ACREL Residual Current Protection Relay
ACREL Residual Current Protection Relay (ASJ20-LD1A and ASJ20-LD1C) are 48 x 48 mm residual current relays for monitoring leakage current in low-voltage distribution systems. The LD1A provides Type A residual current measurement, including sinusoidal AC and pulsating DC, while the LD1C is designed for sinusoidal AC residual current. Both models provide adjustable residual operating current and time delay, together with relay outputs and local or remote testing and resetting.
The ACREL Residual Current Protection Relay (ASJ20-LD1A and ASJ20-LD1C) is intended for applications where residual current needs to be monitored and used as part of an electrical protection arrangement. Acrel specifies the series for TT and TN distribution systems operating at AC 50 Hz and rated at 400 V or below.
The ASJ20-LD1A provides Type A residual current measurement. It detects sinusoidal alternating current as well as pulsating direct current and offers a wider adjustment range for residual operating current and non-driving time.
The ASJ20-LD1C is the Type AC version and measures sinusoidal alternating residual current. Its residual operating current can be selected from 0.03 A to 0.5 A, with selectable non-driving times of 0.1 or 0.5 seconds.
How it works
- The relay monitors residual current in the electrical circuit through the associated residual-current sensing arrangement.
- When the measured residual current reaches the configured operating level, the relay can change its output state.
- The adjustable non-driving time allows a delay to be selected before the relay operates.
- Local and remote test/reset functions are provided, with the LD1A also supporting automatic reset.
Why choose this product
- Two sensing options - choose Type A measurement with the ASJ20-LD1A or Type AC measurement with the ASJ20-LD1C.
- Adjustable protection settings - the operating residual current and time delay can be configured within the model's specified ranges.
- Compact panel format - the ASJ20 design uses a 48 x 48 mm panel format, making it suitable where panel space is limited.
- Relay interface - relay outputs can be incorporated into an external protection or control arrangement.
- Testing and resetting - local and remote test/reset functions assist with commissioning and operational checks.
Benefits
The ACREL Residual Current Protection Relay series provides a dedicated way to monitor residual current without requiring a complete protection system to be replaced. Its configurable operating thresholds allow the relay to be matched to the requirements of the installation, while the compact panel format suits electrical control panels and distribution equipment.