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Stephan

Victron BMV 702 - No Power?

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Hello Everyone


I have been using the following system for the past 8 months with no problem at all. Also to mention that I rarely deplete the batteries lower than 85%.

  •     24v 3kw Devel Pure Sine Inverter with a DC charging current of 20-75A.
  •     2x 12v Narada AGM batteries with a charging current limit of 50A.
  •     Battery Blanacer
  •     Victron BMV 702

All of a sudden this morning the Victron monitor went dead? I checked and all the wiring seems to be intact. Any idea what could cause this?

The batteries system still works fine, its just that I do not have any control over the status.


Thank you
Stephan

Narada.pdf

Inverter LPT-manual-EN.pdf

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Sounds like it isn't getting power.

There's a fuse in the red cable that goes from the battery positive to the shunt. Check that fuse.

Also check the RJ-11 cable running from the shunt to the monitor itself.

I don't know the pinout of the cable, otherwise the obvious check is to measure if there is voltage on the cable where it plugs into the back of the monitor.

The system will continue to work because the shunt is just a low-value high-current resistor and that still works as intended.

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Hi Plonkster

Thank you for the quick feedback.
I wanted to check into the issue over the weekend, but then the monitor suddenly started working again, only to sound off a deviation alarm that the one 12v-battery shows 25v and the other 12v-battery shows only 0,04v. I did reset the monitor to factory settings and did also a full setup again, but the deviation is persistent.

I guess there must be a wiring problem?

I'll do a full checkup tomorrow give feedback if I am still in the dark.

Thank you
Stephan

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On 2/19/2018 at 11:42 PM, plonkster said:

That sounds likely.

Hallo Plonkster

Thanx for the reply some time ago. I went through all the wiring, replaced the fuses coming from the battery and everything started working again.

But unfortunately it completely stopped working a week ago. Looking closely I saw that where the com cable plug is going into the shunt, there most probably dripped rain water on it. Because the com cable plug looks blackish as if there was a short of some sort.

I will replace the com cable plug. If that doesn't work I suppose I will have to replace the shunt as the little board on the shunt then probably got damaged.

Would you by any chance know whether it is possible to buy the shunt or the board on the shunt separately?

Thank you

Stephan

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1 hour ago, Stephan said:

Would you by any chance know whether it is possible to buy the shunt or the board on the shunt separately?

You can buy the shunt separately, item code SHU500050100, but by the looks of it this does not include the connection PCB (which is the bit you want). Though these items are usually well protected in conformal coating, so I'd expect that properly cleaning the connector (use some electrical cleaner from an auto-parts place) or maybe getting someone who's handy with a soldering iron to replace the rj-whatever socket (it's a standard part) ought to do it.

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Thank you

Is it possible to buy the RJ12 cable on the powerforum store and if not are there any suggestions where to obtain it?

Regards

Stephan

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The RJ12 (6 pin) can be tough to find in stores which are more likely to stock RJ45 (8 pin) used in the computer world for LAN cables. If you struggle you can order online from http://www.mantech.co.za

Otherwise collect when next in Joburg, they cost about R1 each not sure what they will nail you for delivery!

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On 2018/05/08 at 1:38 PM, Chris Hobson said:

I have some RJ12  sockets in a drawer somewhere and most computer shops will have a RJ45 crimping tool. The tool usually has RJ11/12 dies too.

Hallo Chris

Thanx for the offer. I’m actually also looking for the RJ12 connector since I’m not sure whether the cable connector itself was damaged?

If you have connectors that would be great since “mantech.co.za” (as suggested by Pilotfish) does not have any in store. 

Ps: Is it possible to replace the socket on the pc board of the shunt?

Regards

Stephan

 

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hi @Stephan, i had to make up a cable between the bmv and the shunt as the distance between the pc and batteries was about 15m. the rj12 connectors are scarce and have to be wired correctly. with help from this forum the attached pdf was drawn for the 10m plus wiring setup, hence the three wire combination to prevent power loss over the extra length of the cable.

re the rj12 connectors i got a couple at a shop in cape town [yebo electronics], just phone around in your valley, you'll find them and they are cheap. i got a crimping tool for less than zar140, so if you need to go that way it is not expensive.

regards

g

bmv kabel settings.pdf

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