Schischek RedMax-M-F3 Size M Actuator for ATEX Zones 2 and 22

Spring-return actuator for zone 2 and 22 locations

The Schischek RedMax-M-F3 is the zone 2 and zone 22 version of the size M F3 actuator. Where ExMax types are tested for zones 1, 2, 21 and 22, the RedMax line is tested for zone 2 (gas) and zone 22 (dust) only, which suits less demanding hazardous-area locations. It offers a spring return of about 3 s per 90 degrees with 24 Nm (30-F3) or 40 Nm (50-F3), on-off control and a 24 to 240 VAC/DC supply.

Technical specifications

RedMax or ExMax

The two lines share the same size M housing and the same F3 performance, but the RedMax markings are category 3 (Gc and Dc). Do not substitute one for the other without checking the zone of the installation: a zone 1 location needs ExMax. The terminal boxes for RedMax are the RedBox series, with RedSwitch as the external auxiliary switch, according to the accessory list.

What to confirm before ordering

Give the zone and gas or dust group, the temperature class needed, torque, suffix, supply and damper shaft size. The datasheet notes that a terminal box is needed for connection in hazardous areas. The Ex-i circuit in the BF3 version is for the ExPro-TT temperature trigger.

Related Schischek products: Schischek ExMax-M-F3 Size M Ex Actuator, 3 s Spring Return, Schischek ExMax-M-BF Size M Ex Actuator with Ex-i Trip Circuit, Schischek ExMax-S-BF Ex Rotary Actuator with Ex-i Trip Circuit, Schischek ExMax-M-Y Size M Modulating Ex Rotary Actuator, Schischek ExMax-S-3P Explosion-Proof Rotary Actuator, Size S and Schischek ExMax-M-3P Explosion-Proof Rotary Actuator, Size M.

Key features listed by Schischek

The RedMax size M datasheet describes the actuators as electrical, explosion-proof quarter-turn actuators, ATEX tested to directive 2014/34/EU for zones 2 and 22, for all types of gases, mists, vapours and dusts in those zones. The F3 version is the on-off model with spring return. The main features are:

• Universal supply unit, self-adapting to 24 to 240 V AC/DC (±10%), 50 to 60 Hz.
• Motor running time selectable on site: 40, 60, 90, 120 or 150 s per 90°. No special tools are needed for adjustment.
• 95° angle of rotation including about 5° pretension, with mechanical position indication.
• Brushless DC motor and a gear made of stainless steel and sintered metal; 100% overload protected.
• Direct coupling to the damper shaft through a 16 × 16 mm double square connection. Reduction parts AR-16-xx adapt to 14 or 12 mm shafts.
• Robust aluminium housing, IP66/IP67, about 288 × 149 × 116 mm and about 9.5 kg. A seawater-resistant coated version (-CTM) and a stainless steel housing (-VAM) are available as special options.
• Manual override included.

Torque and spring return data

The size M housing is offered in two torque versions. The RedMax-30-F3 has a minimum motor torque of 30 Nm and a spring torque of about 24 Nm; the RedMax-50-F3 has 50 Nm motor torque and about 40 Nm spring torque. Schischek specifies the minimum external load for dimensioning as 8 Nm and 15 Nm respectively. On voltage interruption, or when line 3 is opened, the spring returns the damper with a response time of up to 1 s, and the spring return running time is about 3 s per 90°. The datasheet states a minimum of 1,000 safety operations at 3 s, depending on damper construction and ambient conditions. Holding power is approximately 7 to 17 W depending on the supply voltage. The working direction is selected by mounting the actuator left or right on the shaft.

Related versions and accessories

The SF3 version adds two integrated, potential-free auxiliary switches at 5° and 85°, and the BF3 version adds an intrinsically safe Ex-i circuit for direct connection of the ExPro-TT safety temperature trigger for fire dampers via an M12 quick connection. Accessories include RedBox terminal boxes for zones 2 and 22, the MKK-M mounting bracket, RedSwitch external auxiliary switches and nickel-plated cable glands (Kit-S8). Typical applications are safety, fire and shut-off dampers, VAV systems, ball valves and throttle valves in HVAC systems of chemical, pharmaceutical, industrial and offshore or onshore plants.

Information to include with an enquiry

To select the correct RedMax model, please send the damper or valve type, the torque it needs, the shaft size and shape, the hazardous area classification (zone 2 or zone 22, gas group and temperature class), the supply voltage and the required running time. Also state whether you need auxiliary switches, a fire damper temperature trigger, a terminal box or a seawater-resistant or stainless steel housing for offshore or coastal installations, so the complete package can be quoted together.

Documents and quotation

Use the download on this page to open the manufacturer’s datasheet PUB113-463 for the RedMax-M-F3. Requests are handled by Seven Star LLC, an independent supplier based in Muscat. Send the complete type code with suffix, torque and supply and we reply with price, lead time and availability. Other actuators are listed in Valve Actuators.