Mersen A2K12R 250V RK1 Time-delay Fuse 12 Amp

Product Description

The MERSEN A2K12R is a 250-volt, 12-amp RK1 class time-delay fuse designed for overcurrent protection in electrical distribution systems. RK1 class fuses deliver a high degree of current limitation, making them well suited for protecting motors, transformers, and branch circuit equipment from both overload and short-circuit conditions. Licensed electricians and electrical contractors install this fuse type in industrial panels, commercial distribution boards, and HVAC equipment requiring code-compliant overcurrent protection at 250 volts AC.

This fuse is appropriate for use in 250-volt branch circuits and equipment panels where RK1 class rejection is specified. Common applications include motor branch circuit protection, HVAC unit disconnects, and control panel fusing where dual-element time-delay characteristics are required to ride through motor inrush current without nuisance opening. The A2K12R is a direct-replacement format that fits standard RK1-rated fuse holders and fusible disconnects.

Key Features

• RK1 class current-limiting design provides high short-circuit current interrupting capacity
• Time-delay element allows motor inrush current without nuisance tripping
• 250-volt AC voltage rating for single-phase and three-phase branch circuit applications
• 12-amp continuous current rating for motor and equipment protection
• Rejection-style ferrule body accepts only RK1-rated holders, preventing misapplication

Compatibility

Designed as an OEM-style replacement for RK1 class fuse holders and fusible disconnect switches rated for 250 volts AC service.

Installation Notes

Installation must be performed by a qualified, licensed electrician in accordance with the National Electrical Code (NEC). De-energize and lock out the circuit using proper lockout/tagout (LOTO) procedures before removing or installing any fuse. Use an insulated fuse puller rated for the voltage and amperage of the circuit. Verify the replacement fuse class, voltage rating, and amperage match the original equipment specification before restoring power.

Technical Specifications

• Voltage Rating: 250 volts
• Amperage Rating: 12 amps
• Fuse Class: RK1
• UPC: 78200191505

Standard Information

• Brand: MERSEN
• Manufacturer Part Number: A2K12R