Speed Switches


Speed switches are used to monitor engine rpm in automatic diesel engine overspeed protection systems.  In the event of an engine overspeed condition, the speed switch will immediately take action to shut down the diesel engine.  We have a several types of switches for use in a wide range of automatic shutdown systems including electric, hazardous area electric, and hydro-mechanical switches.

4110 Hydro-Mechanical Overspeed Sensing Valve

Adjustable range: 800 - 4200 RPM  
Repeatability: +/- 2%  
Body: Gulfproofed (anodized) aluminum
Internals: Steel and stainless steel
Seals: Viton (oil) Buna N/Nitrile (air)
Two-way valve thread: 1/4” NPT  
Flow Coefficient: Kv = 0.56 Cv = 0.65
Max. valve pressure: 5.5 bar 80 psi
Accuracy: +/- 5%  
Mounting thread (std): 7/8 - 18 heavy duty SAE  

See datasheet for complete specifications

CSX-300 Control Unit

CSX-300 Control Unit

Inputs & Outputs: CSX-300 CSX-310
Power: 12 VDC 24 VDC
Speed signal: Magnetic pickup / alternator Magnetic pickup / alternator
Outputs to shutoff valve:

46A/12 VDC (pull)

1.1A/12 VDC (hold)

25A/24 VDC (pull)

0.5A/24 VDC (hold)

Manual shutdown: CSX-840 (status indicator) CSX-840 (status indicator)
Optional sensor circuits: Max. 5 (CSX-301) Max. 5 (CSX-311)
Material: Aluminum

6¼” x 3⅛” x 3⅜” (160 x 80 x 60mm)

Ingress protection: IP66 with cable glands


RevGuard 2 Speed Switch

REVGUARD 2 Speed Switch

Input power:

Supply voltage:

12-32 VDC

with reverse polarity protection

Input signal:

Frequency range:

Input signal type:


100 Hz - 10,000 Hz

Sine wave or square wave

See datasheet for complete specifications.