Why Choose the ABB TR5/A Toroidal Transformer?
The ABB TR5/A is a large-aperture openable toroidal transformer for residual current monitoring, designed for use with compatible ABB earth leakage and residual current monitoring relays. As part of ABB’s Earth Monitoring Devices range, it provides the current-sensing element required to detect leakage currents in commercial and industrial low-voltage electrical installations.
The TR5/A features a 210 mm internal diameter and an openable core, allowing it to be installed around existing conductors without requiring the protected cables or busbars to be disconnected and passed through a closed toroid. This makes it particularly useful for retrofit projects, large distribution systems and installations containing substantial cable bundles.
Designed for use with compatible ABB RD and ELR residual current monitoring relays, the TR5/A provides residual current sensing across the relay’s available sensitivity settings. Its large aperture and split-core construction make it a practical solution for switchboards and industrial distribution systems where installation access and conductor dimensions make a conventional closed toroid less convenient.
Key Advantages
- 210 mm internal aperture accommodates large conductors, cable bundles and distribution applications.
- Openable core construction simplifies installation around existing conductors.
- Ideal for retrofit residual current monitoring where disconnecting conductors is impractical.
- Designed for use with compatible ABB RD and ELR residual current relays.
- IP20 protection rating for installation within suitable electrical enclosures.
- Provides reliable residual current sensing for commercial and industrial earth leakage monitoring systems.
Key Features
- ABB TR series toroidal transformer.
- 210 mm internal aperture diameter.
- Openable / split-core construction.
- Designed for residual current and earth leakage monitoring.
- Compatible with ABB RD and ELR monitoring relays.
- IP20 protection degree.
- Large aperture suitable for substantial cable groups and conductors.
- Can be fitted around existing conductors for easier retrofit installation.
- Designed for commercial and industrial low-voltage distribution systems.
- RoHS compliant according to EU Directive 2011/65/EU.
Large-Aperture Residual Current Monitoring
Toroidal transformers such as the ABB TR5/A act as the sensing element within residual current and earth leakage monitoring systems. The live conductors of the protected circuit pass through the transformer aperture and their currents normally balance. Leakage to earth creates an imbalance that the toroidal transformer detects and transmits to the connected residual current monitoring relay.
The TR5/A’s 210 mm openable core is especially useful where large conductors or multiple cables are already installed. Rather than disconnecting and feeding the conductors through a closed transformer, the openable core can be positioned around them, making the TR5/A well suited to retrofit installations, large switchboards and industrial distribution systems.
Typical Applications
- Industrial earth leakage monitoring systems.
- Large commercial electrical distribution boards.
- Electrical switchboards and control panels.
- Retrofit residual current monitoring installations.
- Large cable bundles and conductor groups requiring a 210 mm aperture.
- Residual current monitoring with compatible ABB RD and ELR relays.
