Model SRC — Zero Speed Control


The Model SRC is a direct drive control that indicates when rotating equipment has ceased to turn. The output contacts of the Model CMS can control up to two separate circuits – one for machinery shutdown and one for an alarm.


The Model SRC provides a means of protection to prevent compound damage from inoperative or failed equipment due to a lack of rotation.

Technical Specifications

  • The housing is cast aluminum, with optional epoxy or polyester powder coating available (for additional corrosion resistance).
  • The unit can be connected to rotating equipment by means of a stub shaft and flexible coupling.
  • The unit is mounted on the conveyor by drilling (4) 5/16" diameter holes.
  • General purpose (weather-proof) units and explosion-proof units have (2) 3/4" NPT conduit openings.
  • The standard unit has 120 VAC power input (120 VAC transformer). Optional 240 VAC power input (240 VAC transformer) and 24V AC/DC (transformer-less) available upon request.
  • The unit has a dry, unpowered DP/DT relay rated for 3A @ 120 VAC, 240 VAC, and 480 VAC.
  • The unit is bi-directional – it will detect motion or loss of motion in either direction.
  • The standard unit has a 12-segment brass encoder disk. A special 50-segment brass encoder disk can be supplied for low RPM applications (5 RPM or less). Specify "-50".
  • The operating temperature class is T6 (85°C [185°F]).
  • The maximum ambient temperature is 55°C [131°F].
  • The maximum operating speed is 1000 RPM.
  • The general purpose units are rated NEMA Type 4/4X weather-proof and corrosion-resistant, and explosion-proof units are rated NEMA Type 7/9 for vapor explosion-proof and dust ignition-proof (Class I, Div 1, Groups C & D; Class II, Div 1, Groups F & G).
  • The general purpose controls are IP65 compliant.
  • Most models are cULus Certified.


*Prices subject to change without notice.

ModelDescriptionShipping Weight (lbs.)Price
SRC-1GGeneral Purpose, 120 VAC, 1 DP/DT Relay7$375.00
SRC-1XExplosion Proof, 120 VAC, 1 DP/DT Relay7$410.00
SRC-2GGeneral Purpose, 240 VAC, 1 DP/DT Relay7$408.00
SRC-2XExplosion Proof, 240 VAC, 1 DP/DT Relay7$446.00
SRC-3GGeneral Purpose, 24V AC/DC, 1 DP/DT Relay7$374.00
SRC-3XExplosion Proof, 24V AC/DC, 1 DP/DT Relay7$413.00

Epoxy coating, add $12.00, add "E" to end of model number.

For 5 RPM or less, use low speed 50 segment disk, add $24.00, add "-50" to end of model number.


303Stub Shaft0.5$11.50
304Flexible Coupling0.5$48.00
305Coupling Guard0.5$30.00
310Mounting Bracket1.0$17.00
311Bearing Bracket2.5$67.00
312Bearing Bracket6.0$67.00
313Bearing Bracket10.0$67.00


CMS-10120 VAC electronics assembly1.5$141.00
CMS-20240 VAC electronics assembly1.5$161.00
CMS-3024V AC/DC electronics assembly1.5$139.00