Manufacturer of fiber optic temperature monitoring system for distribution switchgear

Installation standard for temperature detection of distribution cabinets

The distribution cabinet uses fluorescent fiber optic temperature sensors, which can fully pass various inspection standards and ensure that the distribution cabinet operates within the normal temperature range.

What is the temperature of the high-voltage distribution cabinet according to the national standard? What is the normal temperature range of the distribution cabinet

1. The upper limit of air temperature around distribution boxes and cabinets shall not exceed 40 ℃;

2. The lower limit of air temperature around distribution boxes and cabinets shall not be lower than -5 ℃ or -25 ℃;

3. The average air temperature around the distribution box and distribution cabinet within 24 hours shall not exceed 35 ℃.

Temperature controller for distribution cabinet

The distribution cabinet can be installed and used with a FJINNO  fluorescent fiber optic temperature controller, which can accurately monitor the temperature of the distribution cabinet and also have functions such as alarm tripping.

The necessity of temperature monitoring system for distribution cabinet

Distribution cabinets are widely used in power plants, substations, enterprises and other power users. Due to their special purpose, the stable operation of distribution cabinets is an important guarantee for ensuring the safe use of power users.
During the use of the distribution cabinet, due to the long-term high voltage and high current working conditions of the internal contacts and busbar nodes, the resistance at the junction of the contacts and the busbar connection increases due to surface oxidation, corrosion, contact aging, and other reasons, resulting in a temperature rise and continuous accumulation of heat. This can easily lead to a gradual increase in the temperature of electronic components inside the distribution cabinet, causing electronic component failures and affecting the normal operation of the distribution cabinet. Therefore, how to adjust the temperature inside the distribution cabinet to ensure the normal operation of electronic components has become an important issue faced in the design and production of distribution cabinets.
Heating of electrical appliances in distribution cabinets is usually one of the direct causes of fire accidents. Therefore, many switches come with overcurrent thermal protection functions. However, existing switch thermal protection only detects the temperature at the inlet and outlet of the switch, while distribution cabinets usually cause heating at the terminal and busbar connection positions. The decrease in contact area at the connection position leads to an increase in resistance. When the same current flows through the heating, the temperature is much higher than in other places. When the temperature is transmitted through the busbar or cable to the switch and causes a trip, the temperature at that connection point is enough to cause a fire.
The distribution cabinet is an important equipment in the distribution system. In order to ensure the safety of the distribution cabinet, outdoor distribution cabinets are usually set up in enclosed or semi enclosed metal cabinets. This results in poor ventilation and heat dissipation performance of the distribution cabinet. However, in hot weather or under full load operation, it is easy to cause high temperature on the lines or components due to poor heat dissipation, which can easily lead to short circuits and insulation aging, affecting the normal use of the distribution cabinet and reducing its service life. At the same time, the temperature and safety monitoring of outdoor distribution cabinets usually rely on operators for inspection, which is not only inefficient but also time-consuming and laborious.

In order to increase the safety of power distribution, it is necessary to monitor the temperature inside the distribution cabinet. The conventional method for monitoring the internal temperature of the distribution cabinet is the manual inspection stage, which involves manually opening the distribution cabinet at regular intervals and using infrared temperature detectors to measure and record the temperature of the main terminals of the distribution cabinet. The main problem with this method is that manually measuring the temperature of the distribution cabinet requires opening the cabinet door, which may cause personal injury, is unsafe, and the operation is relatively complex.

The fiber optic temperature measurement system of the distribution cabinet installs fluorescent fiber optic temperature sensors at the cable inlet, busbar connection, load outlet, and inner wall of the cabinet. Based on the signals sensed by the temperature sensors at each location, they are converted into temperature values. The temperature at the inlet, busbar connection, and outlet is compared with normal temperature. If the temperature generally rises above the set value at each location, the load overload (excessive current) alarm will sound; If the temperature at a single position rises too high, the wiring will become loose (poor contact, aging of the circuit) and an alarm will be triggered; If the temperature alarm exceeds the set time, the relay output will cut off the main circuit control circuit, and the main switch will be opened for protection.

Fluorescent fiber optic temperature sensors can also be installed inside the distribution cabinet near the bottom, near the top, and between other temperature sensors. They can accurately measure the temperature of various parts inside the distribution cabinet, avoiding false alarms caused by local overheating when only one set of temperature sensors is used. The internal temperature monitoring of the distribution cabinet is more accurate. At the same time, the setting of three sets of temperature sensors can accurately measure areas with temperature anomalies. When local temperatures become overheated due to component failures in government departments, the fault anomaly channel can be clearly displayed, providing a location reference for the maintenance of electronic components inside the distribution cabinet. Moreover, the display module includes indicator lights, which can visually determine the temperature status of the distribution cabinet. Communication modules can also be customized to facilitate the export of internal monitoring data in the distribution cabinet, which is beneficial for long-term monitoring of the working status of the distribution cabinet and improves the reliability of its application.