Carlo Gavazzi CTG120 core balance transformer with a 120 mm internal diameter and 1000/1 ratio designed for earth leakage current detection applications.
£109.95
The Carlo Gavazzi CTG120 is a high-sensitivity core balance transformer designed for detecting earth leakage currents in industrial electrical systems. As part of the Carlo Gavazzi CTG series, it detects differences in current flow through conductors passing through the transformer core and provides a secondary output signal for use with compatible residual current monitoring relays.
The CTG120 features a 120 mm internal diameter and is designed for panel mounting in industrial switchboards, electrical distribution systems and control panels where larger conductor arrangements require increased clearance. The CTG series supports both single-phase and three-phase mains applications and is approved for use with Carlo Gavazzi DEA71 and DEB71 earth leakage monitoring relays.
With a 1000/1 current transformer ratio, a 250 A nominal current rating and a 720 V AC maximum system voltage, the CTG120 provides reliable residual current detection for applications including motors, pumps and electrical equipment where earth leakage protection is required.
Core balance transformers such as the Carlo Gavazzi CTG120 detect differences between the current flowing through phase conductors and the neutral conductor. When an imbalance occurs due to leakage current, the transformer generates a secondary signal that can be processed by a residual current monitoring device to provide an alarm or protective disconnection.
The CTG series provides a practical solution for improving electrical safety in industrial installations, helping protect motors, pumps and equipment where insulation faults or leakage currents may create hazardous conditions.
| Manufacturer | Carlo Gavazzi |
|---|---|
| Series | CTG |
| Model | CTG120 |
| Product type | Core balance transformer |
| Internal diameter | 120 mm |
| Transformer ratio | 1000/1 |
| Nominal current | 250 A |
| Overload current | 1500 A |
| Short-term thermal current | 50 × In |
| Dynamic current | 2.5 × Ith |
| Frequency range | 50–60 Hz |
| Maximum system voltage | 720 V AC |
| Rated insulation level | 3 kV AC |
| Protection rating | IP20 |
| Dimensions (W × H × D) | 155 × 170 × 20 mm |
| Weight | Approx. 235 g |
| Mounting | Panel mounting with fixing flange |
| Secondary connection | Screw terminals 2 × 2.5 mm² |
| Operating temperature | -5 to +50 °C |
| Standards | IEC 61869-2 |
The CTG120 is a core balance transformer used to detect earth leakage currents by monitoring current imbalance in electrical conductors.
The Carlo Gavazzi CTG120 has a 120 mm internal diameter for routing larger monitored conductors through the transformer.
The CTG120 has a 1000/1 transformer ratio for residual current monitoring applications.
The CTG120 is designed for use with compatible Carlo Gavazzi earth leakage monitoring relays including the DEA71 and DEB71 series.
Yes, the CTG120 can be used on both single-phase and three-phase mains systems.
Carlo Gavazzi CTG core balance transformers are widely used by electrical engineers and automation professionals to improve system safety through reliable earth leakage detection and residual current monitoring.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...