Eltek 3kw x3 as 9kw

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Scrappyjoe
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Eltek 3kw x3 as 9kw

Post by Scrappyjoe »

Hello,

I have 3x Eltek 3kw chargers. I think the history is they originally came from arber, and came to me via Zapatero. I am interested in wiring them up to make 9kw, and have some questions.

1. I was wondering if anyone had instructions on how to wire them in 3 phase configuration?

2. Zapatero said that, once wired up, I could plug 2 into a single phase house for 6kw, but could only plug in 3 if it was 3 phase because I would need to match the phases. I’d like to confirm if this is correct, since, my limited understanding is that, since these are isolated units, which are all putting out 350v DC, I can’t see why they have to be ‘true’ 3 phase.

3. If I wire them up as completely separate chargers, with separate 220V ac inputs, but all going to the same HV DC rail, could I attach them to 3 separate petrol generators? I am thinking here of a recharge option for my once-in-a-year long overland camping trip.

4. I would hate to run a generator at a camp site, but figured if I put 3 rented 3kw generators on a small trailer, and set up the Elteks to charge while I am moving, I can get 9kw ‘recharge while moving’, extending my range. Please tell me why this is a (technically) bad idea, if it is.
arber333
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Re: Eltek 3kw x3 as 9kw

Post by arber333 »

Scrappyjoe wrote: Mon Apr 01, 2024 1:23 pm Hello,
......
1. I was wondering if anyone had instructions on how to wire them in 3 phase configuration?
Observe this post and links to my site...
viewtopic.php?p=63766#p63766
https://leafdriveblog.wordpress.com/201 ... w-charger/
https://leafdriveblog.wordpress.com/202 ... ogramming/
https://leafdriveblog.wordpress.com/202 ... -chargers/
2. Zapatero said that, once wired up, I could plug 2 into a single phase house for 6kw, but could only plug in 3 if it was 3 phase because I would need to match the phases. I’d like to confirm if this is correct, since, my limited understanding is that, since these are isolated units, which are all putting out 350v DC, I can’t see why they have to be ‘true’ 3 phase.
I only tested it on 3 phase but i dont see any reason they all wouldnt work well from single phase.
However when you run them from 3phase you need to reprogram them to each its own address. Address is connected with return messages and many have stated they had Eltek chargers stopped working when they used them in 3phase with common N. I wired them the same AND then i reprogrammed them to respective addreses but kept command at 02FF. I havent had any problems with that...
See CAN bus protocol.
3. If I wire them up as completely separate chargers, with separate 220V ac inputs, but all going to the same HV DC rail, could I attach them to 3 separate petrol generators? I am thinking here of a recharge option for my once-in-a-year long overland camping trip.
Sure, they are isolated chargers.
4. I would hate to run a generator at a camp site, but figured if I put 3 rented 3kw generators on a small trailer, and set up the Elteks to charge while I am moving, I can get 9kw ‘recharge while moving’, extending my range. Please tell me why this is a (technically) bad idea, if it is.
I am not sure EV regulations allow you to charge battery while driving. Might check up on your legislation.
Otherwise i dont see a problem with your idea. Tesla charger for example could be used from either 3x single phase or simply 3phase wiring with common N line since it is 3x chargers inside one casing.

But you might add a ower diode on the HV output of each charger to keep stray currents from jumping between chargers while driving. There is a lot happening on the DC rail then...
Attachments
Eltek_CANbus_Protocol.pdf
(114.3 KiB) Downloaded 27 times
Scrappyjoe
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Re: Eltek 3kw x3 as 9kw

Post by Scrappyjoe »

Thanks arber, that reply hits every single one of my questions!

Perhaps a more obvious one. My canbus network is terminated by a Zombieverter on one end and an IVT shunt on the other (it has an internal resistor).

Am I correct in assuming I can connect these chargers (plus my outlander heater and AC) to the same can line, along with an (unterminated) arduino due for control?

Are there any requirements in terms of connection order?

This is the magic of CAN as far as I am aware - it’s like everything is in the same chat group :)
arber333
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Re: Eltek 3kw x3 as 9kw

Post by arber333 »

Scrappyjoe wrote: Mon Apr 01, 2024 8:04 pm Thanks arber, that reply hits every single one of my questions!

Perhaps a more obvious one. My canbus network is terminated by a Zombieverter on one end and an IVT shunt on the other (it has an internal resistor).

Am I correct in assuming I can connect these chargers (plus my outlander heater and AC) to the same can line, along with an (unterminated) arduino due for control?

Are there any requirements in terms of connection order?

This is the magic of CAN as far as I am aware - it’s like everything is in the same chat group :)
Well terminating resistors should be at each other ends of that network. No other device should have termination inside. That is about it.

The best way to test this would be to make connection and then measure by ohm meter. You should see 60R resistance. If it is more or much less there is something wrong...

You can remove resistor from VCU or ISA if you need to... just maybe not worth it.
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