Description
⚙️ Product Overview
The WARTSILA DESPEMES OV72H73-2 is an electronic diesel-engine speed measuring system designed for marine and stationary engine applications. DESPEMES provides engine-speed measurement together with relay functions used by the engine automation system.
The system uses contactless speed sensing and converts the sensor signal into a speed-proportional electrical signal. Its relay functions can be used for speed-dependent automation, alarm, control, and protective functions. The OV72H73-2 configuration includes the C1, C2, C3, and C4 functional sections identified in the product listing.
The listing identifies the unit as a used Wartsila DESPEMES system, model OV72H73-2, with Finland listed as the country of origin.
🔧 Key Features
- ⚓ Wartsila DESPEMES diesel-engine speed measuring system
- 🔢 Model: OV72H73-2
- 🏭 Designed for marine and stationary diesel engines
- 📈 Electronic, contactless engine-speed measurement
- ⚙️ Speed-proportional voltage output
- 🔔 Integrated speed-controlled relay functions
- 🔌 C1 power supply section
- 📊 C2 speed measuring converter section
- 🔄 C3 relay card section
- 🌡️ C4 NTC-related measuring section
- 🛠️ Suitable for maintenance and replacement of legacy Wartsila engine automation equipment
📊 Product Datasheet
| Parameter | Specification |
|---|---|
| Brand | WARTSILA |
| System | DESPEMES |
| Model | OV72H73-2 |
| Product Name | Diesel Engine Speed Measuring System |
| Application | Marine & stationary diesel engines |
| Functional Sections | C1 / C2 / C3 / C4 |
| C1 Function | DC/DC Power Supply |
| C2 Function | Engine Speed Measuring Converter |
| C3 Function | Relay Functions |
| C4 Function | NTC Measuring / Temperature-Related Section |
| Condition / Status | Used; insignificant signs of use reported |
| Country of Origin | Finland |
| Dimensions | System/rack configuration dependent |
| Weight | Verify actual unit |
| Power Supply | System-dependent; C1 supports DC input configurations |
🏭 Typical Applications
The DESPEMES system is intended for diesel-engine instrumentation and automation environments, particularly where engine speed must be continuously measured and converted into usable electrical signals for local or remote equipment.
Typical applications include:
- 🚢 Main marine diesel engines
- ⚓ Auxiliary engines and generator sets
- 🛳️ Engine-room automation
- 🏭 Stationary diesel power installations
- 🔔 Speed alarm and protection circuits
- ⚙️ Starting and fuel-control supervision
- 🌀 Turbocharger speed monitoring where configured
- 🛠️ Legacy Wartsila engine control and instrumentation systems
🔌 Control & Technical Functions
The DESPEMES architecture uses an inductive speed sensor to detect the passage of gear teeth. The resulting pulse frequency corresponds to engine rotational speed and is processed by the measuring converter.
The DESPEMES documentation identifies several important functions:
C1 – Power Supply
The C1 section provides the DC/DC power conversion required by the measuring system. The documented DESPEMES design includes 24 VDC-class and higher-voltage DC supply configurations depending on the system version.
C2 – Engine Speed Measuring Converter
The C2 section processes the engine-speed sensor signal and provides a speed-proportional output for connected instruments and automation functions.
C3 – Relay Card
The relay section provides speed-controlled relay functions. Relay switching points and delays can be adjusted according to the engine automation configuration.
C4 – NTC / Measuring Section
The C4 section is associated with the additional measuring function identified in the listing. The exact NTC channels and configuration should be confirmed against the installed card and engine documentation.
For compatible DESPEMES configurations, the system can also support additional turbocharger-speed measurement and relay functions.
🛠️ Installation & Maintenance
Before Installation
- Confirm the existing system is the same OV72H73-2 configuration.
- Compare PCB/card identification and revision information.
- Verify the vessel’s supply voltage before energizing the system.
- Inspect connectors, terminals, and wiring for corrosion or oxidation.
- Confirm the installed speed sensor type and mechanical mounting arrangement.
Speed Sensor Check
The inductive pickup should be correctly positioned relative to the engine gear teeth. Incorrect sensor clearance can result in unstable or missing speed signals.
Check:
- Sensor mounting
- Sensing gap
- Cable condition
- Connector contacts
- Pulse signal during engine rotation
Relay Function Check
After installation, verify each required relay function against the vessel’s approved commissioning procedure. Confirm switching points, delay settings, alarm indications, and associated control circuits before returning the engine to normal service.
Maintenance
Keep the electronics dry and clean, inspect for condensation and corrosion, and check terminal tightness during scheduled maintenance. Factory-set measuring and relay adjustments should not be changed without the applicable system documentation and test procedure.
❓ Common Questions & Answers
Q1: What is the model number?
A: The model is OV72H73-2.
Q2: What is DESPEMES?
A: DESPEMES is a diesel-engine speed measuring system used for engine-speed measurement and relay functions in marine and stationary installations.
Q3: What does C1 represent?
A: C1 is the DC/DC power supply section of the DESPEMES system.
Q4: What does C2 do?
A: C2 is the engine-speed measuring converter that processes the speed-sensor signal.
Q5: What is the C3 section?
A: C3 is the relay section used for speed-controlled automation functions.
Q6: What is C4?
A: C4 is identified with the NTC-related measuring function in this configuration. Exact channels should be checked against the installed system documentation.
Q7: Can this unit be used for a ship main engine?
A: Yes. DESPEMES was designed for diesel-engine applications, including marine engine installations.
Q8: Is this a complete engine control system?
A: No. It is a speed measuring and relay-function system that operates as part of a larger engine instrumentation and automation arrangement.
Q9: Should the relay settings be adjusted after installation?
A: Not unless required by the approved engine documentation or commissioning procedure. Existing settings should be recorded before replacement.
Q10: What should be checked before ordering?
A: Confirm the OV72H73-2 model, card configuration, connectors, supply arrangement, sensor type, and existing engine automation configuration.
⭐ Recommended WARTSILA Models & Spare Parts
For maintenance of Wartsila marine engine automation systems, related spare-part categories include:
- WARTSILA DESPEMES OV72H73-2 – Speed Measuring System
- WARTSILA DESPEMES OV72H73 Rev.2 – Speed Measuring PCB
- WARTSILA DESPEMES C1 – DC/DC Power Supply
- WARTSILA DESPEMES C2 – Engine Speed Measuring Converter
- WARTSILA DESPEMES C3 – Relay Card
- WARTSILA DESPEMES C4 – NTC Measuring Converter
- WARTSILA Engine Speed Sensor – Inductive Speed Pickup
- WARTSILA Turbocharger Speed Sensor – Magnetic Speed Sensor
- WARTSILA Speed Measuring Converter – Engine Instrumentation
- WARTSILA Engine Automation Relay Modules – Speed and Protection Functions
📦 Spare-Parts Recommendation
For vessels operating legacy Wartsila DESPEMES equipment, maintaining a complete spare strategy is useful because the speed measuring system is connected to important engine monitoring and automation functions.
When replacing the OV72H73-2, match the system revision, card arrangement, sensor configuration, supply voltage, and relay settings with the existing installation. The actual unit should be inspected and tested before commissioning on an operational engine.
