Cooper Bussmann MDL-4-R Cartridge Time Delay Fuse 4A

Product Description

The COOPER BUSSMANN MDL-4-R is a glass-body cartridge time delay fuse rated at 4 amps for use in low-voltage control circuits, instrumentation panels, and electronic equipment found in HVAC, electrical, and industrial trade applications. The time delay characteristic allows temporary inrush currents to pass without nuisance tripping while still protecting downstream components from sustained overloads and short circuits. At 1.25 inches overall length and 0.25 inches diameter, this is a standard 1/4 x 1-1/4 inch mini cartridge form factor. Interrupting ratings are 10,000 amps at 125 volts and 200 amps at 250 volts.

This fuse is suited for residential and light commercial control boards, transformer secondary circuits, and instrumentation or signal circuits where a time delay fuse is specified. Electricians and HVAC technicians commonly install this type when replacing blown fuses in control panels, zone boards, low-voltage transformer circuits, and small appliance or equipment protection applications. The glass body allows visual inspection of the fuse element without removal from the holder, which speeds up field diagnostics.

Key Features

• Time delay rating absorbs inrush current without nuisance tripping during motor or transformer startup
• Glass body enables quick visual inspection of the fuse element in the field
• 4 amp rating in a compact 0.25 inch diameter by 1.25 inch length mini cartridge form factor
• High interrupting rating: 10,000 amps at 125 volts for reliable fault protection
• RoHS compliant and UL Listed (Guide JDYX, File E19180) for use in code-required installations
• CSA and CE certified; meets MIL-STD-202 shock and vibration methods

Compatibility

Designed as an OEM-style replacement for standard 1/4 inch by 1-1/4 inch mini glass cartridge time delay fuse holders used in control circuits, instrumentation panels, and low-voltage electrical equipment.

Installation Notes

Installation is typically performed by a licensed electrician or qualified HVAC technician. De-energize and lock out the circuit before removing or installing any fuse. Verify the replacement fuse amperage, voltage rating, and time delay classification match the original specification before insertion. Do not install a fast-acting fuse in place of a time delay fuse or exceed the circuit's rated amperage.