CT coils for ME3000 inverters in parallel

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ivan
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Joined: Thu Nov 14, 2024 12:18 pm

CT coils for ME3000 inverters in parallel

#1

Post by ivan »

Over the next few weeks Im going to have a go at wiring up my second ME3000 in parallel to my existing one, using this wiring guide, posted by tinbum way back in Jan 23:

https://postimg.cc/Y4vcWWmq

So it looks like I'll need 5 CT coils, but I only have 4. What do I use for the 5th one? Not sure what the difference is between different types of CT coil, or how standardised they are. I've got some spare small blue CT coils which I've used with the eMON power meter I built - would these suitable? Or do I need to buy a Sofar Solar coil from somewhere?
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Tinbum
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Re: CT coils for ME3000 inverters in parallel

#2

Post by Tinbum »

If i remember rightly the coils are 1:3000 ratio.
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nowty
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Re: CT coils for ME3000 inverters in parallel

#3

Post by nowty »

Search for "sofar me3000sp ct" on ebay, loads for sale.
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ivan
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Re: CT coils for ME3000 inverters in parallel

#4

Post by ivan »

Perfect - found them on ebay. Yes, you're right - 3000/1 - I hadn't realised it was printed on the clamp itself! It's the 0-150A.

Incidentally, do you know how the two inverters work together in this configuration - do they split the load equally, or does the master do the first 3kW then the slave take over from the master if load>3kW and/or master inverter battery runs flat?

BTW, I asked Sofar several years ago if you could parallel two inverters for 6kW power handling and they said it wasn't possible!!
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SimonSays
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Re: CT coils for ME3000 inverters in parallel

#5

Post by SimonSays »

The master inverter is trying to minimise the current in it's two CT clamps, up to it's 3kW limit.
When the load is beyond the master inverter's capability, current will appear in the slave inverter's CT clamp and it'll start discharging to try to reduce that to zero.
So the master inverter is carrying the majority of the load with the slave only assisting when the load is above 3kW.
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ivan
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Re: CT coils for ME3000 inverters in parallel

#6

Post by ivan »

Thankyou - perfect explanation! I've ordered the parts to get my slave inverter up and running, but they forgot to include the fuses for some reason, so I'm waiting for them to arrive.
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