Low-Voltage Current Transformers / Extended Range Current Transformers (ERCTs) for Billing, Window-Type
ROS-A Series
For 600V (max.) power systems, these current transformers offer a 0.3 Metering Class accuracy. ERCT specifications also available. Secondary side includes a short-circuiting device. Terminal cover sealable. Various window diameters and current ratios.
About the Product
Resin-insulated current transformers ROS-A Series, designed for billing purposes and suited to power systems of 600V (max.), offer revenue metering of at least a Class 0.3 Accuracy and can be used for indoor application or in an outdoor enclosure. Current Ratios available are from 100:5A to 800:5A, and window diameter options are 38mm, 66mm, and 78mm. ROS-A Series current transformers of the Standard Specifications have an RF of up to 4.0. Those of the ERCT Specifications are able to maintain the rated accuracy and burden rating while measuring 1% ~ 150% of the rated current, surpassing the usual metering-class requirement (5% ~ 100%). All ROS-A Series current transformers have been type-tested by CIC’s Advanced Electricity Lab, a testing facility accredited by a member of ILAC.
Product Features
- Standards: IEEE C57.13
- Secondary side equipped with a short-circuiting device
- Terminal cover provided for the secondary side
- Sealable
- Application: Indoors, or in an outdoor enclosure
- Rated Voltage: Up to 0.72 kV
- Frequency: 50 or 60 Hz
- 0.3 Metering Class
- Type-tested by a laboratory accredited by an ILAC member
- Additional specification or customization may be requested to comply with various electrical standards and client requirements
Selection Table
Standard Specifications
Model | Current Ratio | RF | Accuracy & Burden (IEEE) | Window Diameter | Approx. Weight | |
At 30℃ Ambient Temperature | At 55℃ Ambient Temperature | |||||
ROS-38A | 100 / 5A | 4.0 | 4.0 | 0.3 B-0.2 | 38 mm | 6.5 kg |
ROS-66A | 150 / 5A | 4.0 | 4.0 | 0.3 B-0.1 | 66 mm | 5.0 kg |
200 / 5A | 4.0 | 4.0 | 0.3 B-0.5 | |||
250 / 5A | 4.0 | 4.0 | 0.3 B-0.5 | |||
ROS-78A | 300 / 5A | 4.0 | 2.9 | 0.3 B-0.5 | 78 mm | 4.0 kg |
400 / 5A | 4.0 | 2.9 | 0.3 B-0.5 | |||
500 / 5A | 3.0 | 2.4 | 0.3 B-0.5 | |||
600 / 5A 800 / 5A | 2.0 | 1.8 | 0.3 B-0.5 | |||
2.0 | 1.5 | 0.3 B-0.5 | ||||
ERCT Specifications
| Model | Current |
| Accuracy & Burden (IEEE) | Window | Approx. |
ROS-66A | 150 / 5A | 1% ~ 150% | 0.3 B-0.1 | 66 mm | 5.0 kg |
200 / 5A | 1% ~ 150% | 0.3 B-0.5 | |||
250 / 5A | 1% ~ 150% | 0.3 B-0.5 | |||
ROS-78A | 300 / 5A | 1% ~ 150% | 0.3 B-0.5 | 78 mm | 4.0 kg |
400 / 5A | 1% ~ 150% | 0.3 B-0.5 | |||
500 / 5A | 1% ~ 150% | 0.3 B-0.5 | |||
600 / 5A | 1% ~ 150% | 0.3 B-0.5 | |||
800 / 5A | 1% ~ 150% | 0.3 B-0.5 |
Available Models
ROS-38A, ROS-66A, ROS-78A
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Used for power monitoring or as part of an MOF (Metering Outfit) for a 12~36kV power system, these outdoor CTs for billing are insulated with Araldite® UV-resistant cycloaliphatic epoxy. Accuracy 0.15S~0.3; burden B-0.5. Available as Extended Range Current Transformers (ERCTs) if requested.
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Cast in Araldite® UV-resistant cycloaliphatic epoxy resin, these medium-voltage potential transformers for billing are designed for long-term outdoor use in harsh conditions such as solar ultraviolet radiation, salt fog, high temperature, and high humidity. Designed to be part of a Metering Outfit (MOF).
- Download Materials
Low-Voltage Current Transformers or Extended Range Current Transformers (ERCT), ROS-A Series
Easy-to-print document, containing product description, specifications, and a selection table.
CT & PT Selection Guide: How to Choose a Current Transformer or Potential Transformer
How to select, based on application and power system attributes, the primary and secondary currents, burden, accuracy, rated frequency, type (indoor vs. outdoor), insulation material, etc.
