Bringing Analogue Caterpillar Temp, Pressure and Level Signals onto NMEA 2000 Backbone

[Jeff Evans]

Hopefully folks here can help me out with my project. I have a 1987 Sea Ray 460EC with Caterpillar 3208 engines (375 HP). I have added an Actisense EMU-1 to bring my analogue engine temp, oil pressure and fuel tank levels into my NMEA 2000 backbone.

I now need to characterize the oil, temp and level sensors. The gauges are by Teleflex. I assumed the senders are Teleflex but they are Caterpillar supplied.

Does anyone have the sensor part numbers or even better, the sensor output table so that I can properly scale the output. Any assistance would be great.

Note: Temp gauge range: 120 – 240 F, Pressure gauge range: 0-80 PSI, both are 33 – 240 ohm.

 

[Skybolt]

Jeff this may help you https://clubsearay.com/index.php?threads/actisense-emu-1-engine-converter-analog-to-digital.101609/

But what I did, was start over with new senders that I calibrated and setup first. That thread shows whet I did and how I did it. New sending units from VDO or Faria will have resistance tables that can be entered.

I have to find the Sender part numbers I used, but I have those calibrated custom gauge tables already done. And with Actisense they are in separate files that can be reloaded. So give me a day or two and I can get that info for you. The boat just came out of the water last night so the boat computer is off and the info is on there.

 

[dtfeld]

Welcome to the N2K club. Finding info on the existing senders is tough, I also installed new senders with known data curves. Other option is to calibrate on them at home which is the old school method.

Of course now you’ll want to add boost, EGT, instrument the gears and get the fuel senders on the network!

 

[Skybolt]

Welcome to the N2K club. Finding info on the existing senders is tough, I also installed new senders with known data curves. Other option is to calibrate on them at home which is the old school method.

All the senders available from VDO and Faria publish the resistance curves for there senders which makes it super easy to just enter that data.

Not sure what the new school method of calibrating is, since you think at home is old school method? Calibrating at home just makes it much easier then climbing around an engine while it's hot to get readings.

 

[kvduff]

Following

 

[dtfeld]

All the senders available from VDO and Faria publish the resistance curves for there senders which makes it super easy to just enter that data.

Not sure what the new school method of calibrating is, since you think at home is old school method? Calibrating at home just makes it much easier then climbing around an engine while it's hot to get readings.

Old school would be dunking temp senders in water and plotting temp vs resistance. I’m pretty sure this is how Tom did the early conversion. Prefer published tables if available, or how Chetco did it with setup files.

Bottom line it ain’t easy.

 

[Skybolt]

Old school would be dunking temp senders in water and plotting temp vs resistance….prefer published tables.

I did both on the EMU's. I found the boiling water to be more accurate. I then used those resistance readings for the curve entry.

 

[Skybolt]

@Jeff Evans Jeff I posted the temp and oil pres files at the end of this thread - https://clubsearay.com/index.php?threads/actisense-emu-1-engine-converter-analog-to-digital.101609/