Hi All,
Wondering if anyone has split their Lynx modules by using cables to extend the bus bars. I do not have space in my boat to bolt the power in, bms, and distributor together. Instead I would like to have the power in and bms bolted together and use 4/0 cable to connect to the bus bars of the distributor about 5’ away. I don’t see anything in the manuals prohibiting this and I am doing my best to satisfy all ABYC requirements. Anyone have any experience doing this? Thanks.
I have not done this personally but there are examples on here where people have done this to suit layout constraints. You will need to make some insulation covers over the exposed lugs.
I’m going to mention this, although it should go without saying.
As you haven’t supplied any electrical system details I’ll simply make the below comments which out regard to specifics.
The Lynx power rating is 1000Adc (https://www.victronenergy.com/upload/documents/Lynx_Distributor/24531-Lynx_Distributor_Manual-pdf-en.pdf).
Please ensure that should you choose to do this be mindful of your systems total current carrying potential, and that by introducing a cable, this will affect your systems ability to supply large system loads, even when using dual conductors. You’ll need to refer to the technical datasheet of your cable to establish it’s fixed and free air, Current Carrying Capacity.
Thanks for the responses everyone. Yes the limits of introducing the cable is a concern for sure. My installation in using a Lynx Smart BMS NG 500 amp model. For the 10 foot total DC circuit length the capacity with derating factor is 440 amps. I plan of fusing the 2 300ah 12.8v NG batteries with 200 amp fuses (in parallel). The multiplus will also be fused with a 400 amp fuse. I’d like like to avoid the additional resistance of putting a fuse in the bus bar cable if possible.
have a think about moving to 24v system, with lower currents, smaller cables and more tolerant of voltage drops…
Providing the battery output cables are suitably fused, as close as possible to the batteries this would be fine. The supply would disconnect from the system on a short / overload event at the supply source.
Above calculator is WRONG:
cable current carrying capacity is limited by the temperature rise. Some insulation types can tolerate a higher maximum temperature than others e.g. XPLE, Silicone, but also one must keep in mind if the cables are accessible to touch, then the max temp needs to be restricted to 55 - 60C, rather than 95C for high temperature cables. Given the above, I think the Victrons current capacity may be optimistic, mine may be conservative. Also bear in mind that MPPT cable currents may be sustained at high levels for 4 hours or so, whereas inverter cables rarely carry peak currents for any prolonged period.
Very confusing
I use a XTREM H07RN-F 1X50MM FLEXIBLE RUBBER SDI 90 DEGREE RATED 0.6/1KV as Battery cables yet by above Victron chart it can only carry 150amps up to 5 meters The manufacturer states 242Amps carrying capacity with No Length specified
The 90 degree insulation rating gives it a higher current rating than the above tables which are for PVC cables with 70 degree temp rating.
Also bear in mind that the ambient temperature affects the current rating, as any given current will cause a finite rise in temperature to be added to ambient. Limit is the insulation working temperature.
Do you have a good DC Multi-strand single core cable Calc
If as above the cable Xtrem H07RN-F 1x120mm² Single Core Rubber Cable Manufacturer states 437amps rated in Air not conduit which derates it ??
Does not seem right
https://www.solar-wind.co.uk/info/dc-cable-wire-sizing-tool-low-voltage-drop-calculator
I have a spreadsheet that I’ve developed over many years, based on a broad range of PVC cables.
If a manufacturer provides full current data for their cables, and most do, then use the manufacture’s information.
Cables in conduits are derated for two reasons:
I’ve put my calculator on Git at: GitHub - MikeD2-mnb/Cablecalc: spreadsheet for single core cable losses, current rating and other data. · GitHub
No liability whatsoever is accepted.
the link works for me: sorry I cant test it as being not me…but that is what Git provides as URL. link is public, but may take some time to work through the servers.
ok, checked on that.
Looks like the link expands as :http://www.mata-ni-bula.com/
the trailing “/” is automatically added by the Victron site and should not be there…
It’s not in the profile page. Not checked that before..
