Wire break surveillance on a generator set

Thread Starter

StrongPenguin

Joined Jun 9, 2018
267
Greetings.

We have this issue with our (maritime) genset. We get alarms for "Break wire", but we haven't yet had the opportunity on fault finding yet.

The box below the P3.02 pressure stat is the PLC. We have a suspicion about one of the surveillance resistors, as we have seen this before. Now I would like hear what the actual function of this is.

If the engine is running as normal, the lube oil pressure is above 0.8 bar, and the switch is not activated, but the R3.03 resistor still keeps a current path open. Is this then considered in high impedance mode, since the resistor is 18k Ohm, thus allowing wire monitoring?

This circuit is all the information I have. I have the whole diagram, but the rest has nothing to do with this issue.

Bonus question: What is the puprose of R3.08 and .07?
 

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DNA Robotics

Joined Jun 13, 2014
599
R3.08 and .07 may be so they can use a 12 volt relay on a 24 volt system.

If that is on a systems monitor like Hatteras uses, I would suspect the systems monitor relays causing intermittent alarms.
 

Thread Starter

StrongPenguin

Joined Jun 9, 2018
267
It looks as if we found the issue, or at least resolved it. We measured all the resistors (which were ok) and in the process fixed problem.
 
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