Technical Data 1405 Power Supply24 VAC, ±20%, 50/60 Hz, 24 VDC, ±10% Power consumption in operation2.5 W Power consumption in rest position 1 W Transformer sizing5 VA (class 2 power source) Shaft Diameter3/8...1/2” round, centers on 1/2” Electrical Connection18 GA plenum cable, 3 ft [1 m], with 1/2” conduit connector Overload Protectionelectronic throughout 0...95° rotation Electrical Protectionactuators are double insulated Operating Range2...10 V, 4...20 mA w/ ZG-R01 (500 Ω , 1/4 W resistor) Input Impedance100 k Ω for 2...10 V (0.1 mA), 500 Ω for 4...20 mA Position Feedback2...10 V, Max. 0.7 mA Angle of rotationMax. 95°, Torque motor35 in-lb [4 Nm] Direction of motion motorselectable with switch 0/1 Direction of motion fail-safereversible with cw/ccw mounting Position indicationMechanical Running Time (Motor)150 s constant, independent of load Running time fail-safe<25 s @ -4...122°F [-20...50°C], <60 s @ -22°F [-30°C] Ambient humiditymax. 95% r.H., non-condensing Ambient temperature-22...122°F [-30...50°C] Storage temperature-40...176°F [-40...80°C] Degree of ProtectionIP54, NEMA 2 Housing materialgalvanized steel Agency ListingcULus acc. To UL 873 and CAN/CSA C22.2 No. 24-93 Noise level, motor30 dB(A) Noise level, fail-safe62 dB(A) Servicingmaintenance-free Quality StandardISO 9001 Weight3.4 lb [1.5 kg] †Rated Impulse Voltage 800V, Type of action 1.AA, Control Pollution Degree 3 Torque min. 35 in-lb, for control of air dampers. Application For fail-safe, modulating control of dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturer’s specifications. The actuator is mounted directly to a damper shaft from 3/8” up to 1/2” in diameter by means of its universal clamp, 1/2” shaft centered at delivery. For shafts up to 3/4” use K6-1 accessory. A crank arm and several mounting brackets are available for applications where the actuator cannot be direct coupled to the damper shaft. The actuator operates in response to a 2 to 10 VDC, or with the addition of a 500Ω resistor, a 4 to 20 mA control input from an electronic controller or positioner. A 2 to 10 VDC feedback signal is provided for position indication. Operation The LF series actuators provide true spring return operation for reliable fail-safe application and positive close-off on air tight dampers. The spring return system provides consistent torque to the damper with, and without, power applied to the actuator. The LF series provides 95° of rotation and is provided with a graduated position indicator showing 0 to 95°. The LF24-SR US uses a brushless DC motor which is controlled by an Application Specific Integrated Circuit (ASIC) and a microprocessor. The microprocessor provides the intelligence to the ASIC to provide a constant rotation rate and to know the actuator’s exact fail-safe position. The ASIC monitors and controls the brushless DC motor’s rotation and provides a digital rotation sensing function to prevent damage to the actuator in a stall condition. The actuator may be stalled anywhere in its normal rotation without the need of mechanical end switches. Power consumption is reduced in holding mode. Dimensions (Inches[mm]) 2.74" [ 69.6] 2.25" [ 57.1] 0.73" [ 18.54] 3.23" [ 82] 0.25" [ 6.25] 1.15" [ 29.3] 2.3" [ 58.42] 3.15" [ 80] 7.66 " [ 194.501] 0.2" [ 5.08 ] 0.98 " [ 25] 4.72 " [ 120] 0.39 " [ 10] 0.97" [ 24.6] 3.86" [ 98] 1.69 " [ 43] 3.66 " [ 93] 6.1 " [ 155] 3.66 " [ 93] 6.1 " [ 155] 0.26 " [ 6.5] LF24-SR US Technical Data Sheet Modulating, Spring Return, AC 24 V/DC, for DC 2...10 V or 4...20 mA Control Signal 800-543-9038 USA866-805-7089 CANADA203-791-8396 LATIN AMERICA / CARIBBEAN Date created, 02/10/2020 - Subject to change. © Belimo Aircontrols (USA), Inc.Accessories AV6-20Shaft extension K6 USStandard LF clamp (3/8” to 1/2”). K6-1Shaft clamp reversible KG10ABall joint KG8Ball joint KH8Damper crank arm KH-LFActuator arm KH-LFVV-bolt Kit for KH-LF. LF-PAnti-rotation bracket LF. SH10Push rod for KG10A ball joint (36” L, 3/8” diameter). SH8Push rod for KG6 & KG8 ball joints (36” L, 5/16” diameter). TOOL-068 mm and 10 mm wrench. ZDB-LFAngle of rotation limiter ZF8-LFForm fit adapter ZG-109Right angle bracket for ZS-260. ZG-110Stand-off bracket for