Lynx Power In really 1000A ?

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myhomebuzz asked Nov 27, '21

Lynx Power In really 1000A ?

The Lynx Power In, like the Distributor, are advertised with an intensity of 1000A. Without going into the technical details of scientific calculation, we take an average of 1.2A per mm2 (maximum of 3A per mm2 according to the calculation bases of one of the 3 world leaders in professional electrical boxes and safety for busbars). However, the two Lynx have a bar of 30 * 8 mm. This gives 240 mm2. We multiply by the technical average of 1.2 and the result is 288A, or by the maximum of 3, the result is 720A, but never the 1000A. Do you have more information to send me on this subject? Thanks in advance.

amps busbar

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Answer 1 · 2021-11-29T16:15:52Z

Alexandra answered · Nov 29, 2021 at 04:15 PM

@MyHomeBuzz

I think it would be 1000A peak, not 1000A constant. (Edited from rms as it is incorrect refernce, as I was really referring to a sustained or constant current) I do see the logic and maths in the calculations.

But the question is sort of a moot point. There is not system that can connect to the few points to rms the amps on that bar.

1000x48v it a 48kva system. When building that big you will need alot more space and better current sharing anyway so would not use it? I personally would not use it on those systems as a better setup for current sharing and heat dissipation is needed.

At 12v 1000A thats a 12kva system. I don't know any 12kva at 12v? I could be corrected, would rather think it is an ultra daft setup anyway the poor batteries never mind the bus bar.

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myhomebuzz commented · Nov 29, 2021 at 04:53 PM

@Alexandra

Thanks for feedback.

The calculation does not depend on logic, but on a mathematical fact.

The point is that Victron advertises 1000A on a 30x8mm bus bar, in the technical brochures as well as on the product.

Whether or not one uses the maximum intensity is not the question. The question is: is it correct that the intensity of the Lynx Power In is indeed possible with 1000A?

A simple example with only a Multiplus II 12-3000: when using peak of 6000W, this gives an intensity of 500A with cables in 2 x 50 mm2 positive and 2 x 50 mm2 negative (which is correct according to the formula S). So if we take the calculation of 30x8 mm => 240mm2 and 240 * 1.2 (temperature rise, k factor ..) => 288A, we are weak. But with a factor of 3 at the limit threshold (720A), it's good. But still no 1000A. And the calculation can also be done in 36, 48 or 2000V, where and how the information of 1000A is brought? This is my question

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kevgermany ♦♦ myhomebuzz commented · Nov 29, 2021 at 05:41 PM

This is really a question for Victron tech support not the user community.

I think many of us would be interested in the answer, though.

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myhomebuzz kevgermany ♦♦ commented · Nov 29, 2021 at 05:47 PM

@kevgermany

For sure. But since there are a lot of Victron Energy staff on this forum, I thought that an answer could be given directly to the whole community.

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kevgermany ♦♦ myhomebuzz commented · Nov 29, 2021 at 05:52 PM

They tend to reply if tagged directly.

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Phil Gavin commented · Nov 29, 2021 at 05:13 PM

"I think it would be 1000A peak, not 1000A rms."

-It's DC.

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myhomebuzz Phil Gavin commented · Nov 29, 2021 at 05:50 PM

@Phil Gavin

Maybe Phil, maybe.

But this is not demonstrated or correctly informed.

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Answer 2 · 2021-11-30T06:54:04Z

Guy Stewart (Victron Community Manager) answered · Nov 30, 2021 at 06:54 AM

Hi @MyHomeBuzz,

A lot of limits in power electronics are related to heat, and the capacity of the adjacent materials to withstand it, and how it is dissipated, that would be an integral part of the rated capacity and one that is not accounted for in typically conservative generalised information.

There is an extreme amount of info related to the details in this document if someone was really wanting to investigate for themselves.

http://copperalliance.org.uk/uploads/2018/03/section-2-0-current-carrying-capacity-of-busbars.pdf

While perhaps not intellectually satisfying, the Lynx distribution system has been deployed in many thousands of systems, and I have never heard of anyone ever overloading the bars leading to an issue.

