Wiring Lynx Distributor to MultiPlus II

blutow

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My lynx setup connects a MPII w/SCC, 2 Orions, and the DC load center. It's a bit of a compromise and you need to size wires and fusing carefully when doubling up on single fuses. The wire used to each orion was big enough to work with the 100a fuse that covers the combined circuit. The scc and 12v load is more of a compromise because you potentially have power from the SCC running to the DC load side unfused (since that is all downstream of the fuse), but the SCC has short circuit shutoff built in. Again, it's a compromise, but I didn't think it was worth adding a separate fuse. I went with 2 x 2/0 runs to the multi because it worked out perfect with spools of 2/0 that I bought for battery runs also. It would have been fine running 4/0, it's just that much harder to work with and more expensive compared to 2x 2/0. 2 x 2/0 also supports more amps at less v drop compared to single 4/0.

1637358221711.png
 

corn18

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Nice install. I just finished the initial layout and wire setup. 4/0 wire to the MPII and it is a beast to work with, especially in freezing temps. But I got it laid out and what a clean setup.

I thought the manual said I needed a 4/0 chassis ground wire. It actually says I need a 4mm^2 which is a minimum 12 AWG. I am going to remove the 4/0 chassis ground and run something smaller.

IMG_5036.jpg

I still have some things to hook up and install there 400A class T fuse, but that will be easy.
 
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blutow

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Nice install. I just finished the initial layout and wire setup. 4/0 wire to the MPII and it is a beast to work with, especially in freezing temps. But I got it laid out and what a clean setup.

I thought the manual said I needed a 4/0 chassis ground wire. It actually says I need a 4mm^2 which is a minimum 12 AWG. I am going to remove the 4/0 chassis ground and run something smaller.

View attachment 72984

I still have some things to hook up and install there 400A class T fuse, but that will be easy.
I thought the Victron manual said ground should be as big as load, but it’s been a while since I installed mine. I just did a single 2/0 for ground, it would have been tough to manage 2 cables. I understand the logic of sizing ground the same in some worst case situations, but the primary role of ground is to provide another path (besides your body). A smaller cable will do that fine.
 

corn18

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I thought the Victron manual said ground should be as big as load, but it’s been a while since I installed mine. I just did a single 2/0 for ground, it would have been tough to manage 2 cables. I understand the logic of sizing ground the same in some worst case situations, but the primary role of ground is to provide another path (besides your body). A smaller cable will do that fine.
I thought I had read that, too. But I just re-read the manual and did a search of the online manual. This is all I could find in the Multiplus II 12/3000 manual:

Screen Shot 2021-11-20 at 14.59.58.png
 

corn18

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Another thing I noticed is the little red wire on the chassis ground connection. I cannot get it off to put the chassis ground connector under it. So the only contact area for the chassis ground wire is the little ring on that little red wire. That does not seem right. I would prefer to put the chassis ground connector under that little red wire, but I can't do that. Thoughts?

IMG_5038.jpg
 

SolarPrep

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There is a whole series of tutorials on youtube by a great guy who shows you how to modify a Lynx for more fuses. Very well done. Adventrues in RVing, or something like that. You will find it if you google. Anorher one is by Jono.
 

corn18

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There is a whole series of tutorials on youtube by a great guy who shows you how to modify a Lynx for more fuses. Very well done. Adventrues in RVing, or something like that. You will find it if you google. Anorher one is by Jono.
I think he modifies a Lynx power in for adding fuses but I have never seen one where someone added more fuses to a Lynx distributor.
 

blutow

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I think he modifies a Lynx power in for adding fuses but I have never seen one where someone added more fuses to a Lynx distributor.
Correct, but he does have a good video on how to enable the led’s on the lynx distributor without using the lynx shunt. They go red if you blow a fuse. All you need is a $5 voltage converter, simple hack. Not terribly useful functionality, but I hated having all those wasted electronics not being used.
 

