Somfy Simu T8S DMI 280Nm Motor Fit and Torque Guide

Installers reach for a Type 8 operator once a rolling closure outgrows a Type 6. The Somfy Simu T8S DMI 280Nm Diameter 94mm 120V Slim Head (2008303) sits near the top of that range, and it answers a mechanical question before it answers a torque question. The barrel has to be 94mm. Somfy builds this operator on a 3.15 in body that carries a 94mm drive wheel, and the drive plus idle insert you order have to match that barrel.

Specify the tube first. Torque second.

Tube diameter decides this motor before torque does

Somfy publishes the T8S DMI 280Nm as an axial tubular operator with a 3.15 in diameter body and an unwrapped envelope of 27.95 in by 5.12 in by 5.12 in. The 94mm figure in the product name points at the round drive and the idle insert, not the motor casing. You pair this ref with the T8 94mm round drive and the matching 94mm idle insert at the far end of the shaft.

Somfy builds sibling refs for 97mm and 124mm barrels. Ordering a 97mm set for a 94mm tube leaves the drive loose on the shaft, and the shutter will track off square under load. Measure the barrel, then order the drive and the insert as a pair.

The slim head keeps the motor end of the assembly short inside the hood. Fabricators who work in tight headboxes ask for that head style because it shortens the dead space beside the bracket.

Doors and grilles this operator drives

Somfy classifies the T8S DMI 280Nm for industrial and commercial closures and rolling shutters. At 280 Nm the motor carries heavy slat shutters, security grilles, warehouse closures and fire station doors. Somfy rates it for 10 cycles per day, which frames it as a commercial duty operator rather than a high-traffic parking gate motor.

Two traits separate this ref from the rest of the T8S line. It runs 280 Nm instead of the 200 Nm that the 94mm T8S starts at, and the DMI head carries a manual override so staff can move the curtain during an outage. Buildings that keep an opening in service through a power loss need that second trait more than they need the extra torque.

Verified specifications

Figures published by Somfy for ref 2008303.

Manual override on the DMI head

DMI marks the override head in the Simu range. Somfy lists a chain hoist built for T8S DMI motors, ref 9019458, along with a separate chain, and a T8-S DMI eye and hex shaft in 7mm by 400mm. Staff turn the shaft or pull the chain to raise a shutter after a power cut or a controller fault.

Plan the override at the design stage. The hoist and the shaft both need clearance beside the motor head and a reachable position at floor level, and retrofitting that clearance into a finished hood costs more than allowing for it on the drawing. Confirm the override hardware against the head on the motor you receive before you cut anything.

A fire exit, a loading dock and a secure store room all gain from an override on the shutter that closes them. Code officials often ask about that path during sign off.

Drives, inserts and the operator bracket

Somfy lists the T8-S / T8-S DMI Operator Bracket (9018069) against this ref. The bracket carries the motor head and transfers reaction torque into the structure, and the T8-S and T8-S DMI heads share it. Fix it into solid substrate. A 280 Nm operator puts real load into whatever holds the head.

At the shaft, Somfy names the T8 94mm round drive for the 200 Nm to 280 Nm band plus the 94mm idle insert. Somfy also publishes 97mm and 124mm round sets with their own inserts for the wider barrels in the range. Order the drive, the insert and the bracket together with the motor so nothing holds up the install.

Wiring and control

The T8S DMI 280Nm runs on four wires at 120V. Common, up, down and ground land on a momentary switch, a key switch or a relay card. Nothing pairs and nothing programs by radio. An electrician sets the limits at the head and the motor holds them.

Bench testing saves a second trip up the ladder. The Somfy Standard Motor Tester Cable, 4-Wire (9012116) lets you run the motor and set limits on the ground before the tube goes into the brackets. Somfy lists that cable against this ref.

Feed the motor from a circuit that supports 6.9 A draw at 820 W. The 4 minute thermal time tells you the operator stops itself after sustained running, and it restarts once the windings cool.

Safety brakes on a heavy curtain

Somfy lists six safety brakes against this ref, from 258 Nm through 3000 Nm. Two of them sit in stock here:

• Somfy Simu Safety Brake 404Nm Torque (2005627) for curtains in the band above this motor's rating
• Somfy Simu Safety Brake M10A, 1000 Nm Torque (2005629) for heavier assemblies where the curtain weight calls for more holding capacity

Size the brake from the curtain, not from the motor. A specifier works out the dead load on the shaft, then picks the brake that holds it. Somfy publishes the full ladder so the choice follows the calculation.

Pair the Simu T8S DMI 280Nm Diameter 94mm 120V Slim Head (2008303) with the 94mm round drive, the 94mm idle insert, the T8-S operator bracket and the brake your load calculation calls for. Add the tester cable if your crew sets limits on the bench. Somfy backs the motor with a 5 year warranty.

Frequently asked questions

What tube does the Simu T8S DMI 280Nm fit?

It fits a 94mm barrel. Somfy pairs this ref with the T8 94mm round drive for 200 Nm to 280 Nm and the 94mm idle insert. The motor body itself measures 3.15 in in diameter. Somfy builds separate refs for 97mm and 124mm tubes, so match the drive and insert to the barrel on the job.

What does DMI mean on a Simu motor?

DMI marks the manual override head. Somfy lists a chain hoist for T8S DMI motors, ref 9019458, and a T8-S DMI eye and hex shaft in 7mm by 400mm. Staff use the hoist or the shaft to move the curtain during a power outage or a control fault, then return the shutter to powered operation.

Does this motor work with RTS remotes?

No. The T8S DMI 280Nm is a wired 4-wire operator with no radio receiver. Control comes from a momentary switch, a key switch or a relay output at 120V. An installer who wants radio control adds an external receiver on the supply side, wired to the same four conductors.

How much power does the T8S DMI 280Nm draw?

Somfy publishes 6.9 A rated current and 820 W in operation on a 120V/60Hz supply, with a voltage range of 108 V to 132 V and 0 W in standby. Thermal time runs 4 minutes. Size the branch circuit and the switch contacts for that draw before the crew pulls wire.

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