As standard, with all 3-phase hybrid inverters and AC chargers, Fox supply a Chint DTSU666 modbus meter with CTs. The supplied CTs are split-core and rated to 200/5A.
These CTs are not suitable for all applications, and CTs with a higher rating and larger aperture diameter are sometimes required.
While Fox do not supply larger CTs, they can be sourced from suppliers and anything with a primary current of up to 1000A is suitable – providing the secondary current is 5A.
You must adjust the CT ratio within the meter settings if installing larger CTs. By default this is set to 40 (for standard 200/5A CTs); therefore if you install CTs rated to, say, 400/5A, you would need to adjust the ratio to 80.
A simple calculation can be made to determine what CT ratio the chint meter will need to be set to:
CT Ratio = Primary / Secondary
Forxample if you are using a 1000/5a CT clamp simply divide 1000 by 5, this will give you the CT ratio settinf of 200.
Below is a guid on how to change the CT ratio.