corn18

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Correct, but he does have a good video on how to enable the led’s on the lynx distributor without using the lynx shunt. They go red if you blow a fuse. All you need is a $5 voltage converter, simple hack. Not terribly useful functionality, but I hated having all those wasted electronics not being used.
That is cool! I will be doing that mod.
 

corn18

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Just finished installing the Lynx distributor. Still have to do the LED mod (waiting for the 5v converter to come in). Really like how it turned out. I thought $205 was expensive for a distribution bar, but I priced out 2x400A Blue Sea Systems bars with covers and they are $80 each. And I got rid of 3 breakers @ $32 each. So I really should compare $205 for the Lynx to $256 for 2 quality 400A bus bars + 3 quality circuit breakers. The Lynx comes out ahead. And looks great. And I have one slot left on the Lynx. Life is good.

DC wiring 290RL lynx.jpg
 

after1985

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Just finished installing the Lynx distributor. Still have to do the LED mod (waiting for the 5v converter to come in). Really like how it turned out. I thought $205 was expensive for a distribution bar, but I priced out 2x400A Blue Sea Systems bars with covers and they are $80 each. And I got rid of 3 breakers @ $32 each. So I really should compare $205 for the Lynx to $256 for 2 quality 400A bus bars + 3 quality circuit breakers. The Lynx comes out ahead. And looks great. And I have one slot left on the Lynx. Life is good.

View attachment 73218




Hey everyone. I've been a bit of a lurker here for a while, but I finally registered. Rather than start a new thread immediately, I figured I'd reply to this one as it's a simple and related question:


Is there any major disadvantage to not using the left side buss bar connectors on the lynx distributor? I see that almost everyone uses those for the battery pos and neg connections, but It was my (incorrect?) understanding that those were meant to be used to link other Lynx products, like a Power-in, another Distributor, or the 1000A Shunt.

I like the idea of not having those big terminals exposed and so close together (see picture from corn18). My idea is to skip using those, and just use the 4 other connections for battery pos/neg, inverter, DC loads, and solar input, respectively - see photo:









Screenshot 2022-04-05 111537.png



I notice that almost everyone uses the bus bar extensions for their battery connections, but I have found a few examples that do not. For instance:

Screenshot 2022-04-05 112349.jpg



Further, the Lynx Distributor instruction manual states that when using just the Lynx distributor by itself (no 1000A shunt or Power-in attached like above examples), the do not recommend connecting anything using those external bus bar connections.


Screenshot 2022-04-05 113253.jpg


So, why does almost everyone use those connections when Victron advises against them?
 

smoothJoey

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Is there any major disadvantage to not using the left side buss bar connectors on the lynx distributor?
My opinion is...

That is a weird way to phrase your question :).

Victron would love to sell you more lynx components.

If you control the environment and take appropriate precautions the risk of connecting to the exposed backplane is minimal.
The exposed connections could be covered with shrink tube or Kapton tape to further minimize the risk.
Also if the system is behind a locked door and only competent people have access that would obviously be relevant.

Batteries should be fused as close as possible to the positive terminal to minimize the chance for an up-steam short.
So if you connect those batteries to a fused position then you will have 2 fuses on the same circuit.
Which is redundant and increases the resistance of the circuit.
Nevertheless some people do this.
Others would attach a lynx power-in to the left hand side and attach their batteries to the un-fused branch positions of the power-in.
If you do that, then you are pretty likely to add a lynx shunt in between which is >$400.00USD at the time of this post.
The expense starts to add up.

tl;dr Victron "lego" is expensive.
 

BretS

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Hey everyone. I've been a bit of a lurker here for a while, but I finally registered. Rather than start a new thread immediately, I figured I'd reply to this one as it's a simple and related question:


Is there any major disadvantage to not using the left side buss bar connectors on the lynx distributor? I see that almost everyone uses those for the battery pos and neg connections, but It was my (incorrect?) understanding that those were meant to be used to link other Lynx products, like a Power-in, another Distributor, or the 1000A Shunt.

