Actisense EMU-1 Engine Monitor and AC Delco Guage info

[MVCaprice]

Does anyone have guage info/curves for the dual station AC Delco gauges/senders? I have been working with ActiSense on getting support for our gauges and need a few more pieces of info.

I previously cataloged the following on my (12v) gauges:


Water Temp 100-220 Degrees F
Duel Station Guage
AC Delco Part Number 8993271
Ground to Postive Resistance in Ohms 201.3
Positive to Sender Resistance in Ohms 47.7
Ground to Sender Resistance in Ohms 248.8

Drive oil Pressure 0-400PSI
AC Delco Part Number 25025326
Ground to Postive Resistance in Ohms 191.1
Positive to Sender Resistance in Ohms 118.7
Ground to Sender Resistance in Ohms 75

Oil Pressure 0-80PSI
Duel Station Guage
AC Delco Part 5626324
Ground to Postive Resistance in Ohms 217.2
Positive to Sender Resistance in Ohms 118.5
Ground to Sender Resistance in Ohms 98.9

Below are the data points that ActiSense is asking me for currently. I have only completed step one unfortunately.

Procedure for manually measuring a gauge

[FONT=Calibri,Calibri][FONT=Calibri,Calibri]Equipment required: A Multimeter with Voltage, Current and Resistance measurement.
The test consists of 2 steps, the first step measures the gauge when it is completely disconnected from everything. The second step measures the gauge when it is connected to its normal power supply on the boat.


[/FONT][/FONT]Step 1
[FONT=Calibri,Calibri][FONT=Calibri,Calibri]Disconnect the gauge from everything. The gauge should have 3 terminals:
1. + terminal (The supply voltage terminal)
2. – terminal (The ground terminal)
3. S terminal (The Signal terminal which connects to the Sender)
Test 1, Using the multimeter set to ‘Resistance’ measurement mode
1. Measure and record the resistance between the + terminal and the – terminal.
2. Measure and record the resistance between the S terminal and the – terminal.
3. Measure and record the resistance between the S terminal and the + terminal.


[/FONT][/FONT]Step 2
[FONT=Calibri,Calibri][FONT=Calibri,Calibri]Now connect the gauge to its normal power supply. Connect the – terminal to ground and the + terminal to the normal supply voltage, NB - leave the S terminal unconnected, it must not be connected to the sender!
Test 2, using the multimeter set to ‘Voltage’ measurement mode
1. Note down whether the gauge needle deflects to full scale or whether it stays at zero.
2. Measure and record the exact supply voltage between the + and - gauge terminals.
3. Measure and record the exact voltage between the S and – gauge terminals.
4. Start the motor and let it idle, again measure and record the exact supply voltage between the + and - gauge terminals.
5. Start the motor and let it idle, again measure and record the exact voltage between the S and – gauge terminals.
Test 3, using the multimeter set to ‘Current’ measurement mode (leads inserted into current measurement terminals on multimeter)
1. Measure and record the current between the S and – gauge terminals. (Red lead connected to S terminal, Black lead connected to – terminal)
2. Note down whether the gauge needle deflects to full scale or whether it stays at zero.

[/FONT][/FONT]

 

[MVCaprice]

Update: Actisense recently released firmware for the EMU-1 to allow arbitrary calibrations. This may be very helpful for those of you who want to do NEMA 2000 gauges.


https://desk.zoho.eu/portal/actisense/kb/articles/emu-1-custom-gauge-tool

 

[MVCaprice]

One other cool thing worth mentioning regarding NEMA 2000 gauges....

After swapping the Northern Lights 6 wire pigtail to a 8 wire pigtail and readding in the stock senders which were removed in liu of mechanicals I was able to get the Actisense EMU-1 working quite well with the Northern Lights. I ended up installing an engine room temp sender from Yacht Devices as well and am now displaying them all through a Garmin GMI-20 marine instrument.

 

[Photolomy]

Thanks for the info. I want to use NEMA, but not necessarily replace my analog gauges. I saw a Nordhavn that captured the stats (temp, oil, etc.) to a server every 10 seconds so that they could be reviewed periodically for trends, pointing to potential growing issues.

 

[drburke]

Thanks for images! Looks great.

[I mistakenly responded to quite an old post when it was bumped--sorry for boneheadedness]

Don't be too intimidated by their request.

Basically they are just checking a few things:
-whether increasing pressure raises or lowers voltage (almost always does)
-no hidden resistors to limit range (can calculate that current, but making sure)
-what the actual voltage on the meter is (a little higher with alternator on)
-verifying not a current-type of transducer or detection

Your first value needs correcting: 248.8 ohms is the total from positive to negative, BTW; ground to sender will be the 201 ohms value.

Can go into more detail if you want...

DAN

 

[MVCaprice]

Thanks for images! Looks great.

Don't be too intimidated by their request.

Basically they are just checking a few things:
-whether increasing pressure raises or lowers voltage (almost always does)
-no hidden resistors to limit range (can calculate that current, but making sure)
-what the actual voltage on the meter is (a little higher with alternator on)
-verifying not a current-type of transducer or detection

Your first value needs correcting: 248.8 ohms is the total from positive to negative, BTW; ground to sender will be the 201 ohms value.

Can go into more detail if you want...

DAN

Thanks for the feedback. It has been a long road but I am very close.

I ended up using a Noland MD33 on the mains to deal with the older senders. I have them just about as dialed as they can be. Unfortunately the MD33 has linear gauge curves and is not super accurate. I have dialed almost everything in with the exception of the coolant senders. I need to spend a bit more time on that to get it dialed.

On the other hand the VDO senders I have been using in conjunction with the Antisense are spot on and super accurate. I am fairly impressed with that device.