ASJ10-LD1C Earth Leakage Relay

ASJ Series of action relay of after-current, low-voltage circuit break or low-voltage contactor can be made up for combined after-current production device, which is mainly applied for the TT and TN system distributing circuit with the alternating current 50Hz, the rated voltage 400V or below. ASJ Series of action relay of after-current is applied in the earth fault protection for the electric circuit, so as to prevent the equipment damage and the fire accident of electric equipment caused by the ground fault current, moreover, it also can provide indirect contact protection against the electric shock risk.

Q: How many wires can be passed through a residual current transformer?
Can I just put one firewire? Can I just pass firewire of A, B, C through the sensor?
A: In a three-phase four-wire system, 4 wires should be used. You can’t just pass a firewire, and A, B, C, N should all be passed through the Residual current transformer. A suitable transformer should be selected according to the wire diameter and rated current on site.

Q: The wire of three phase dand four wire is very thick. Can a measuring sensor be fitted to each phase, and four sensor secendary be passed through small hole size wires. Then connect the residual current relay?
A: Not recommended. By this plan, at the moment of starting the high-power and high-frequency equipment, the vector sum of the output current of three-phase four-wire measurement transformer is not zero (directly measured is 0), which can easily lead to malfunction and tripping.

Q: Can open-type residual current transformers be used in the renovation project?
A: For reconstruct projects, if the wire diameter of the line is less than 100mm, open-type residual current transformers can be used. It is not recommended to use open-type residual current transformers larger than this aperture, because the measurement accuracy of the large aperture sensor is poor.

Q: Why does the residual current relay operate as soon as it is powered on？
A: Reason one may be wiring error;  Another may be wrong product selection.

Q: After power-off the ASJ residual current relay, the breaker will trip-out. What's the reason for this phenomenon？
A: This phenomenon is that the breaker will trip-out after the protected power supply is cut off; the other is to protect the line when undergoing dual power switching.
ASJ series residual current relay is the type that automatically recovers and resets when the auxiliary power fails.According above-mentioned conditions, the instrument can be selected as the type that does not automatically act when the power fails.

Q: What does In:100A mean on the panel? Can it be removed？
A: In means rated current and cannot be removed. It is clearly stipulated in 4.2.2.2 and 5.1 of GB/T 22387-2016, the panel needs to be marked with the rated current or the size of the hole of the residual current transformer.