I like the idea of not having those big terminals exposed and so close together (see picture from corn18). My idea is to skip using those, and just use the 4 other connections for battery pos/neg, inverter, DC loads, and solar input, respectively - see photo:









View attachment 90050



I notice that almost everyone uses the bus bar extensions for their battery connections, but I have found a few examples that do not. For instance:

View attachment 90053



Further, the Lynx Distributor instruction manual states that when using just the Lynx distributor by itself (no 1000A shunt or Power-in attached like above examples), the do not recommend connecting anything using those external bus bar connections.


View attachment 90054


So, why does almost everyone use those connections when Victron advises against them?

My reasoning is pretty simple... I needed to put 10# of $hit in a 5# sack😁 space is a premium in my application, so I used them. The manual says you can use them, they don’t recommend it because additional insulation and fusing is needed - so just fuse and insulate... no problem.
 

after1985

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Joined
Apr 5, 2022
Messages
17
My opinion is...

That is a weird way to phrase your question :).

Victron would love to sell you more lynx components.

If you control the environment and take appropriate precautions the risk of connecting to the exposed backplane is minimal.
The exposed connections could be covered with shrink tube or Kapton tape to further minimize the risk.
Also if the system is behind a locked door and only competent people have access that would obviously be relevant.

Batteries should be fused as close as possible to the positive terminal to minimize the chance for an up-steam short.
So if you connect those batteries to a fused position then you will have 2 fuses on the same circuit.
Which is redundant and increases the resistance of the circuit.
Nevertheless some people do this.
Others would attach a lynx power-in to the left hand side and attach their batteries to the un-fused branch positions of the power-in.
If you do that, then you are pretty likely to add a lynx shunt in between which is >$400.00USD at the time of this post.
The expense starts to add up.

tl;dr Victron "lego" is expensive.


Hah, fair point, that question was worded in a "tell me why I need more legos" kind of way.

I definitely want to avoid that shunt and power in at all costs. My system is too simple for it anyway. But, it gave me an idea. Supposing I use the Lynx the way I want to (not using the left-hand side connections): I could connect the battery directly to the M8 bolt on the main bus bar and effectively bypass the middle m8 bolt and dispense with the need for a mega fuse there. In effect, for the battery connection it would be more like a Lynx power in, but the other three connections would be mega-fused. Then, I could put my T-fuse closer to the battery as recommended, and not have two fuses on the same circuit.
 

smoothJoey

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Nov 30, 2019
Messages
11,833
Hah, fair point, that question was worded in a "tell me why I need more legos" kind of way.

I definitely want to avoid that shunt and power in at all costs. My system is too simple for it anyway. But, it gave me an idea. Supposing I use the Lynx the way I want to (not using the left-hand side connections): I could connect the battery directly to the M8 bolt on the main bus bar and effectively bypass the middle m8 bolt and dispense with the need for a mega fuse there. In effect, for the battery connection it would be more like a Lynx power in, but the other three connections would be mega-fused. Then, I could put my T-fuse closer to the battery as recommended, and not have two fuses on the same circuit.
Or you could follow this video and add fuses to the less expensive power in on the positions that need them.
 

corn18

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Sep 9, 2021
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453
I don't see any reason you have to use the large inputs on the left side. But it eats up a fuse slot. And I wanted my class T main fuse as close to the batteries as possible. I did remove the 4/0 cable from the shunt to the neg distributor input and just bolted the shunt directly to the distributor. Works like a champ. The cutoff switch is also bolted directly to the distributor.

DC wiring 290RL rev 1 install.jpg
 
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after1985

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Apr 5, 2022
Messages
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I don't see any reason you have to use the large inputs on the left side. But it eats up a fuse slot. And I wanted my class T main fuse as close to the batteries as possible. I did remove the 4/0 cable from the shunt to the neg distributor input and just bolted the shunt directly to the distributor. Works like a champ. The cutoff switch is also bolted directly to the distributor.

View attachment 90067


Did you just drill/ream the distributor holes to M10 or 3/8ish size to make those fit?
 
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