Schneider Electric Acti9 contactor listed in the datasheet as: contactor iCT – 2 poles – 2 NO – 40 A – 220..240 V AC. The A9C20842 is a two-pole contactor in the 40 A frame: two normally open poles, a 220 to 240 V AC coil and a four-pitch body. It is the choice for single-phase loads that exceed the 25 A frame, such as a larger water heater or a group of lighting circuits behind one switching device. Seven Star LLC supplies the A9C20842 in Oman and the GCC as an independent supplier based in Muscat.

The coding gives the A9C family, the 40 A size, two poles with two normally open contacts (2P, 2 NO) and a 220 to 240 V AC 50 Hz coil. The datasheet lists 40 A AC-7A and 15 A AC-7B, a 250 V AC operational voltage, and a clearance of 85 mm in height (against 81 mm for the 25 A frame).

Technical specifications of the A9C20842

Power circuit and coil data of the A9C20842

The rated operational current is 40 A AC-7A; 15 A AC-7B. Rated operational voltage: 250 V AC 50 Hz. Maximum power figure: 1.6 W at 250 V AC. Coil voltage: 220 to 240 V AC 50 Hz. Hold-in consumption: 4.6 VA. Inrush consumption: 34 VA. Rated insulation voltage: 500 V AC 50/60 Hz. Rated impulse withstand voltage: 4 kV. Mechanical durability: 1000000 cycles.

Power wiring on this frame uses a higher tightening torque than the 25 A references: the datasheet lists 3.5 N.m for the power circuit and 0.8 N.m for the control circuit. The coil figures are 4.6 VA hold-in and 34 VA inrush, matching the other 36 mm frame (A9C20834), which makes it easy to share control wiring and fuses across the two.

AC-7A and AC-7B ratings of the A9C20842: reading the load categories

Two numbers describe this contactor’s capability, one per load category. The higher figure is for AC-7A, meaning resistive and lightly inductive circuits such as heaters and lamp groups, and the lower one is for AC-7B, meaning small motors of appliance type. Industrial motors with heavy starting current are outside the intent of both categories and belong on a motor contactor with an overload relay.

Electrical durability in the datasheet: 100000 cycles IEC/EN 61095 40 A 50 Hz AC-7A; 30000 cycles IEC/EN 61095 15 A 50 Hz AC-7B; 30000 cycles IEC/EN 61095 50 Hz AC-7C.

How the A9C20842 compares with neighbouring iCT contactors

The A9C20838 differs in poles 4P against 2P here; contacts 2 NO + 2 NC against 2 NO here; current 25 A AC-7A against 40 A AC-7A here. The A9C20843 differs in poles 3P against 2P here; contacts 3 NO against 2 NO here; width 54 mm against 36 mm here.

The table below lists the iCT references of this group with their main differences so that a purchase order can be checked against the family.

Selection checklist for the A9C20842

• For heater loads near 40 A confirm continuous duty and supply cable size separately from the contactor rating.
• Use the 3.5 N.m torque on power terminals so that a hot cabinet does not loosen the connection.
• Match coil voltage and frequency to the control supply; this reference uses 220 to 240 V AC 50 Hz.
• Check the width of 36 mm (4 pitches) against free rail space and spare gaps for heat.
• Confirm the number of operations per day stays within the datasheet figure.

Mounting, wiring and maintenance of the A9C20842

During commissioning, energise the coil with the load circuit isolated and watch the action indicator; the datasheet lists local signalling by an action indicator on the front. Then close the load circuit and measure current and voltage drop. Switching frequency is limited to 100 switching operations/day, so check that a control program, a time switch or a building management output does not chatter the contactor many times per hour.

The datasheet lists the environment as -5 to 60 °C in operation and -40 to 70 °C in storage, relative humidity of 95 % at 55 °C, an altitude limit of 2000 m and pollution degree 2.

Where the A9C20842 is used in Oman and the GCC

At 40 A a two-pole contactor often serves commercial water heating in hotels, large villas and laundries, where a 9 kW element at 230 V draws about 39 A. The user must still check the AC-7A category, which is suitable for resistive and slightly inductive loads, and use a proper motor contactor if the load is a motor.

Where the contactor is mounted in a modular enclosure, the datasheet states that the protection degree is IP40 for the enclosure and IP20 for the device alone. Terminals must stay accessible after fitting, and the cable gland arrangement should keep the live terminals out of reach of unauthorised persons.

Information to send with an RFQ for the A9C20842

• Full reference (A9C20842) and quantity required
• Supply and control voltage at site, with the frequency
• Existing panel, rail and neighbouring devices it must fit beside
• Delivery location and timing
• Whether it is a spare, a like-for-like replacement or a new installation
• Load type and current: lighting, heating or motor-type

Documents and quotation

A datasheet for the A9C20842 is attached on this page. It lists the electrical, mechanical and environmental data summarised above, and it should be read together with the manufacturer’s installation instructions for the final design.

Send us the part number, quantity and application and we will confirm availability and a quotation. Seven Star LLC is an independent supplier in Muscat and is not affiliated with the manufacturer.