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Honeywell S20 Series Spring Return Direct Coupled Actuator

Spring Return Direct Coupled Actuator
S20 Series

MS4120, MS7520, MS8120 Spring Return Direct Coupled Actuators (DCA) are used within heating, ventilating, and air-conditioning (HVAC) systems. They can drive a variety of quarter-turn, final control elements requiring spring return fail-safe operation.

• Brushless DC submotor with electronic stall protection for floating/ modulating models.
• Brush DC submotor with electronic stall protection for 2-position models.
• Self-centering shaft adapter (shaft coupling) for wide range of shaft sizes.
• Models available for use with two-position, single pole single throw (SPST), line- (Series 40) or low- (Series 80) voltage controls.
• Models available for use with floating or switched single-pole, double-throw (SPDT) (Series 60) controls.
• Models available for use with proportional current or voltage (Series 70) controls.
• Models available with combined floating/modulating control in a single device.
• Models available with adjustable zero and span.
• Models available with line-voltage internal end switches.
• Access cover to facilitate connectivity.
• Metal housing with built-in mechanical end limits.
• Spring return direction field-selectable.
• Shaft position indicator and scale.
• Manual winding capability with locking function.
• UL (cUL) listed and CE compliant.
• All Models are plenum-rated per UL873.

Select a link under the "item" tab below to order.

Cat #Control SignalNominal Driving @ 60 HzMaximum Spring ReturnDrivingHoldingSupply VoltageNumber of Internal Auxiliary SwitchFeedbackInput ImpedanceSwitch Ratings
MS4120A1001Two position; SPST45 sec20 sec60 VA13 VA100 to 250 Vac0
MS4120A1209Two position; SPST45 sec20 sec60 VA13 VA100 to 250 Vac2250 Vac, 5 A res (3 A ind)
MS7520A2007(0)2-10 Vdc (4-20 mA w/500 ohm resistor); Floating90 sec20 sec16 VA5 VA24 Vac ±20%02-10 Vdc (max. output: ±1.0 mA)145K ohm
MS7520A2205(0)2-10 Vdc (4-20 mA w/500 ohm resistor); Floating90 sec20 sec16 VA5 VA24 Vac ±20%22-10 Vdc (max. output: ±1.0 mA)145K ohm250 Vac, 5 A res (3 A ind)
MS7520H2208(0)2-10 Vdc (4-20 mA w/500 ohm resistor); Floating90 sec20 sec16 VA5 VA24 Vac ±20%22-10 Vdc (max. output: ±1.0 mA)145K ohm250 Vac, 5 A res (3 A ind)
MS8120A1007Two position; SPST45 sec20 sec40 VA8 VA24 Vac ±20%0
MS8120A1205Two position; SPST45 sec20 sec40 VA8 VA24 Vac ±20%2250 Vac, 5 A res (3 A ind)
Actuator Type Damper; Valve
Rotational Stroke 95 ±3 degrees
Fail Safe Mode Spring Return
Torque 175 lb-in. (20 Nm)
Maximum Stall Torque 300 lb-in. (34 Nm)
Spring Return Torque 175 lb-in. (20 Nm)
Spring Return Direction By orientation
External Auxiliary Switches Available Yes, SW2-US
Electrical Connections Enclosed screw terminal strip (22 to 14 AWG)
Environmental Rating NEMA2
Frequency 60 Hz
Manual operation Manual crank
Mounting Direct Coupled
Maximum Noise Rating, Holding (dBA @ 1m) 20 (no audible noise)
Maximum Noise Rating, Driving (dBA @ 1m) 40
Rotational Stroke Adjustment Mechanically limited 5 degree increments
Compatible Damper Shafts 3/8 to 1.06 round or 3/8 to 11/16 square (10 to 27 round or 10 to 18 square)
Shaft Adapter Type Self-centering clamping
Materials Aluminum housing, Plenum rated plastic access cover
Operating Humidity Range (% RH) 5 to 95% RH, non-condensing
Ambient Temperature Range -40 F to +140 F (-40 C to +60 C)
Storage Temperature Range -40 F to +158 F (-40 C to +70 C)
Weight 6 lb (2.72 kg)


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