Group 31 Compact Valve Actuators

General Specifications

Output Torque and Timing

Model #	Torque (lb-ft)	Stroke Time (sec./90°) (60 Hz)	Stroke Time (sec./90°) (50 Hz)
31-M50, 31-350, 31-250	30	24	29
31-M30, 31-330, 31-230	15	18	22

Specifications common to all models:

Drive Power	120 Vac, single-phase, 50 or 60 Hz, 0.5A, 60 Watts
Operating Conditions	–40° to 65° C. (–40° to 150° F.) 0 to 99% relative humidity
Action on Loss of Power	Stays in place.
Handwheel	Provides manual operation without electrical power. Non-rotating during automatic operation, does not require declutching mechanism.
Motor	120 V ac, single-phase, no burnout, noncoasting. Capable of 60 starts per minute.
Gear Train	Precision cut, heat-treated alloy steel and ductile iron. Self-locking and self-releasing, able to hold position at 150% rated torque.
Mechanical Stops	Prevent overtravel during automatic or manual operation. Mechanical stops are external to the drive.
Drive Net Weight	25 lbs.
Max. Overhung Load	500 lbs

Switches

Cam controlled, field adjustable. Two limit switches (S3 & S4) open the motor circuit at end-of travel limits. Two auxiliary switches (S1 & S2) provied external signaling as specified through connections made at the terminal board. All four switches are SPDT and are rated for 1 amp at 120 V ac.

Enclosure

Precision machined aluminum alloy castings, painted with corrosion resistant polyurethane paint. All units meet NEMA 4 specifications and are also available FM approved for use in CLass 1, Div. 1, Group D; Class II, Div. 1, Groups E, F, & G; and Class III, Div.'s 1 & 2 hazardous locations.

Specifications for Control Option 3 drives (Models 31-M50 and 31-M30):

Demand Input Signal Range	4–20 mA OR 1–5 V dc
Signal Span Adjust	50% to 125% of 4 V span
Signal Zero Adjust	Up to 120% of span Split Signal Range: 4-12 mA or 12-20 mA
Deadband	1% of span
Sensitivity	0.2% of span
Feedback Signal *	4–20 mA OR 1–5 V dc
Output Stability for Temperature Change	+/- 0.03%/°C of Span for -40°C to 50°C
Stall Relay Contacts	Form A, 10 volt-amps at 120 V ac or dc
Action on Loss of Input Signal (Power On)	Stays in place or runs to any preset position (configurable).
Action on Stall	Relay contacts open after 68 seconds of stall, remote signal available. Power to motor is turned off.
Handswitch	Permits local operation, independent of controller signal. The handswitch is located beneath the control module cover on the control board.

Specifications for Control Option 2 drives (Models 31-350 and 31-330):

Feedback Signal *	4–20 mA OR 1–5 V dc
Output Stability for Temperature Change	+/- 0.03%/°C of Span for -40°C to 50°C

* Feedback may be configured as a two wire transmitter or as a four wire active signal source. Two wire systems require a customer supplied external power supply. Four wire systems require 120 V ac supply to the drive.