Current Transformers
Continental Control Systems sells several different families of current transformers (CTs) in various window sizes, current ranges, and accuracy grades. To select a CT, we recommend first deciding on an opening (split-core) CT or a solid-core CT, then select the size you need based on the current you are measuring or the size of the conductor you are monitoring.
Split-Core Current Transformers
| Split-core CTs (opening) have an opening section, so that they can be installed without interrupting the circuit. They are available in many current ratings and window sizes to fit one or more conductors. |  |
| Family | Rectangular Window | Amp Range | Accuracy(1) | Phase Angle(1) | MSRP |
|---|---|---|---|---|---|
| CTM-0360 | 0.30 in. | 5-70 A | 1.0% | < 2.0° | $29 |
| ACT-0750 | 0.78 in. | 5-250 A | 0.75% | < 0.5° | $42 |
| ACT-0750 C0.6 | 0.78 in. | 30-250 A | 0.5% | < 0.25° | $55 |
| CTS-0750 | 0.75 in. | 5-200 A | 1.0% | < 2.0° (2) | $45 |
| CTS-1250 | 1.25 in. | 70-600 A | 1.0% | < 2.0° (3) | $48 |
| CTS-2000 | 2.00 in. | 400-1500 A | 1.0% | < 2.0° | $68 |
| CTB | Up to 12x12 in. | 150-6000 A | 1.5% (4) | < 1.5° | Varies |
- (1) The accuracy and phase angle specifications are generally from 10% to 100% of rated current. ACT-0750 models are specified from 1% to 100% of rated current.
- (2) The phase angle is not specified for models CTS-0750-005, CTS-0750-015, CTS-0750-030, and CTS-0750-050
- (3) The phase angle is not specified for models CTS-1250-070 and CTS-1250-100
- (4) The 0.6% accuracy option is available for custom CTB Series orders
Solid-Core Current Transformers
| Solid-core CTs (toroidal) resemble donuts. To install them, the power must be turned off, the conductor disconnected, and then threaded through the CT window. Solid-core CTs are best suited for new wiring and permanent installation. |  |
| Family | Round Window | Amp Range | Accuracy(1) | Phase Angle(1) | MSRP |
|---|---|---|---|---|---|
| CTT-0300 | 0.30 in. | 5-30 A | 1.0% | < 1.0° | $32 |
| CTT-0500 | 0.50 in. | 15-60 A | 1.0% | < 1.0° | $33 |
| CTT-0750 | 0.75 in. | 30-100 A | 1.0% | < 1.0° | $35 |
| CTT-1000 | 1.00 in. | 50-200 A | 1.0% | < 1.0° | $37 |
| CTT-1250 | 1.25 in. | 70-400 A | 1.0% | < 1.0° | $43 |
- (1) The accuracy and phase angle specifications are from 10% to 100% of rated current.
Descriptions
The following sections provide brief descriptions for each series of current transformer. For full details, click on the headings.
CTM Split-Core CTsThe CTM series CTs are optimized for branch circuit monitoring. They have a hinged opening mechanism for easy installation. The small size and low cost is ideal for monitoring many circuits in a panel. | 
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Accu-CT™ ACT Split-Core CTsThe Accu-CT revenue grade, split-core current transformer offers outstanding linearity and very low phase angle error with easy one-handed opening and closing, even wearing gloves. The standard Accu-CT meets ANSI C57.13 class 1.2 and when ordered Option C0.6 it meets class 0.6 accuracy standards. Each Option C0.6 CT ships with a certificate of calibration. |  |
CTS Split-Core CTsThe CTS series CTs are available with windows from 0.75 inch up to 2.0 inch. They have a removable section, so that they can be installed without interrupting the circuit. | 
|
CTB Split-Core CTsThe CTB series CTs are designed for higher currents (up to 6000 amps) and larger conductors, including bus bars. They are available in a wider range of shapes and sizes including five stock models and almost unlimited custom variations. They have a removable section, so that they can be installed without interrupting the circuit. | 
|
CTT Solid-Core CTsThe CTT series toroidal (solid-core) current transformers do not have an opening section, so you must disconnect the measured circuit to install solid core CTs. They are better suited for new wiring or permanent installation. | 
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Safety Note
Warning: Hazardous Voltages - Only qualified personnel or licensed electricians should install the WattNode meter and current transformers.
