Electric Current Meter on SO36i

[Trevor]

I hope this may help someone who would like this function working on their Jeanneau. The electronic metering hardware is already a part of the multifunction panel on the 36i so all it needs is a shunt to make it work.

In a previous thread I have bemoaned the embarrassment suffered through not being able to get the current meter working on the electrical panel on my SO 36i. I knew the same French multipurpose panel was used on larger yachts that come with the ammeter function. How hard could it be?

I purchased a 50mV/100Amp shunt and installed it. I then took the sensing wires to the input of the multipurpose panel. Guess what?.......it didn't work.

This had me really checking the wiring and ensuring that I hadn't made any silly mistakes.

Then came the Sydney boat show. I climbed aboard an SO45 that had the ammeter function. On this vessel you can gain access to the back of the electrical panel without a screwdriver! I learned that the shunt has to be wired on the negative return to the battery and not on the positive side as I had installed mine.

Today I installed the shunt on the negative side and it works like a charm. ;D





The photos reveal the location of the shunt above the connector panel and how the main connection back to the battery now goes through the shunt. Simply lift the thick black cable off the termination bolt and fix it to one side of the shunt. Take a short cable from the other side of the shunt and connect it to the termination bolt on the top of the connector panel. The second photo shows the sensor wires going into the connector on the multifunction panel. The black sheathed cable is the sensing cable. The third photo shows the indicator panel with the current indication in Amps located at the top right corner.

This is a really inexpensive and easy way to give an indication of how much current is being used by your electrical devices if you own an SO36i or any yacht with this type of multifunction electrical monitoring panel. It satisfies my need to know what is being drawn from the house battery. It is good to know how much current each device uses and what the total load is.

Happy to answer any questions if required. ;D

Regards,

Trevor

[jamestown]

This is very informative. I have the 39i. Can I assume that the display on my boat is capable of this function? The display looks the same as the one on your boat.

Also one question. I don't quite follow what the second black wire on the original terminal is... but perhaps when I get out to the boat it will be clear.

Thank you.

[Trevor]

Hi Jamestown,

Yes, this is the same electrical panel as the 39i. The second black wire on the original terminal I think from memory goes to another distribution fuse holder and distribution panel below the one in the photo so the current through the shunt does accurately reflect the entire current through all loads.

Good luck, it is well worth the effort as most of the infrastructure is already there. ;D ;D

Trevor

[jamestown]

Thanks so much. This is brilliant. One small question: Did the sensor wire come with the shunt or did you have to make it up? What brand and model shunt did you buy?

Steve McInnis

[jamestown]

Also, Trevor, does it matter it the output is 50,75 or 100mV? Will that just affect the sensitivity or do you have to match it to the meter to get the correct result?

Steve

[Trevor]

Hi Jamestown,

The sensor wires have to be made up as they do not come with the shunt but they are simply a couple of wires. They don't have to be anything special.

It is important to get the right specification shunt. I am not sure of the brand I used (and that is not important) but it is important that the shunt is a 100 amp, 50mV type. That simply means that if 100 amps flows through the shunt, 50 millivolts will be developed across it. If you use another rating shunt the current meter will not be accurate. For instance if you use a 100amp/100mV shunt the current meter will display twice what the actual current really is.

I hope this helps,

Good luck,

Trevor

[jamestown]

Thanks. The one I ordered is 150A 50mV. If I understand it correctly this will show the proper amperage since the output is 50mV. Do you agree? I looked on my boat and I see that two of the holes in the meter connector are marked "shunt +" and "shunt -". I assume I will just experiment to see which wire from the shunt will be for the + and which for the -, or the current will read as discharging when charging and charging when discharging. Or doesn't the meter read the direction? This is very useful. I will get a few different size ends for the sense wire to go into the meter connector. They seem to be very small tubular connectors.......

Steve

[jamestown]

Trevor:

I think I answered my own question. I called Deltec, the manufacturer here in the States of shunts. I did buy the incorrect one, based on your statement that the ratio the meter needs is 100/50. However, I don't want to use a 100a shunt because I upgraded my alternator and sometimes it charges at more than 100 amps, plus when I run my microwave through the inverter it draws at least 100 A (although just for a short period). So the Deltec guy said the ratio is what counts, so that I should use a 200A/100mv shunt which generates current at the same ratio as the 100A/50mv shunt, but can physically handle the extra current. So I've ordered one of them. Thanks again for this great idea!!!

Steve

[Trevor]

Hi Jamestown,

That sound right to me regarding the size of the shunt. The 200amp/100mv will provide accurate current readings. If you are genuinely drawing more than 100 amps you may consider increasing the cross sectional area of the positive and negative cables coming from the battery. Just a thought.

The +ve sense wire goes to the side of the shunt connected to the bolt on the top of the distribution panel. The -ve sense wire goes to the side of the shunt connected to the battery.

The current meter in this configuration will not show you the charging current from the alternator. It is only able to show you the load through the distribution panel, not the charge current from the alternator.

I hope this helps,

Trevor

[jamestown]

thanks again Trevor. Your info is most informative. You should also know that when one sends an email to Jeanneau asking about this topic they cut and paste your posts to this forum as an answer..

I will report in when I install the shunt. I have a handheld amp meter so I can doublecheck the results.

Steve

[MalcolmP]

Oct 7, 2008 15:15:26 GMT jamestown said:

You should also know that when one sends an email to Jeanneau asking about this topic they cut and paste your posts to this forum as an answer..

