KONGSBERG SR/SV Steering Servo Maintenance Comprehensive Guide

7.7 Internal Leakage Test - Variable Frequency Pump

Purpose: To evaluate the internal sealing of pumps and valve assemblies.

Prerequisite: When the vessel is stationary in sheltered waters, it shall be executed by the chief engineer. Pump 1 and pump 2 need to be tested separately.

Steps:

Close the valve from the leaking oil pipe to the expansion tank.

Remove the leaking oil pipe from the top of the actuator and connect the drainage pipe to the measuring bucket.

In the motor control cabinet, select "local control" for the pump to be tested and "stop" for the other pump.

Use the emergency steering button to operate the servo from 30 ° on one side to 30 ° on the other side, record the time, collected oil volume, pressure, and oil temperature.

Test completed, restore the pipeline and open the valve.

Result: Record in the feedback form. If any abnormalities are found, send them to Kongsberg.

7.8 Steering Time Test - Variable Frequency Pump

Purpose: To confirm the health condition of the internal seal of the servo motor.

Steps:

Ensure that all valves in the expansion tank are open.

Set the pump to local control and stop the other pump.

The operation of the servo starts at approximately 33 ° on one side, and the timing starts when the rudder blades pass 30 °. The timing stops when they reach 30 ° on the other side.

Test two directions and two pumps separately.

Result: Record the time of tests # 1 and # 2.

7.9 Feedback Form

The manual provides a standardized feedback form for recording the results of leak testing and steering time testing, including oil level, time, pressure, temperature, etc., and requires them to be sent to a designated email address.

7.10-7.11 Testing of Conventional Pump Systems

For conventional pump systems, the testing logic is similar but the operational details are different.

Leakage test: Close the ball valve of the return oil pipe and introduce the return oil into the measuring bucket. By using solenoid valve emergency control, operate the servo from one side limit to the other side limit, and stop at the limit to measure the oil collection amount within 1 minute.

Steering time test: measure the time required to travel from 30 ° on one side to 35 ° on the other side.

7.12 Visual inspection

Limit switch: Check if the fastening screw on the cam is tightened, manually turn the switch to confirm the function of the spring and contacts.

Electromagnetic valve coil: Check whether the connecting plug has water or moisture to prevent grounding or short circuit.

Feedback potentiometer: Check if the fastening screw that fixes the potentiometer shaft is secure and if the circuit is loose.

7.13 Emergency steering test

Before operation, be sure to notify the driver's console and maintain wireless communication. Turn the selection switches of the two motor controllers to "local control" and operate them using the emergency steering button on the cabinet. After the test is completed, reset the switch to "remote control".

7.14 Alarm System Function Test

The manual provides a detailed list of simulation testing methods for various types of alarms (note that there is a 5-second delay for alarms, and one alarm needs to be cleared before testing the next):

Overload alarm: FCP system disconnects overload contact; Press the overload relay test button on the PU system. The standby pump should be started.

Phase loss alarm: Remove one fuse. The standby pump should be started.

Power/frequency failure: Turn off the main switch. The standby pump should be started.

Power control failure: Turn the selection switch to local or stop. The standby pump should be started.

Low oil level alarm: Disconnect the connector plug on the expansion tank. The standby pump should be started.

Hydraulic lock alarm: FCP system disconnects X1-2 in the junction box; The PU system manually activates the solenoid valve for more than 5 seconds. The standby pump should be started.

Isolation valve fault alarm (FCP only): Disconnect the solenoid valve plug of the corresponding pump, the pump should stop, and the backup pump should start automatically.

Auxiliary alarm: Disconnect the feedback line of U10 module in the control system, and the alarm should be triggered after 5 seconds (DP2 level and above ships will also trigger "rudder freeze").

7.15 Grounding Inspection

Power on inspection: Use a voltmeter to measure the voltage between the grounding terminal of the component and the hull. A reading above 0V may indicate the presence of abnormal voltage or induced current, posing a risk of electric shock and requiring investigation by an electrician.

Power off inspection: Measure the grounding resistance with an ohmmeter.

7.16 System temperature check

It is recommended to use an infrared thermometer to check the temperature of the pump, valve block, housing, and expansion cabinet to ensure no sudden changes. The maximum ambient temperature is 45 ° C, and it is recommended that the short-term peak value of the system should not exceed 70-80 ° C. If the system remains below 10-20 ° C for a long time, the ambient temperature should be increased or low viscosity oil should be replaced.