HY-40 Low Voltage Current Transformer for Distribution Panel Metering
The HY-40 low voltage current transformer features a 100/5A–800/5A ratio range, Class 0.5/1.0 accuracy, 1–5VA burden, and 5A output. Ideal for AC current measurement, energy monitoring, and distribution panel metering.
The HY-40 low voltage current transformer supports distribution panel metering with catalogue ratios from 100/5 A to 800/5 A and a rated 5 A secondary output. Class 1.0 is listed for all catalogue ratios; Class 0.5 options are listed at 700/5 A and 800/5 A.
Select the HY-40 by its current ratio, accuracy class, rated burden and conductor dimensions to match the measuring circuit and panel layout.
Key Features
- Rated 5 A secondary output for instruments with a matching CT input.
- Metering accuracy: Class 0.5 / Class 1.0 depending on ratio.
- Rated burden: 1-5 VA according to the selected configuration.
- Listed circular conductor opening: Ø30 mm.
- Listed busbar dimensions: 40 × 10 / 30 × 12 mm.
Technical Specifications
| Item | Specification |
| Model | HY-40 |
| Product Type | Closed-Core Low Voltage Current Transformer |
| Application | AC Current Metering and Load Monitoring |
| Rated Secondary Current | 5 A |
| Catalogued Ratio Range | 100/5-800/5 A |
| Accuracy Classes | Class 0.5 / Class 1.0 depending on ratio |
| Rated Burden | 1-5 VA according to ratio |
| Listed Busbar Dimensions | 40 × 10 / 30 × 12 mm |
| Listed Circular Opening | Ø30 mm |
Dimensions and Conductor Fit
Refer to the HY-40 dimension drawing to check the opening profile, external dimensions and installation clearance. For cables, use the outside diameter including insulation. Allow space for the CT body and secondary wiring.
Current Ratio and Rated Burden
| Current Ratio | Class 0.5 Burden | Class 1.0 Burden |
| 100/5 A | – | 1 VA |
| 200/5 A | – | 2.5 VA |
| 300/5 A | – | 2.5 VA |
| 400/5 A | – | 2.5 VA |
| 500/5 A | – | 2.5 VA |
| 600/5 A | – | 2.5 VA |
| 700/5 A | 2.5 VA | 2.5 VA |
| 800/5 A | 5 VA | 5 VA |
Typical Applications
Distribution panel metering: Connect the HY-40 to a compatible ammeter or multifunction meter for feeder current measurement. Set the instrument to the selected CT ratio.
Energy monitoring: Supply current signals to compatible energy meters for individual feeders, production areas or building distribution circuits.
Motor feeder monitoring: Observe operating current and load changes through compatible measuring equipment.
Selection and Installation
Select ratio, accuracy class and burden together. Include the instrument burden and secondary cable losses when assessing the measuring circuit. Confirm conductor fit, 5 A input compatibility and polarity before connection.
Never leave the secondary circuit open while primary current is flowing. Use an appropriate shorting arrangement before disconnecting the instrument. Protection applications require separate technical assessment.
Ordering Information
Provide the HY-40 ratio, accuracy class, rated burden, conductor dimensions and order quantity. For selection assistance, include the meter specification and secondary cable length and cross-section.
