Residual Current Monitoring Device VS Temperature-measuring Electrical Fire Monitoring Detectors

The residual current monitoring device, temperature-measuring electrical fire monitoring detector, and electrical fire control equipment can form an electrical fire monitoring system. As you know, electrical fire refers to a fire caused by short circuits, overload, and other reasons in electrical equipment. Due to the increasing popularity of electrical equipment, electrical fires have also become one of the public safety issues. For this reason, an electrical fire monitoring system came into being. The electrical fire monitoring system is suitable for various places that need to monitor electrical equipment. For some places that involve the safety of human life and property, the electrical fire monitoring system can provide timely and effective early warning for managers, thereby reducing the incidence of accidents.

Electrical fire monitoring detectors are divided into residual current electrical fire monitoring detectors (residual current monitoring device), temperature measuring electrical fire monitoring detectors, and fault arc detectors according to their working principles.

1. Residual Current Monitoring Device

Working principle of the residual current monitoring system

The Residual Current Monitoring Device can detect the current change in the electrical equipment in real-time, and monitor and warn the abnormal current. Under normal circumstances, there should be equal current in both directions in the circuit. If an electrical appliance in the circuit is short-circuited, overloaded, etc., it will cause current leakage, causing the current in the two directions of the circuit to no longer be equal. This unequal current is called “residual current”. When the residual current occurs, the residual current monitoring relay will automatically trigger the alarm device to remind personnel to deal with it quickly and avoid possible fires.

Set requirements of residual current monitoring device

(1) The residual current monitoring device should be installed at the head end of the low-voltage power distribution system as a basic principle and should be installed at the outlet end of the first-level power distribution cabinet (box). When the leakage current of the power supply line is greater than 500mA, it should be installed in the next-level power distribution cabinet (box).

(2) This dc residual current monitoring device can be installed in the distribution lines of IT systems and fire protection distribution lines.

(3) When selecting a residual current monitoring device, the influence of the natural leakage current of the power supply system should be taken into account, and a detector with appropriate parameters should be selected; the alarm value of the detector should be 300mA~500mA.

(4) For an electric fire monitor with the function of detecting line fault arcs, the length of the protective line should not be greater than 100m.

2. Temperature-measuring electrical fire monitoring detector

Working principle

The temperature-measuring electrical fire monitoring detector monitors the surface temperature of electrical equipment or electrical lines and transmits the temperature data to the controller. The controller will identify whether overheating occurs according to the preset temperature threshold. If the controller detects that the surface temperature of electrical equipment or electrical wiring exceeds a preset threshold, it will activate an alarm signal to alert operators that there may be a fire risk.

Set requirements

(1) Temperature-measuring electrical fire monitoring detectors should be installed at cable joints, terminals, key heating components, etc.

(2) The protection object is the distribution line of 1000V and below, and the temperature-measuring electrical fire monitoring detector should be arranged in a contact type.

(3) The protection object is the power supply line above 1000V. The temperature measuring type electrical fire monitoring detector should choose the grating fiber optic temperature measuring type or the infrared temperature measuring type electrical fire monitoring detector, and the grating fiber optic temperature measuring type electrical fire monitoring detector should be directly Set on the surface of the protected object.