I have heard and seen people inadequately connecting to the bars, and that leading to issues at the point of connection, but never the bars themselves.

Unless there is some instance of the rated current (or even less than) leading to an issue with a system, I don't think I can get much more internal info than what is published in the long standing spec.

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myhomebuzz commented · Nov 30, 2021 at 07:53 PM

Hi @Guy Stewart (Victron Community Manager)

I understand your answer or rather your point of view.

It is not because thousands or millions of people use a system that works, moreover, but the statement that goes with it. If we entered 200000A on a data sheet of a product, the same thousands of people would use the product without asking questions? Or what if the actual maximum current of 480A of a Lynx Power In bus bar was indicated? I doubt it too.

This calculation of 480A for a 30 x 8 mm bus bar is that given mathematically and physically tested by the CDA of the National Physical Laboratory in Teddington and in the US. The same as the link you transmitted. As a reminder: Amax = 24.9 • ( S^.5 • p^.39 • θ^.61 / √ ρ • (1 + α (θ + 10) ) ) for an ambient temperature of 30° Celsius.

We can assume that Victron simply indicated 1000A for the two bus bars, but this does not work like that. Let's look at the Lynx Shunt which is marked 500A with the same bus bar.

I am a Victron fan and have no doubts, however an effective answer would be appreciated on the calculation procedure for this advertised 1000A bus bar. A point of view on sales or accomplishments is not a technical statement. But it is the fruit of a leading company in its field which provides innovative technical solutions with certification.

That's why I'm a Victron fan.

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Answer 3 · 2022-12-22T21:25:37Z

oyfant answered · Dec 22, 2022 at 09:25 PM

Propably wery interesting for a insurance company in case of fire and documentation?

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Answer 4 · 2022-12-22T21:42:40Z

pyrorider answered · Dec 22, 2022 at 09:42 PM

When calculating the power loss of the lynx power in at 48V I get 0.0432V lost on the 2 29cm busbars, at full 1000A load that would be 43W of power lost (0.0009%). So as long as victron says that the enclosure can dissipate the 43W there shouldt be a problem

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Answer 5 · 2022-12-30T01:08:56Z

@Guy Stewart (Victron Community Manager)

Using 48V for your calculations is not realistic as you would probably find under a load of 1000A, voltage would be significantly lower and would effect heat dissipation. I also wondered about the "1000A" rating when I first opened the Lynx a long while back, thinking that the bus bars are undersized. If you derate your 1000A by 0.8 which would be a standard acceptable calculation when using DC @30C ambient inline with ABB or Schneider DC de-ratings you would find that your maximum rating for constant current would be @800A less additional derating with the correct factor as the ambient temperature increases. I hope no engineer would design and spec a circuit to load a 1000A on a product with 1000A rating. Minimum would be to design with the correct derating factor from the manufacturer. I would not design a circuit with more than 0.6 to 0.8 constant current of the max rated current at the specified temperature regardless of been asked to cut cost and push it the edge, especially using DC.

In summary In this scenario I would say that 0.8 derating @30C of the maximum current spec is a sensible idea, like I said I would probably be more inclined to consider ambient operation temperatures around the bus bar including being classed as "in an enclosure" and you would probably find that at 60C you would be sitting @600A at continuous current draw for any significant period of time. I think Victron are speccing their Lynx at the top end of what it can handle for a short period of time which is what most manufacturers will do. Maybe Victron should get their engineers to add some de-rating factors into the documentation to satisfy questions like this. But again going back to the engineering side of it, no engineer would design the circuit around 1000A anyway, atleast I would hope not. Just in the same way I see plenty of Multiplus and Quattros fitted closer than 100mm to trunking and other components when they shouldn't be. You will find most DC de-ratings are 0.8 @30C with quite a large decline in reducing the factoring for every 10 degrees C. Like I said I don't think 1000A is an unreasonable claim when backed up with the correct de-rating factors from Victron, which really they should publish to satisfy the consumer. You will probably find that if they listen to this post and publish the additional data I wouldn't be surprise to see it drop to 500-600A for continuous load in an enclosure in an engine room at 40-60C.

Stay safe,

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