Cummins Alarm PCB Problems

[purchasing-9363]

Good afternoon,

We are struggling with an engine overtemp alarm that is occurring on one of the two 6BT-5.9’s installed on our customers boat.  The alarm is sounding when the starboard engine temp exceeds 174 degrees.  The problem is occurring at the upper and lower helm stations.  The owner had already replaced the PCB’s at each of the two helm stations, with boards marked Cummins/Beede.  The old boards were M&G brand.  We installed a mechanical temperature gauge, in addition to a K-type contact sensor on the engine temp sensor.  All measuring devices were reading within 2 degrees and indicated the alarm is sounding whenever the engine temp rises above 174-176 degrees.  

We purchased a replacement board from Seaboard, based on the website description saying the alarm was supposed to sound when the temp was above 201-203 degrees.  Turns out the board we received was another Cummins/Beede board.  We went ahead and tested anyway.  The results were the same.

So, we’re kind of at a loss at this point.  The gauges at both stations are accurate, yet the alarm sounds 25 degrees below the specified setpoint.  Any suggestions??

Best Regards,

Don Gulliver

Yacht Systems Services, Inc.

Norfolk, VA

Topic

[Tony Athens]

Two things

 

1———Are you using the proper dual station sending unit?  Have you checked  resistance and compared it to the VDO chart on this web site in the instrument diagrams I have posted many times.

 

2————-Send me a clear picture of the PCB board you bought from us that says Cummins- Beede

 

 

[Author]

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