Schneider Electric A9C20844 iCT 40 A 4NO 220-240 V Contactor

A9C20844: four-pole 40 A contactor with neutral switching

The A9C20844 is a Schneider Electric Acti9 contactor listed in the datasheet as: contactor iCT – 4 poles – 4 NO – 40 A – 220..240 V AC. The A9C20844 offers four normally open poles at 40 A in a six-pitch body, so three phases and neutral can all be switched by one device. It targets larger single-phase and three-phase-plus-neutral circuits where a full disconnection is required. Seven Star LLC supplies the A9C20844 in Oman and the GCC as an independent supplier based in Muscat.

From the datasheet: A9C family, 40 A rating, four poles with four normally open contacts (4P, 4 NO), 220 to 240 V AC 50 Hz coil. The operational voltage is 400 V AC at 50 Hz, with 6.5 VA hold-in and 53 VA inrush on the coil, the same as the three-pole sibling.

Technical specifications of the A9C20844

Power circuit and coil data of the A9C20844

The rated operational current is 40 A AC-7A; 15 A AC-7B. Rated operational voltage: 400 V AC 50 Hz. Maximum power figure: 2.1 W at 400 V AC. Coil voltage: 220 to 240 V AC 50 Hz. Hold-in consumption: 6.5 VA. Inrush consumption: 53 VA. Rated insulation voltage: 500 V AC 50/60 Hz. Rated impulse withstand voltage: 4 kV. Mechanical durability: 1000000 cycles.

Compared with the three-pole A9C20843, the extra pole does not change body width or coil data; what changes is the contact logic. The neutral pole is wired in the same way as the phases and opens at the same time. For a four-wire supply this removes the question of a live neutral at a switched load, a common requirement in public buildings and on construction sites.

AC-7A and AC-7B ratings of the A9C20844: reading the load categories

The datasheet lists the load ratings by category from IEC/EN 61095. AC-7A covers slightly inductive loads of household and similar use, which is where lighting, heating and resistive circuits belong. AC-7B is the rating for the motor loads of household appliances and is always much lower than the AC-7A figure. A designer who reads only the headline current can therefore overload the contacts with a motor-type load; reading the category avoids that.

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 A9C20844 compares with neighbouring iCT contactors

The A9C20843 differs in poles 3P against 4P here; contacts 3 NO against 4 NO here. The A9C20864 differs in current 63 A AC-7A against 40 A AC-7A 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 A9C20844

• Verify the supply is four-wire and that breaking the neutral is permitted by the wiring rules in force.
• Check that the control source can deliver the 53 VA inrush of the coil.
• Match coil voltage and frequency to the control supply; this reference uses 220 to 240 V AC 50 Hz.
• Check the width of 54 mm (6 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 A9C20844

Mount the contactor on a 35 mm DIN rail by clipping it on; no screws are needed for the body. Use the tightening torques from the datasheet: Control circuit: 0.8 N.m, Power circuit: 3.5 N.m. Leave a gap beside the contactor when several are fitted in a row, because every energised coil dissipates heat, and in a warm Gulf plant room the margin to the -5 to 60 °C operating limit is often small. Label the coil terminals A1 and A2 clearly, since a mistaken coil connection is the most common commissioning error.

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 A9C20844 is used in Oman and the GCC

Four-pole 40 A contactors are used for three-phase lighting feeders with neutral, small data-room supply switching and hotel floor distribution, where a building management system or a time controller gives the on and off command. In shopping centres around Muscat they are typical of the night-mode switching of display and signage circuits.

Before ordering, compare the load with the AC-7A and AC-7B categories in the datasheet and the thermal behaviour of the whole board. A full row of 40 A contactors at six pitches each develops significant heat; space them or ventilate the board.

Information to send with an RFQ for the A9C20844

• Full reference (A9C20844) 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 A9C20844 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.