ZS-260. ZG-112LF right angle bracket 4-1/2x5-1/2x2-1/2” (HxWxD). ZG-DC1Damper clip for damper blade, 3.5” width. ZG-DC2Damper clip for damper blade, 6” width. ZG-LF112LF crankarm adaptor kit (includes ZG-112). ZG-LF2LF crankarm adaptor kit (T bracket included). ZG-LMSA-1Shaft extension for 3/8” diameter shafts (4” L). ZG-LMSA-1/2-5Shaft extension for 1/2” diameter shafts (5” L). ZS-100Weather shield - galvaneal 13x8x6” (LxWxD). ZS-101Base plate for ZS-100. ZS-150Weather shield - PC w/ foam seal 16x8-3/8x4” (LxWxD). ZS-260Explosion proof housing. ZS-300NEMA 4X, 304 stainless steel enclosure. ZS-300-5NEMA 4X, 316L stainless steel enclosure. ZS-300-C11/2” shaft adaptor, standard wtih ZS-300(-5). ZS-300-C23/4” shaft adaptor for ZS-300(-5). ZS-300-C31” shaft adaptor for ZS-300(-5). IRM-100Input rescaling module for modulating actuators. P475Shaft mount, non-Mercury aux. switch for 1/2” dia. shafts. P475-1Shaft mount, non-Mercury aux. switch for 1” dia. shafts. PS-100Low voltage and control signal simulator. PTA-250Pulse width modulation interface for modulating actuators. SGA24Positioners suitable for use with the modulating damper actuators LM..A-SR, NM..A-SR, SM..A-SR and GM..A-SR SGF24Positioners suitable for use with the modulating damper actuators LM..A-SR, NM..A-SR, SM..A-SR and GM..A-SR ZG-R014 to 20 mA adaptor, 500Ω, 1/4 W resistor w 6” pigtail wires. ZG-R0250% voltage divider kit (resistors with wires). ZG-SGFMounting plate for SGF. ZG-X40120 to 24 VAC, 40 VA transformer. Typical Specification Spring return control damper actuators shall be direct coupled type which require no crank arm and linkage and be capable of direct mounting to a shaft up to a 3/4” diameter and center on a 1/2” shaft (default). Actuator shall deliver a minimum output torque of 35 in-lbs. The actuator must provide modulating damper control in response to a 2 to 10 VDC or, with the addition of a 500 Ω resistor, a 4 to 20 mA control input from an electronic controller. Actuators shall use a brushless DC motor controlled by a microprocessor and be protected from overload at all angles of rotation. Run time shall be constant, and independent of torque. A 2 to 10 feedback signal shall be provided for position feedback. The actuator must be designed so that they may be used for either clockwise or counter clockwise failsafe operation. Actuators shall be cULus listed, have a 5 year warranty, and be manufactured under ISO 9001 International Quality Control Standards. Actuators shall be as manufactured by Belimo. Blk (1) Common Red (2) + Hot Wht (3) Y Input, 2 to 10 V Grn (5) U Output Control Signal (+)VDC/mA (–) Feedback Signal (+) 2 to 10 VDC (–) Ω 500 Ω Line Volts 13 511 24 VAC Transformer 7 2 to 10 VDC / 4 to 20 mA control LF24-SR US Technical Data Sheet Modulating, Spring Return, AC 24 V/DC, for DC 2...10 V or 4...20 mA Control Signal 800-543-9038 USA866-805-7089 CANADA203-791-8396 LATIN AMERICA / CARIBBEAN Date created, 02/10/2020 - Subject to change. © Belimo Aircontrols (USA), Inc.Wiring Diagrams ! WARNING! LIVE ELECTRICAL COMPONENTS! During installation, testing, servicing and troubleshooting of this product, it may be necessary to work with live electrical components. Have a qualified licensed electrician or other individual who has been properly trained in handling live electrical components perform these tasks. Failure to follow all electrical safety precautions when exposed to live electrical components could result in death or serious injury. Meets cULus requirements without the need of an electrical ground connection. Provide overload protection and disconnect as required. Actuators may also be powered by 24 VDC. Only connect common to negative (-) leg of control circuits. A 500 Ω resistor (ZG-R01) converts the 4 to 20 mA control signal to 2 to 10 VDC. Actuators may be connected in parallel if not mechanically linked. Power consumption and input impedance must be observed. LF24-SR US Technical Data Sheet Modulating, Spring Return, AC 24 V/DC, for DC 2...10 V or 4...20 mA Control Signal 800-543-9038 USA866-805-7089 CANADA203-791-8396 LATIN AMERICA / CARIBBEAN Date created, 02/10/2020 - Subject to change. © Belimo Aircontrols (USA), Inc.Next >