question

mfred68 avatar image
mfred68 asked

Lynx shunt failed twice now

My original linx shunt 1000 failed after a couple of weeks of use, the communication completely stopped and it no longer showd up in my device list, apart from saying "last seen"

I returned it to the seller, and they tested it and indeed it wasn't working with them either, so they sent me a replacement.

I fitted the replacement and connected it to my cerbo gx, and it showed up on my victron app, so I was able to go to it's settings and set up all the parameters.

Then the next day I went to check it's readings and I had the message "last seen 9 hours ago" and the shunt was off line. The orange light was blinking on the shunt, which means firmware issue, so I tried to update the firmware, but because the shunt is showing as off line, I can't update it. I rebooted the whole system by turning off the power but that also made no difference.

I reported this problem to the seller, but now they are more defensive saying it has never happened before that two shunts go faulty after another and blaming my wiring. But my wiring is perfectly OK. So what could be causing 2 shunts to fail? The only thing in common is the cerbo gx, but that appears to be working fine so not sure what's going on.

How can I update its firmware, being it's no longer seen by the cerbo gx?

I don't want to end up with simply an expensive fuse holder!

lynx shunt
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3 Answers
Alexandra avatar image
Alexandra answered ·

@mfred68

If it is being killed over Comms then it is usually related to an isolation/grounding issue.

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mfred68 avatar image mfred68 commented ·

That's interesting, but can you please explain what would cause an isolation grounding issue? The cerbo power leads are connected directly to the lynx distributor, so there should be no isolation between the two units in the power lines.

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Alexandra avatar image Alexandra ♦ mfred68 commented ·

Since I know nothing about the install specifics are difficult.

Do you have the can terminator in?

What cat cable was used between the system and the cerbo? Does the cerbo have isolated or non isolated ports for can. (Newer models have a different spec.) Since this is the second fail, are you sure there are no issues with the distributor, since they are linked?

Have you run comms cables near power cables?

Have you grounded the lynx system at all? Or the batteries to the lynx system?

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mfred68 avatar image mfred68 Alexandra ♦ commented ·
I have used terminators and I have used straight rj45 cables (no crossed wires) the comms cable for the shunt is not yet fixed into place as the system is still under construction, but it does pass 90 degrees past the 70mm inverter cables by which is just a few cm's so this shouldn't cause any induction being it's dc.

When you say "grounded" do you mean earthed? The answer is yes, everything metal is earthed including batteries inverter mppts etc.

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dwmarine avatar image
dwmarine answered ·

As per Alexandra's comment, there have been instances of Victron equipment being damaged because the communication cables have been connected before the main negative wires, or disconnected after the main negative wires.

This puts all the main negative voltage/ current through the data cable negative.

The data cable does not have an isolated ground on some equipment.

Pretty sure here is a way to manually force on the Lynx shunt via blue-tooth in the manual.

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mfred68 avatar image
mfred68 answered ·

I'm this case every was powered on after all the connections were made. Also the first shunt was working for about a month before it lost coms, so they sent me a replacement, and that shunt also worked but only about 10 hours before failing too.

It's got to be the cerbo corrupting it? Although the system is working perfectly otherwise.

So if the orange light flashes and the shunt is off line, does that mean the hardware needs replacing or can the firmware be installed again a different way?

This shunt is only ve can, there is no Bluetooth or ve direct

I've tried several rj45 straight cables and have the terminators in the empty ports.

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Related Resources

Lynx Shunt VE Can online manual


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