Fuse Class H 250A NOS Series MPN:NOS-250

Fast-acting, nonindicating UL Class H and K5 fuses are for general purpose use in existing installations that require a high-sensitivity, fast-blow fuse. These fuses are highly sensitive to changes in current flow and don't tolerate temporary overload currents or power surges, so they open within seconds of being exposed to overloads and short circuits. They have no indicator for identifying a blown fuse, so they're sometimes used with an indicating fuse block or cover. Class H fuses are rated from 65A to 600A with an interrupting rating (IR) of 10kA for low-interrupt applications. Class K5 fuses are rated up to 60A with an interrupting rating (IR) of 50kA for higher interrupt applications and are current-limiting to prevent electrical damage by disconnecting circuits before they're exposed to the full magnitude and duration of an overcurrent. They're not labeled as current-limiting since they don't have a rejection feature.

UL Class H and K5 fuses are used as replacement fuses for overcurrent protection in older HVAC installations. These fuses are dimensionally the same, so they can be interchanged to change from a current-limiting system using Class K fuses to a noncurrent-limiting system using Class H fuses. Class H fuses are used in low-interrupt applications while Class K fuses have a higher interrupting rating.

Technical Specifications

• Item Fuse
• Amps 250 A
• AC Voltage Rating 600V AC
• DC Voltage Rating Not Rated
• Class H
• Series NOS
• Speed Fast Acting
• Body Style Blade
• Fits Fuse Block Style Nonrejection
• Interrupt Rating 10kA at 600V AC
• Fuse Size 11-5/8 in L x 2-19/32 in dia
• Length 11 5/8 in
• Diameter 2 19/32 in
• Equivalent Brand and Series Bussmann NOS, Littelfuse NLS, Mersen OTS
• Equivalent Series NLS, NOS, OTS
• Compatible Fuse Block Series 6HKRFB, H600, HM600, HM601, HM602, HM604
• Renewable No
• Body Material Melamine
• Element Single
• Standards CE, UL Listed, Guide JDDZ, File E4273, STD 248-6, CSA Certified Class 1421-01, File 53787

Manufacturer Details

• Manufacturer: Bussmann
• Condensed Mfg Number: NOS250
• MPN: NOS-250

Label Details

• Hazardous Material: N
• Green Material Flag: N
• Country of Origin: MX
• CA Prop 65 Wht Label: N

Classification Details

• Harmonization Code: 8536100040
• GDS Category Name: Class K5 and H Fuses
• GDS Family Name: Fuses
• GDS Segment Name: Electrical
• UNSPSC: 39121608
• UNSPSC Class ID: 16
• UNSPSC Commodity Name: Circuit protection devices and accessories
• UNSPSC Commodity ID: 08
• UNSPSC Commodity Name: Class type fuses
• UNSPSC Family ID: 12
• UNSPSC Family Name: Electrical equipment and components and supplies
• UNSPSC Segment ID: 39
• UNSPSC Segment Name: Electrical Systems and Lighting and Components and Accessories and Supplies

Shipping Details

• Not For Sale In: HI AK PR