Change Wiring To Prevent Low Oil Pressure Shutdown Immediately After Start-Up
3208, 3300, 3400 and 3500 Families Of Generator Sets Equipped With Floor Standing Switchgear or 4W8000 Control Panel With Automatic Start/Stop Module
Some of the above generator sets have experienced shutdowns during acceleration, immediately after start-up. This problem is more likely to occur when the engine has not been operated for ten hours and/or the engine oil is cold.
The negative terminal, Terminal (3) of the Time Delay Relay (TD) shown in the illustration, is normally connected to the positive side of the pinion solenoid. This is necessary to allow instant restart when the earlier 3N8900 Panel is used. This connection will conduct electrical noise to the Arming Delay Timer (ADT) used in the floor standing switchgear or the 4W8000 Control Panel. This can result in an occasional low oil pressure shutdown during start-up. An ADT is not used in the 3N8900 Panel.
If the generator set has a floor standing switchgear or a 4W8000 Control Panel with an Automatic Start/Stop Module, the negative terminal of the Time Delay Relay [Terminal (3)] should be connected to the battery negative or Terminal (28) in the engine mounted junction box.
If the above problem is experienced on generator sets with either a floor standing switchgear or a 4W8000 Control Panel with an Automatic Start/Stop Module, make the following wiring change in the engine mounted junction box. After making these changes, it will still be possible to restart the engine immediately after a shutdown.
1. Locate Terminal (27) and Wire (TS27-TD3) that goes between Terminal (27) and Terminal (3) of the Time Delay Relay (TD).
2. Disconnect Wire (TS27-TD3) From Terminal (27).
3. Connect Wire (TS27-TD3) to Terminal (28).
There have also been cases where the ADT (used in the Automatic Start/Stop Module in the 4W8000 Control Panel) was not adjusted correctly at the factory. This can result in occasional low oil pressure shutdowns. This usually occurs when the engine has not been operated for ten hours. If this problem is experienced on a generator set with a 4W8000 Control Panel with the Automatic Start/Stop Module, check the ADT adjustment as follows.
The ADT should be set for a ten second delay, to prevent the low oil pressure shutdown from functioning until the engine oil pressure builds to operating range. Refer to Service Manual, Control Panel (SR Generator Mounted), form SENR4027, Page 33.
The ADT adjustment can be checked by placing a DC voltmeter on Terminals (A+ and B-) of the Arming Relay (AR). During start-up, the voltmeter should read zero for ten seconds. After ten seconds, the AR will arm the oil pressure shutoff system. Adjust the ADT as necessary to obtain the ten second delay (near the blue dot on the timer). The ADT and the (AR) are located in the Automatic Start/Stop Module. See Service Manual, Control Panel (SR-4 Generator Mounted), Form SENR4027, Page 12.
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