Explosion-proof Sand-filled Electronic Ballast

Introduction

This electronic ballast is designed for explosion-proof fluorescent lighting fixtures. It utilizes a two-stage architecture—combining an APFC (Active Power Factor Correction) high-power-factor circuit with an MCU-controlled PWM half-bridge resonant output circuit—to drive the fluorescent lamp. It features integrated protection circuitry for open-circuit, short-circuit, and end-of-life lamp conditions; upon triggering protection, the internal MCU program locks the system, requiring the fault to be cleared and the power to be cycled before normal operation resumes, thereby minimizing safety risks in hazardous environments. The internal circuitry and components comply with standards for sand-filled (Type "q") explosion-proof electrical equipment, with the internal cavity encapsulated in silicone potting compound. This makes the product suitable for demanding environments such as petrochemical plants, gas stations, mines, tunnels, pharmaceutical facilities, and workshops with combustible dust.

Product Features

Designed as a Class I luminaire ballast with the housing connected to the ground; a three-wire connection is required during installation. Internal insulation resistance exceeds 20 MΩ, and leakage current is less than 0.7 mA. It features independent operation for two fluorescent tubes, ensuring no mutual interference. The ballast utilizes an instant-start method without filament heating current, preventing excessive temperature buildup at the tube ends. The housing is constructed from die-cast aluminum alloy, with electrical connection points at both ends sealed with compound; it is designed as a flameproof structure capable of withstanding internal explosion pressure and preventing flame propagation. The internal electronic architecture offers superior energy efficiency compared to electromagnetic (inductive) ballasts. It ensures flicker-free operation, low noise, and stable output current, effectively extending the service life of the fluorescent tubes.

Product Performance

Open-circuit protection: Output from the corresponding ballast terminal ceases if a tube becomes disconnected.
Short-circuit protection: Output from the corresponding ballast terminal ceases if a short circuit occurs in the wiring at the tube connection.
End-of-life protection: When a tube reaches the end of its service life after prolonged operation, the rectification effect causes asymmetry in the positive and negative waveforms, resulting in a power deviation. Once this deviation reaches a specific threshold, the ballast enters protection mode and cuts off the output.

Model Information

Other specifications are available upon request.

Dimension Drawing

Unit (mm)

Wiring Diagram