VALVE GP-SHUTTLE 2390618 - Caterpillar

This troubleshooting guide is provided as an aid for the serviceman in locating the cause of existing problems. Several possible problems are covered in the guide.Identify the problem from the Problem Index. Then, go directly to the problem in the guide. When you begin the procedure for that problem, start at Step 1 and follow through the step by step sequence. The Steps in solving each problem are arranged in a definite sequence, from the more probable or easiest to check to the less probable or more complex to check. When the cause of the problem is found and corrected, stop the test. Before attempting to analyze transfer switch problems, check any options that might be included with the unit. Refer to TRANSFER SWITCH OPTIONS. Such options will affect the way a transfer switch works and what you thought was a problem may be only one of the options at work.Problem Index
Problem No. 1: "Utility On" Light Will Not Come ON Problem No. 2: No Automatic Startup Or Shutdown Of The Standby Generator Problem No. 3: No Automatic Transfer To STANDBY Power Source Problem No. 4: No Automatic Re-Transfer Back To The NORMAL Source Problem No. 5: On Manual Startup Of Generator With NORMAL Source Voltage Available, Transfer To STANDBY OccursProblems
Problem No. 1: "Utility On" Light Does Not Come On When NORMAL Source Power To Transfer Switch Is Turned ON1: Check for burnt out normal position indicating light on the transfer switch door, and replace if necessary.2: Check switch position-utility light and switch position indicator windows.Test Procedure: Visually check the switch position and the utility on LED on the utility voltage sensor circuit board. The LED should be ON, indicating that (a) NORMAL source power is available to the switch and (b) the LOAD is connected to the NORMAL power supply. If the light is not ON, check Windows A and B on the transfer mechanism. The word "ON" should be visible in Window "A"; the word "OFF" in Window "B". The latter indicates the LOAD is connected to power source "A" (NORMAL source). If necessary, turn OFF all power voltage supplies to the transfer switch and manually actuate the main contacts to their NORMAL source position. With the LOAD connected to the NORMAL power supply and the NORMAL power supply to the switch is turned ON, recheck the switch position-normal position light. The light should be ON.Test Results:A. Switch position-normal position light and circuit board "Utility On" LED are both ON: STOP the test.B. Both Lights are OFF but the standby engine-generator did not start: Go to Problem No. 2.C. Switch position-normal position light is ON but "Utility On" LED is OFF: Go to Step 3.3: Check power supply to utility sensing interface.Test Procedure: With the NORMAL source power supply to the transfer switch turned ON and the switch position-normal position light is ON, use an a-c voltmeter to check voltage at the utility sensing interface terminals N1, N2, and N3. The voltmeter should indicate rated NORMAL