FRS-R-4 - 4Amp Fuse

FRS-R-4 - 4Amp Fuse

When your system demands dependable protection for induction loads, motors, transformers, or lighting panels, the Eaton Bussmann FRS‑R‑4 stands out. This 4‑amp, Class RK5, dual‑element time‑delay fuse is engineered to handle transient surges without nuisance tripping—while still offering robust fault‑current interruption. Rated at 600 Vac/300 Vdc, and capable of interrupting up to 200 kA at 600 V AC and 20 kA at 300 V DC, it serves as a high‑performance safety component in demanding industrial and commercial electrical installations. With a compact 5‑inch form factor and ferrule‑end terminations for standard RK5 holders, the FRS‑R‑4 is ideal when you need high reliability, efficient installation, and long-term protection of mission‑critical circuits.

Key Features and Benefits

• Time‑Delay Dual‑Element Design: Allows for momentary inrush currents—such as motor startups or transformer energizing—without sacrificing protection.
• Current‑Limiting Technology: Reduces let‑through energy during faults, safeguarding downstream components and reducing wear on switchgear.
• Precision Engineered Form: A 5.00 inch × 0.81 inch cartridge with ferrule‑end terminations ensures fast, secure installation into standard RK5 fuse holders—minimizing downtime.
• Energy‑Efficient Operation: Maintains cooler temperatures under load and less stress during short surges, helping to lower maintenance rates and power loss.

Technical Specifications

• Catalog Number: FRS‑R‑4
• Amperage Rating: 4 A
• Voltage Rating: 600 Vac / 300 Vdc
• Interrupting Rating: 200 kA at 600 V AC; 20 kA at 300 V DC
• Response Time: 10 seconds (minimum) at 500% of rated current
• Fuse Class: RK5
• Connection Type: Ferrule end × Ferrule end (holder‑mount)
• Dimensions: Approx. 5 in (L) × 0.81 in (W) × 0.81 in (H)
• Weight: Approximately 0.13 lb (typical for this size)

Material Compliance and Certifications

• Meets UL 248‑12 and CSA C22.2 No. 248.12 for Class RK5 fuses.
• CE marked for international installations.
• RoHS‑compliant, aligning with modern environmental and sustainability initiatives.

Where It Works Best

• Ideal for protecting motor starters, HVAC systems, lighting and pump controls—especially in circuits where startup surges are expected.
• Perfect for industrial power panels, conveyor systems, and automation equipment where interruption of service due to faults must be minimized.
• When your installation calls for a time‑delay fuse capable of handling large inrush currents and still delivering high fault‑current protection, the FRS‑R‑4 is a smart choice.