Current Transformers

Continental Control Systems sells several different series of current transformers (CTs) in various window sizes, current ranges, and accuracy grades. Most WattNode meters use voltage output CTs (not current output ratio CTs) CTs are suitable for use in dry (indoor) locations in 50 or 60 Hz services up to 600 Vac. Low-voltage output CTs contain a built-in burden resistor and are calibrated to output 0.333 Vac when the CT’s rated full-scale current flows through the conductor being measured. Safe, low-voltage output CTs do not need shorting blocks because the internal burden resistor is always connected.

To select a CT, we recommend first deciding on a style, either a split-core (opening ) or a solid-core (non-opening) CT, then select the model you need based on the maximum load current you are measuring and the size of the conductor being measured.

• For complete specifications, available current ranges, and datasheet downloads click on the individual series part number links in the tables below.

Current Transformer Line Card

• CT Line Card (PDF, 1 page)

0.333 V Output CTs

Family (click on link)	Window	Amp Ranges	Accuracy
ACTL-0750 Split-Core CT	0.75 x 0.75 in.	5 to 250 A	1.0%, 0.5%
ACTL-1250 Split-Core CT	1.25 x 1.83 in.	250 to 600 A	1.0%, 0.5%, 0.3%
CTBL Large Split-Core CT	Varies	800 to 6000 A	1.5%
CTML-0350 Split-Core CT	0.36 x 36  in.	5 to 70 A	1.0%
RCSL-RCLL Rogowski Coil	1.5 to 11.8	200 to 5000A	1.0%
CTRC Rogowski Coil	3.1 to 12 in. dia.	250 to 6000 A	1.0%
CTS Split-Core CT	2.0 x 2.0 in.	400 to 1200 A	1.0%
CTT Solid-Core CT	0.3 to 1.25 in.	5 to 400 A	1.0%
TCL-B Solid-Core CT	0.5 in. dia.	50 A, 100 A	0.3%, 0.2%