It seems that there is no connection between remote start signal and paradox, so why put them together? Read on, the answer will come out.
Let’s introduce “Fault Symptom” first: customer gives feedback that all three units in three different locations fail to start remotely.
NO.1
Fault symptom: Customer said that after the first remote auto start failure, and manual alarm was reset, the second time whether manual or auto start, genset could operate normally.
Fault reason analysis: This is an 900kW ECU unit, and due to the large engine, it is equipped with an electric pre-supply pump to supply fuel to the system before starting the engine, so as to ensure the necessary lubrication of each friction interface during the crank process. The required pre-supply time is 30s, and the oil pressure should reach 150kPa when engine ECU detects crank. But the (pre-heat time) pre-supply time set by controller is only 2s. Therefore, oil pressure is difficult to reach 150kPa when engine is cold starting. ECU issues oil pressure low shutdown alarm and unit failed to crank.
Solution: Set (pre-heat time) pre-supply time as 30s by controller and change controller crank disconnect condition from “frequency + oil pressure” to “frequency + speed”. The positive pole of ECU main power and ignition switch signal line are connected in parallel to controller’s FUEL output, and fuel output time is set to 5s. After the above parameter setting is finished and remote start signal is active, unit cranks success.
NO.2
Fault symptom: Customer said that genset couldn’t start automatically when mains power off.
Fault reason analysis: Under normal operation, the unit will start automatically after the remote start input port of the controller is linked to close by external closed contacts. Reasons for not start automatically: 1. Problem of remote start signal; 2. Problem of Controller.
Fault finding:
1.Set controller in auto mode, and make remote start input port and common ground short connected with wire, controller start automatically. Controller problem is excluded.
2.In this case, the normally closed contacts of external AC220V relay is used as remote start signal to output. When mains signal is disconnected, relay normally closed contacts do not close and relay function is abnormal.
Solution: After replacing AC220V relay, remote start signal recovers normal and problem is solved.
NO.3
Fault symptom: Customer said that genset always failed to crank whether manual or auto start, controller issued low oil pressure shutdown.
Fault reason analysis: If low oil pressure shutdown occurs frequently during cranking, It is speculated that the engine may not really start successfully, and the oil pressure may be selected under the successful starting conditions. Oil pressure is often low and unstable during cranking, especially in winter.
Fault finding: Open controller parameter setting and view selection of crank disconnect conditions. You can see that customer chooses “frequency + oil pressure”, and controller’s speed signal sampling does not connect to speed sensor.
Solution: Change the crank disconnect conditions to “speed + frequency”, make speed signal paralleled to speed sampling of GOV board (speed sampling of GOV board is connected to speed sensor). When remote start signal is active, auto start is normal; start the unit manually, unit cranks normally.
The solutions of above 3 cases are involved the root cause. Seeing the symptom through the essence perfectly explains the “paradox” of the title.
Summary: For situation similar to remote start, unit crank failure, it appears to be unit crank failure, but in fact this fault is caused by various reasons, which are summarized in the following table. We hope these cases can help you to deal with similar problems accurately and quickly.
Troubleshooting Table of Remote Start Failure
