Mersen A2K40R 250V RK1 Fuse 40 Amp

Product Description

The MERSEN A2K40R is a 40-amp, 250-volt Class RK1 current-limiting fuse designed for branch circuit and equipment protection in industrial, commercial, and HVAC applications. Class RK1 fuses provide a high degree of current limitation, reducing fault energy and protecting downstream components from damage during short-circuit events. Licensed electricians and HVAC technicians install this fuse in fusible disconnects and distribution panels where RK1 rejection-style fusing is required.

This fuse is suited for motor circuits, HVAC equipment disconnects, and general-purpose branch circuit protection rated at 250 volts AC or less. Its RK1 rejection feature prevents substitution with lower-rated fuse classes, maintaining system protection integrity. It is commonly installed in residential and light commercial service equipment, rooftop unit disconnects, and motor control panels.

Key Features

• 40-amp continuous current rating for branch circuit and load protection
• 250-volt AC voltage rating suitable for single-phase and multi-phase equipment circuits
• Class RK1 current-limiting design minimizes fault energy and protects downstream components
• Rejection-style blade configuration prevents installation of lower-performing fuse classes
• Compatible with standard RK1 fusible disconnect switches and fuse holders

Compatibility

Designed as an OEM-style replacement for Class RK1 fusible disconnect holders and distribution equipment rated at 250 volts and accepting 40-amp fuses.

Installation Notes

Installation must be performed by a licensed electrician in accordance with the National Electrical Code (NEC). De-energize and lock out the circuit before handling any fuse or fusible disconnect. Verify the replacement fuse matches the voltage and amperage rating of the original before installing. Do not substitute a non-RK1 fuse in a rejection-style holder.

Technical Specifications

• Amperage: 40 amps
• Voltage Rating: 250 volts
• Fuse Class: RK1
• UPC: 78200191513

Standard Information

• Brand: MERSEN
• Manufacturer Part Number: A2K40R