Product Overview

The XL-21 low-voltage power distribution cabinet complies with the International Electrotechnical Commission IEC 439-1 “Low-Voltage Switchgear and Controlgear Assemblies” and the national standard GB 7251-1997 “Low-Voltage Switchgear and Controlgear Assemblies.” It is suitable for power users such as power plants, substations, large-scale buildings, and office complexes. The cabinet is designed for use with AC 50 Hz and rated voltages of 500 V or lower, serving as both a power control and distribution device. The XL-21 low-voltage power distribution cabinet is an indoor installation, mounted against a wall, with maintenance accessible from the front of the enclosure. The cabinet body features excellent dust-proof characteristics, making it ideal for use in chemical plants and other dusty environments.

Structural features

1. The XL-21 low-voltage power distribution cabinet is a closed, dust-proof type. Its enclosure is fabricated from bent steel plates. The operating handle of the molded-case circuit breaker is mounted on the upper part of the right column at the front of the cabinet and can be used to switch the power supply. A voltmeter is installed on the front of the distribution box to indicate the voltage of the busbar. The front of the distribution box is equipped with a door; when the door is opened, the internal components of the distribution box are fully exposed, facilitating inspection and maintenance.

2. The XL-21 low-voltage power distribution cabinets all adopt new-type electrical components, featuring a compact structure, convenient maintenance, and flexible circuit configuration options. In addition to being equipped with air circuit breakers and fuses for short-circuit protection, these distribution boxes also offer overvoltage, undervoltage, and phase-loss alarm functions. The front door of the box can be fitted with indicator meters, operation buttons, and indicator lights.

Working conditions

(1) Altitude not exceeding 2,000 meters;

(2) The ambient air temperature shall not exceed +40℃, and the average temperature over any 24-hour period shall not exceed +35℃; the ambient air temperature shall also not fall below -5℃.

(3) Atmospheric conditions: The air shall be clean, with relative humidity not exceeding 50% at a temperature of +40℃. At lower temperatures, higher relative humidity is permissible—for example, up to 90% at +20℃.

(4) Locations free from fire hazards, explosion risks, severe contamination, chemical corrosion, and intense vibrations;

(5) During installation, the tilt angle relative to the vertical plane shall not exceed 5°.

(6) This product is suitable for transportation and storage at the following temperatures: -25℃ to +55℃. For short periods (no more than 24 hours), the temperature may not exceed +65℃.

(7) If the above-mentioned usage conditions cannot be met, the user shall notify the manufacturer at the time of ordering and negotiate a solution.

Product Parameters

Use, maintenance, and repair

After maintenance, the XL-21 low-voltage power distribution cabinet must undergo the following inspections and tests before being put into operation:

(1) Check whether the electrical components and secondary wiring inside the power distribution box comply with the requirements of the drawings.

(2) Check whether the manually operated knife switches and air switches are flexible and free of any jamming or sticking.

(3) Check whether the contacts of the installed electrical equipment are in good condition and meet the equipment’s own operational requirements.

(4) Check that there are no foreign objects inside the power distribution box, and verify that the fastening screws are not loose.