Hi, I’m looking for some advice about the number and rating of split core CTs I should purchase with the Aussie bundle.
I think I have three phase power and would use derived reference, but I am not sure how many 100 A and 50 A CTs I will need.
Attached is a photo of my switchboard, thanks.
There are plenty of Australian users of IoTaWatt, so I was hoping someone more familiar with the local equipment would respond, and that may yet happen. From what I can see you do have three-phase supply as well as a three phase solar inverter. There appear to be 8 additional circuits as well.
To monitor everything, it appears you would need:
3x100A CTs for the mains
3x50A CTs for the solar inverter
8x50A CTs for the other circuits.
That’s a total of 14 CTs, which is the capacity of the IoTaWatt using derived reference.
As outlined in the stuff site, it’s best to get the VT and USB power supply locally from one of the sources referenced. When the CTs are installed, they should all be oriented the same way with respect to line/load to avoid problems configuring the derived reference. It would be helpful as well if your electrician would label which mains phase is associated with each branch circuit, and which mains phase feeds the outlet where you plug the VT.
A 3 phase inverter is unusual, particularly for a domestic installation. However it does appear to have a three phase main switch. It may be only one pole is being used to isolate the active or two poles to isolate active and neutral for the solar. You electrician can confirm this. If its only a single phase inverter then you only need one 50A CT for solar.
Is the solar command unit on the left a power export limiter ? How many kW of solar do you have installed ?
Thanks both for the advice. I’ll go with 14 CTs.
My inverter is a Fronius Symo 5.0-3, which is indeed 3 phase.
Your guess is as good as mine (or probably better). The solar was installed before I purchased the house. I did some half-hearted googling after first moving in to figure out what it was, and found something about Solar Command being a type of subscription-based remote monitoring of solar generation. I didn’t dig any further because I was already using pvoutput directly through the inverter.
I have 5.2 kW of solar over 20 panels.
You can get away with 10 CT’s
3 for mains
3 for solar
1 for Air con
1 for oven
You have 4 power circuits and 2 light circuits.
It depends if you want to monitor each circuit or lights and power as a total.
You can run the 4 power outputs (depending on wire length availability in the board) through 1 CT and the 2 light circuits though another CT
This is how I have mine set up, so that I get a total on my 3 power circuits from 1 CT.
Same with my 2 light circuits through 1 CT.