I suppose it maybe reassuring that big brother J is watching this space or maybe not

Malcolm

[jamestown]

Trevor, I followed your instructions, using a 200A, 100mv shunt and voila, it works!!! My only problem is finding the correct little connectors for the sense wire going into the wire block for the meter. I bought a couple at Radio Shack but nothing really fit so I just temporarily jammed the sense wires in, so they connect OK to show the reading. Do you have any info as to what exact connector I have to buy and where I might get it? I know you are in AU, but maybe somewhere online? thanks for this brilliant idea.

Steve

[Trevor]

Hello Jamestown,

You've found me out!!!! I had to jam the wires in because I haven't been able to find those connectors yet either.

Hopefully I will get motivated and find the correct connectors sometime.

I'm really glad it worked for you,

Regards,

Trevor

[jamestown]

Ha that's funny. I even tried destroying some little connectors but no go. Let me know if you find something.

Steve

[sailingpages]

Hi,

Although I'm yet to actually do the modification, I believe I have found the correct socket contacts to suit the MATE-N-LOK connector on the back of the digital panel (for shunt sense connection). This connector is a Universal MATE-N-LOK Connector manufactured by Tyco Electronics. Although I haven't tried them out yet, I have bought two types of socket contacts to suit the connector. What I bought are Tyco# 350550-2 (Farnell Electronics Part # 1825355) and Tyco# 350551-2 (Farnell Electronics Part # 1169962). The two different types of contacts are to suit different insulation diameters. Each of these contacts suit wires AWG 20 - 14.

I can't guarantee that this correct at this stage because I'm yet to install them but I'm reasonably confident. Once I do the mod, I'll know for sure.

Cheers,
Geoff.

[Trevor]

Nice work Geoff,

Let's know when you have confirmed they are the correct connectors and I will procure them and finally really finish that installation! ;D ;D ;D

Many thanks,

Trevor

[sailingpages]

Hi Trevor and all,

Yes, the connector contacts that I mentioned in an earlier post are correct for the MATE-N-LOK connector (Tyco Electronics) used on the back of the digital panel (for shunt sense connection).

I had bought two types of socket contacts to try to suit the connector, Tyco# 350550-2 (Farnell Electronics Part # 1825355) and Tyco# 350551-2 (Farnell Electronics Part # 1169962). The two different types of contacts are to suit different insulation diameters of 1.52 - 3.30 mm OR 3.30 - 5.08 mm diameter respectively. Either of these contacts will suit wires AWG 20 - 14.

I used ~ 1.5 mm^2 (AWG 16) wire for the shunt sense wires from the shunt to the MATE-N-LOK connector, I ended up using the Tyco# 350550-2 (Farnell Electronics Part # 1825355) contacts to suit the insulation diameter of the wire I used. I crimped and then soldered the wires to these contacts before I inserted them into the back of the connector housing. Caution though, don't insert the contacts into the MATE-N-LOK housing until terminated to the wires as it may be tricky to extract them again.




Cheers,
Geoff.

[Trevor]

Nice work Geoff and thanks for the information. ;D

I am on the case and will install them when I get them.

Regards,

Trevor

[Trevor]

Hi Geoff,

Ordered the connectors you described on the Internet from Farnell. They arrived and are now installed. ;D ;D ;D

Many thanks.

Trev

[sailingpages]

Hi Trevor,

Glad to help out. Thanks again for your original investigation and solution for the current meter.

Cheers,
Geoff.

[jamestown]

I installed the correct wire connections for the panel wire block per the suggestions on this thread. It worked great and is now a professional job!! Thanks Trevor for this very very useful post.

Steve
Newport, RI
Alegria 39i

[cliveshelton]

Thanks for finding the connectors (whoever that was). I installed the shunt today with only partial success. The ammeter shows up when one of the black battery leads is connected. The volt meter show 9v and the ammeter 100A. Also a little exclamation mark shows. Once the other black lead is connected as described by the OP the ammeter disappears and voltage show 14.1 V. I wonder if anyone can tell what I am doing wrong. Thanks.

[cliveshelton]

I've just thought......I had shore power on and the battery charger on. I wonder if that wud affect the setup?

[rene460]

Hi Clive,
You have come in on an old topic for which most of the original contributors have not logged in for some time, but here are some thoughts that may help with your problem.
The 100 A plus a ! are the overload indication indicating that you have more than the expected 50 mV across the shunt (0.05 V).
The shunt is an accurately made very low value resistor which goes between the negative lead to the battery and the NEGATIVE common terminal block for all the consumers. The ammeter is actually allow range volt meter typically and likely 0.2 V full scale and calibrated in Amps. Ohms law says the resistance of the shunt is only 0.0005 ohms (yes, 0.05 V/100A ) which provides the current calibration factor. The instrument has two wires, one to the battery side of the shunt and a sensing wire connected to the user side of the shunt. There should be no red leads anywhere near the shunt and certainly no voltages like 12 V.
I would assume the volt meter picks up its positive lead within the panel.
Rene460

[j]

Nov 17, 2012 23:05:26 GMT cliveshelton said:

. Once the other black lead is connected as described by the OP the ammeter disappears and voltage show 14.1 V. I wonder if anyone can tell what I am doing wrong. Thanks.

silly question, but did you have anything switched on (at the switch panel) that would be drawing 1 amp?