1. Overview

This guide provides step-by-step instructions for replacing FM301.
Since FM301 is connected to 220V AC power, ensure safety precautions are followed.
Refer to the following procedure when replacing the product with a new one.

⚠ Caution: Before starting the replacement process, turn off the BWTS breaker (MCP) at the vessel's Main Switchboard (MSBD).

2. Replacement Steps

Step 1: Close the Valves

1. Locate EV103 (ECU Inlet Valve) under the ECU in the Engine Room and close it.
   
2. Ensure the EV104 (Pneumatic Valve) is also closed.

📌 Why? This prevents seawater from flowing into the system during the replacement.

Step 2: Check Power Disconnection

1. Open the rear cover of FM301.
   
2. Measure voltage at the 220V AC power terminal.
   
3. If the voltage reading is 0V AC, proceed to the next step.
4. If voltage is not 0V AC, recheck whether the MCP breaker is properly turned off.

📌 Why? Ensuring power is off prevents electric shock.

Step 3: Disconnect Wires

1. Mark the position of each wire for easy reassembly.
2. Disconnect all wires of Rear side from FM301.
   

📌 Why? Proper labeling ensures correct reconnection of power and signal wires.

Step 4: Remove and Replace FM301

1. Disconnect grounding wires connected to the ECU piping.
   
2. Remove the old FM301 unit and install the new unit.

⚠ Caution: Be careful not to allow seawater to enter the equipment or cables.

📌 Why? Proper grounding prevents electrical noise and interference.

Step 5: Reassemble in Reverse Order

1. Reconnect all wires according to the marked positions.
2. Close the rear cover of FM301.
3. Open the EV103 valve.
4. Turn on the MCP breaker at the MSBD.
5. Verify FM301 is functioning correctly.

📌 Why? Ensuring all components are restored to their original state prevents operational issues.

3. Summary of Key Actions