Which CT?


I'm trying to monitor a 3 phase load which'll be 0-125amps, I believe I can use a SCT-019-150 which is a 19mm CT upto 150amps with voltage output (i.e the resistor is on the CT) so it's just plug and plug into a emonTxV3

Can someone kindly confirm?



Robert Wall's picture

Re: Which CT?

That's not a good choice as it only outputs 0.333 V rms at rated current, so you're wasting two thirds of the range of the emonTx. And you'd need to remove the internal burden resistor anyway.

A better choice would be the -000 variant, remove the emonTx's internal burden resistor on the channel you will be using, and fit a 51 Ω (or a 47 Ω if you can't get a 51) in the holes provided. The 51 Ω will give you full scale at about 130 A, and the 47 Ω at about 141 A.

wuciwug's picture

Re: Which CT?


If I want to have about 5 of these (i.e 15 cicuits) I assume they're individually identifiable on the wireless frequency, I.e I could have one pi talking to 5 bases?



Bbaass_TMH's picture

Re: Which CT?

One emonBase or emonPi can receive data from multiple emonTx's, yes.

If you need to have more than 2 emonTx's you will also need the mini-USB to UART programmer to set the node ID in the emonTx software.

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