External transfer switch 100M current sensor length

Q&A and troubleshooting
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1

Hi,

currently designing ESS system for a customer.

The mains supply is 3x80A and the current SMA PV inverter has 3x72.5A output current.

the design consist of 6 multiplus-ii 48/15KVA inverters 2 for each phase. therefore an external transfer switch is needed and anti-island protection. Due to insurance regulations the ESS system will be build in a 20 ft container placed behind the building. however this means the cable run will be between 90-100M 1 direction

the traditional way of running 2 cables is not preferable due to cable cost and voltage drop. However I only see the maximum length of the Current sensor 20M. is it possible to extend this or alternatively to use something like the EM375 and connect over VE.Bus?

20m max cable is not possible as it would be to close to the building.

Would like to hear your feedback :slight_smile:

Cheers

Dennis

2

I haven’t tried it longer but will comment on known issues for why it is limited- they are related to signal degradation which would introduce inaccuracies.

It is low level current based on the current it is exposed to. Then add the resistance of a long thin cable and then things aren’t going to go well. Long wires end up with capacitance betwee them further adding complications.

I hear what you are saying though. I would love to have the option to use the external transfer set up further from source.