Current Transformers

The NetMeter-3P requires current transformers (CTs) to detect the load current.
CTs are chosen for your application based on:

  • The current rating of the circuit to be monitored
  • The physical size of the conductor or bus bar that each CT will be attached to
  • Ease of installation: "split core" CTs allow for installation without having to physically disconnect

CTs are available from Z3 Controls and other vendors.

The NetMeter typically uses split core CT's that include a burden resistor and output 0.333VAC at rated output (this is one of the most popular CT types).

Current mode CTs (unburdened CTs) must be used with an appropriately sized burden resistor in order to be used with the NetMeter. Without the proper burden resistor, current mode CTs will damage the NetMeter. Current mode CTs produce dangerous voltages when unburdened.


This is a list of popular CT types available from Z3 Controls (call for other options as required):

Split core 0.75" opening (A=2.0", B=2.1", C=0.61", D=0.75", E=0.75")
Current Capacity Part # Diagram
5 Amp SCT-0750-005
20 Amp SCT-0750-020
30 Amp SCT-0750-030
50 Amp SCT-0750-050
70 Amp SCT-0750-070
100 Amp SCT-0750-100
150 Amp SCT-0750-150
200 Amp SCT-0750-200
Split core 1.25" opening (A=3.25", B=3.35", C=1.0", D=1.25", E=1.25")
Current Capacity Part # Diagram
200 Amp SCT-1250-200
250 Amp SCT-1250-250
300 Amp SCT-1250-300
400 Amp SCT-1250-400
600 Amp SCT-1250-600
Split core 2" opening (A=4.75", B=5.0", C=1.2", D=2.0", E=2.0")
Current Capacity Part # Diagram
400 Amp SCT-2000-400
600 Amp SCT-2000-600
800 Amp SCT-2000-800
1000 Amp SCT-2000-1000
1200 Amp SCT-2000-1200
1500 Amp SCT-2000-1500
Split core 3"x5" opening (A=5.75", B=7.50", C=1.20", D=3.00", E=5.00")
Current Capacity Part # Diagram
400 Amp SCT-3000-400
600 Amp SCT-3000-600
800 Amp SCT-3000-800
1000 Amp SCT-3000-1000
1200 Amp SCT-3000-1200
1500 Amp SCT-3000-1500
2000 Amp SCT-3000-2000
3000 Amp SCT-3000-3000