The Wartsila C1 DC/DC 110V Relay Card, identified by part number 007370037, is a high-reliability power management and switching module designed for marine engine control systems and industrial power plants. As a core component of the Wartsila UNIC (Unified Controls) and C1/C2 automation architectures, this card performs dual roles: it provides stabilized DC/DC voltage conversion to power sensitive logic circuits and serves as a heavy-duty relay interface for field actuators, solenoids, and alarm systems.

1. Technical Parameters & Datasheet

The 007370037 is engineered to withstand the extreme vibration, thermal fluctuations, and electrical noise characteristic of a ship’s engine room. It acts as a ruggedized buffer between the high-power DC bus and the low-power control electronics.

Hardware and Design Features

• Integrated Power Conversion: The card eliminates the need for external converters by stepping down the 110V DC shipboard power directly to the 24V DC required for internal control modules.
• Dual-Layer Protection: Each relay output is equipped with snubber circuits to suppress back-EMF (electromotive force) generated by inductive loads like fuel racks or cooling pumps.
• Diagnostic Feedback: Every relay channel features a high-visibility LED indicator. Furthermore, the card transmits a “Health Status” signal to the main engine controller, alerting operators to fuse failures or voltage drops.
• Vibration Resistance: The PCB is treated with a specialized conformal coating and utilizes reinforced solder points to prevent mechanical failure during the high-frequency vibration common in four-stroke and two-stroke marine engines.

 

2. Country of Origin

The Wartsila C1 DC/DC 110V Relay Card (007370037) is primarily manufactured in Finland. Wartsila’s automation centers in Vaasa, Finland, oversee the engineering and production of the UNIC system components. Certain manufacturing batches may also originate from specialized marine electronics facilities in Norway or Switzerland under Wartsila’s global quality standards.

 

3. Product Related News (2025-2026)

Lifecycle Support Expansion

In early 2025, Wartsila announced an extension of its “Service Life Support” program for the C1 automation series. This is significant for vessel owners operating ships built between 2005 and 2015. The 007370037 card has been designated as a “Long-Term Availability” part, ensuring that spare units will remain in production through 2035 to support the existing global fleet.

Efficiency and Thermal Management Research

Reports from Wartsila’s 2026 maritime R&D symposium highlighted that recent revisions of the 007370037 (Rev. E and higher) utilize high-efficiency planar transformers. This change reduces heat dissipation by 15% compared to legacy cards. This improvement is critical for engine control cabinets that are often located in high-ambient-temperature zones near the exhaust manifold.

Decarbonization and Fuel Flexibility

With Wartsila’s 2026 push toward “Future-Fuel Ready” engines (Ammonia and Methanol conversions), the 007370037 Relay Card has been re-certified for use in gas-safe control systems. Its high galvanic isolation makes it suitable for the intrinsically safe barriers required when managing alternative fuels with lower flashpoints.

 

4. Application Areas

The 007370037 is a critical interface for several engine-side functions:

• Engine Safety System (ESS): Driving the emergency shutdown (ESD) solenoids when a critical overspeed or low oil pressure event is detected.
• Power Management Systems (PMS): Managing the start/stop sequences of auxiliary generators in a 110V DC shipboard network.
• Fuel Injection Control: Providing the power and switching logic for the heavy-duty actuators used in common-rail fuel systems.
• Lubrication and Cooling: Controlling the electrical pre-lubrication pumps and thermostatic valves that maintain engine temperature during standby.

 

5. Usage and Installation Instructions

Installation Procedures

1. Safety First: Ensure the 110V DC power source is locked out. High-voltage DC can cause severe arcing if the card is inserted or removed under load.
2. Mounting: Align the card with the slots in the Wartsila UNIC module carrier. Ensure the multi-pin connector is fully seated before tightening the front-panel retaining screws.
3. Jumper Configuration: Depending on the specific engine model (e.g., W32, W34, or W46), certain jumpers on the card may need to be positioned to define relay logic (Normally Open vs. Normally Closed).

Wiring and Connectivity

• DC Input: Observe strict polarity when connecting the 110V DC input. While the card has reverse polarity protection, prolonged incorrect wiring can trip upstream breakers.
• Relay Outputs: Use ferrules on all multi-strand wires. Ensure that the maximum current per channel (8A) is not exceeded to prevent carbon buildup on the relay contacts.

Maintenance

• Contact Testing: During dry-docking or annual inspections, perform a manual relay test via the automation interface to ensure no contacts are “stuck” due to age or environmental exposure.
• Visual Inspection: Check for any signs of “browning” on the PCB, which indicates localized overheating, often caused by poor terminal connections or overloaded circuits.

 

6. Recommended Related Wartsila Models

If you are maintaining or designing a system utilizing the 007370037, the following Wartsila components are often used in the same control loop:

• Wartsila 007370038 (C1 DC/DC 24V): The 24V input variant used in ships with standard low-voltage DC networks.
• Wartsila 004740001 (UNIC Main Controller): The central processing unit that sends the command signals to the relay card.
• Wartsila 006470005 (Analog Input Card): Used to monitor engine temperatures and pressures, feeding data that triggers the 007370037 relays.
• Wartsila 008450012 (Power Supply Unit): A centralized power module often used to feed the 110V DC bus.
• Wartsila Speed Sensor (Magnetic Pickup): Provides the engine speed frequency that the safety system uses to determine when to trigger the ESD relay on the card.