Nations 280A Alternator + Wakespeed. 2/0 recommended?

[syspig]

I've an auxiliary alternator coming from Nations for my E450 chassis, it will be dedicated to charging my 4x200AHLifeblue lithium bank. Controlled by a Wakespeed, but it won't be tied into a BMS.

Perhaps I should have researched it more, but I blindly went ahead and ordered up 2/0 cable for the alternator to busbar connection. Per Nations, they said 2/0 was fine up to a 20' run, anything longer they would suggest 4/0. My run is 15' at most, probably closer to 10'.

In looking at some wiring charts, it appears 2/0 is only good up to 190A. Yes, ignorance no doubt showing here - but how can that be acceptable for an alternator that can put out 280A? Yes, I do realize that's its rated maximum, and I've no clue what real world throughput I'll see from it under various SOC and engine RPM's.

I don't mind paying extra for 4/0, but it would certainly make the installation more difficult in my case. Wire routing is tight, and 2/0 would be much easier to install.

 

[HarryN]

While I am not a big fan of wakespeed ( the people there ) , it does include the ability to limit the nominal amp output of the alternator.

It limits "on average", not a hard limit. So you can still have times when the peak will exceed the alternator label rating, especially under strong acceleration. It is impossible for any alternator controller to completely hard limit an alternator, no matter who builds it.

Make sure to include a way to prevent the alternator from ever being disconnected from a battery, no matter what, or it will blow out the alternator almost instantly. Also true of any alternator.

Just curious, did nations approve running that setup without a bms feeding info back to the wakespeed ?

 

[justinm001]

Correct, if you want more than 190A you'll need to get larger cable. With the wakespeed you can limit the amperage and 190a is 70% of 280a which is normal duty rating for an alternator unless that's a commercial/industrial rated for 100% constant.

That alternator won't last long if you're pumping 280amps from it.

 

[justinm001]

While I am not a big fan of wakespeed ( the people there ) , it does include the ability to limit the nominal amp output of the alternator.

It limits "on average", not a hard limit. So you can still have times when the peak will exceed the alternator label rating, especially under strong acceleration. It is impossible for any alternator controller to completely hard limit an alternator, no matter who builds it.

Make sure to include a way to prevent the alternator from ever being disconnected from a battery, no matter what, or it will blow out the alternator almost instantly. Also true of any alternator.

Just curious, did nations approve running that setup without a bms feeding info back to the wakespeed ?

You don't need a BMS to feed into the wakespeed as they have all the wires to monitor it themselves. Wakespeed works great at limiting amperage maybe it'll average by the second but that's all.

They make a device to prevent the alternator from being backfed high voltage. Sterling makes it.

 

[syspig]

Correct, if you want more than 190A you'll need to get larger cable. With the wakespeed you can limit the amperage and 190a is 70% of 280a which is normal duty rating for an alternator unless that's a commercial/industrial rated for 100% constant.

That alternator won't last long if you're pumping 280amps from it.

I've had the same setup (4x200 Lifeblues, Victron Multiplus) in two other rigs, so I've a pretty good feel for usage and how long things last even with minimal solar. I've never dropped below 20% SOC boondocking for a week straight, even with typically bad winter solar conditions. The only thing new is the dual alternator/Wakespeed setup, and if needed - the plan would be to simply idle the coach motor for an hour here or there. Understanding of course, the output would be significantly less at idle.


Point being, even with SOC down to 20% it looks like a 3-4 hour drive would come close to bringing the bank back to 100% at 190A. That's very typical for how I travel, so yeah - I think I could live with configuring the Wakespeed for 190A max.

Thanks for the info.

 

[syspig]

Just curious, did nations approve running that setup without a bms feeding info back to the wakespeed ?

I spoke with them at length on my planned setup prior to purchasing. They're aware no BMS feedback would be provided.

I'm still trying to learn as much as I can about this new (to me) setup, but in the Wakespeed manual they do show a typical install without BMS feedback. See attached.

I know I can tie the Wakespeed into the Cerbo as well, but it's not clear to me yet what all that might provide. From what I've been able to ascertain, I think that simply gives reporting - not control - from the Cerbo console. I'd welcome any feedback on that as well from those in the know.

 

[justinm001]

I spoke with them at length on my planned setup prior to purchasing. They're aware no BMS feedback would be provided.

I'm still trying to learn as much as I can about this new (to me) setup, but in the Wakespeed manual they do show a typical install without BMS feedback. See attached.

I know I can tie the Wakespeed into the Cerbo as well, but it's not clear to me yet what all that might provide. From what I've been able to ascertain, I think that simply gives reporting - not control - from the Cerbo console. I'd welcome any feedback on that as well from those in the know.

Correct it gives reporting which is really nice as you can see how much it's making and anything else. No control over it. I'm not sure if it can use SoC or anything else from the cerbo. Very nice when there's an error as it'll report on the cerbo

I wired mine without a BMS and it worked fine. I was pleasantly surprised how well the wakespeed worked. Doesn't work for my setup anymore but was pretty good once you know how to program and use.

 

[justinm001]

I've had the same setup (4x200 Lifeblues, Victron Multiplus) in two other rigs, so I've a pretty good feel for usage and how long things last even with minimal solar. I've never dropped below 20% SOC boondocking for a week straight, even with typically bad winter solar conditions. The only thing new is the dual alternator/Wakespeed setup, and if needed - the plan would be to simply idle the coach motor for an hour here or there. Understanding of course, the output would be significantly less at idle.


Point being, even with SOC down to 20% it looks like a 3-4 hour drive would come close to bringing the bank back to 100% at 190A. That's very typical for how I travel, so yeah - I think I could live with configuring the Wakespeed for 190A max.

Thanks for the info.

It says that alt idles at 200amps so you might be able to just set it and leave it. You might have a high idle option/PTO so it'll have plenty of power. Another option is you can wire up a switch to the wakespeed and have the profile change so you can have it change to 100a or 190a by flipping a switch.

Its much better to have a bigger alt than you need. It'll stay nice and cool when running well under max

 

[jorby]

It says that alt idles at 200amps so you might be able to just set it and leave it. You might have a high idle option/PTO so it'll have plenty of power. Another option is you can wire up a switch to the wakespeed and have the profile change so you can have it change to 100a or 190a by flipping a switch.

Its much better to have a bigger alt than you need. It'll stay nice and cool when running well under max

I agree completely, but "Nice and cool" is relative. I wouldn't put my lips on it!