Schneider Electric 8770003000 Damper Actuator 4 N.m

8770003000: LF24-SR spring-return damper actuator, 4 N.m

The 8770003000 is a Schneider Electric rotary electric actuator for air dampers. The datasheet lists 4 N.m of torque, proportional/modulating control, spring return, a 24 V AC/DC supply and a 1 m lead. It belongs to the LF series rather than MD, and it is the only reference in this group that combines modulating control with a spring that returns the damper in 20 seconds.

Seven Star LLC supplies the 8770003000 as an independent supplier in Oman and the GCC to HVAC contractors, building-management integrators and facility teams. The datasheet carries no ordering-code table, so the series and function above are read from the product title and specification, not from a decoded part number.

Technical specifications of the 8770003000

Supply, power draw and wiring

The supply is 24 V AC/DC, and the datasheet gives a transformer rating of 5 VA. Power consumption while moving is 2.5 W and the hold-in value is 1 W. Add the transformer ratings of all actuators on a common 24 V supply, not just the watts, and leave headroom because several spring or non-spring units may start together at the beginning of a ventilation cycle.

The insulation class is Class III, so the device is intended for extra-low-voltage supply only and mains voltage must never be connected. The lead length is 1 m; extend it only inside a suitable terminal enclosure and label each lead with the damper tag at the panel end so a technician can trace a fault from the controller to the shaft.

Selection checklist for the 8770003000

• Torque: the damper maker requirement must stay below 4 N.m with margin.
• Signal: proportional/modulating; match the controller output type.
• Failure position: spring return.
• Supply: 24 V AC/DC and a transformer sized for 5 VA per actuator.
• Shaft: confirm the damper shaft size and clamp range.
• Housing: IP54; check it against the installation location.

Installation and commissioning of the 8770003000

Fit the actuator to the damper shaft, set the end stop or mechanical limits, and wire the 1 m lead to a correctly rated 24 V supply. Cycle the damper under control and watch the whole travel for binding; an actuator that struggles to reach an end position points to a mechanical fault and should not be solved by raising the supply.

Keep spares of this unit for dampers that are critical to a plant or a hospital, because a seized damper usually shows itself on the first hot-weather commissioning test, when time is short. At each filter change inspect the shaft coupling and the cable entry for dust.

Torque and damper sizing for the 8770003000

4 N.m is a light-duty rating intended for a single small damper or a short run of linked blades. The damper manufacturer states the torque each blade section needs, normally at the highest air velocity and differential pressure in the duct, and the actuator rating has to exceed the sum for the sections it drives with margin. Dust build-up and ageing seals raise the torque requirement over the years, so a unit chosen at the limit tends to become the maintenance call.

The actuator mounts directly on the damper shaft with a clamp and rotates through 95 degrees. Check the shaft size and shape against the clamp range before ordering, and confirm that the actuator and damper are mounted so that the rotation direction matches the closed position on the damper.

How the 8770003000 is commanded

Control is proportional. The building controller sends a 2–10 V DC command and the actuator turns the damper shaft to the matching angle across its 95-degree stroke. The datasheet lists no feedback output for this reference, so confirmation of position has to come from the damper itself or from a separate sensor.

Because the signal is analogue, a mixing or economiser strategy can hold the damper at any intermediate position. Keep the signal cable away from power wiring and confirm the controller output can drive the input of the actuator without a separate resistor.

Failure position and spring behaviour of the 8770003000

Spring return is the defining feature of this reference. When the supply is lost the internal spring drives the damper to its safe end position, and the datasheet gives the spring return timing as 20 s. That behaviour is what fire, smoke, freeze-protection and outside-air shut-off duties depend on, because the damper reaches its safe state without any electrical supply.

During a project, test the return by cutting power with the damper at the opposite end of travel and timing it against the specification. The rotation can be trimmed between 37 and 100 degrees to fit the damper. Record the result with the damper tag so that the next maintenance visit has a reference.

Information to send with an RFQ for the 8770003000

• Exact reference 8770003000 and the quantity.
• Damper torque requirement and shaft size or type.
• Control signal, supply voltage and whether feedback is needed.
• Fail-safe requirement (spring return or hold position).
• Delivery location and project schedule.

Documents and quotation

The manufacturer datasheet for the 8770003000 is attached on this page and carries the specification summarised above. Check the revision date printed on it against your project documents before you rely on a figure.

Send us the reference 8770003000, the quantity and the delivery location, and Seven Star LLC will reply to your request. We are an independent supplier based in Muscat and we confirm availability and lead time per enquiry.