Mersen TRM4-1/2 250V Midget Time-delay Fuse 4.5A

Product Description

The MERSEN TRM4-1/2 is a 250-volt midget time-delay fuse rated at 4.5 amps, designed for overcurrent protection in control circuits, small motors, and transformer secondaries. The time-delay (TD) characteristic allows the fuse to absorb brief inrush currents without nuisance opening, while still providing fast response to sustained fault conditions. Licensed electricians and HVAC technicians install these fuses in fusible disconnect blocks, control panels, and equipment requiring UL Class CC-style midget protection. Each package contains 10 fuses.

Midget time-delay fuses in the TRM series are commonly used in residential and light commercial HVAC control circuits, low-voltage panel applications, and industrial control equipment where space-constrained fuse holders require a 13/32-inch by 1-1/2-inch body format. The 250-volt rating makes this fuse suitable for single-phase branch circuit and control wiring applications operating at standard line voltages.

Key Features

• Time-delay design absorbs motor inrush and transformer inrush without nuisance blowing
• 250-volt AC rating covers standard single-phase control and branch circuits
• 4.5-amp current rating for precise overcurrent protection in low-amperage circuits
• Midget form factor fits standard 13/32-inch by 1-1/2-inch fuse holders
• Sold in a 10-pack for service truck stocking and panel maintenance

Compatibility

Designed as an OEM-style replacement midget time-delay fuse for use in any fuse holder or disconnect block rated for 13/32-inch by 1-1/2-inch midget fuses at 250 volts or greater.

Installation Notes

Installation must be performed by a qualified electrician or licensed HVAC technician in accordance with NEC Article 240. Always de-energize and lock out the circuit before replacing a fuse. Confirm the replacement fuse matches the original amperage rating, voltage rating, and time-delay classification before reinstalling. Never substitute a higher-rated fuse to correct a nuisance-opening condition without first diagnosing the underlying fault.

Technical Specifications

• Voltage Rating: 250 volts
• Current Rating: 4.5 amps
• Fuse Type: Midget Time-Delay (TD)
• Package Quantity: 10 per pack
• Dimensions (L x W x H): 1.62 inches x 0.88 inches x 2.12 inches
• Weight: 0.13 pounds
• UPC: 78200174343

Standard Information

• Brand: MERSEN
• Manufacturer Part Number: TRM4-1/2