NH00CM6 Square Fuse 6A 500VAC/440VDC Equivalent & Substitute Parts

Part Overview

The NH00CM6 is a square fuse rated for 6A at 500VAC/440VDC, manufactured by Littelfuse Inc. This component is classified as obsolete, requiring identification of active equivalent parts for continued system support. The fast-blow response time and indicating feature make it suitable for motor protection applications. Due to its obsolete status, sourcing direct replacements from active product lines is necessary for maintenance and new designs.

Substiute Parts

NH00CM6

Littelfuse Inc.In Stock: 1139NH00CM6 Datasheet

Current PartRFQ

6NHG000B

Eaton - Bussmann Electrical DivisionIn Stock: 10346NHG000B Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The 6NHG000B from Eaton - Bussmann Electrical Division qualifies as a direct substitute based on the following alignment of critical parameters:

• Current Rating: Both parts rated at 6A
• Voltage Rating - AC: Both rated at 500VAC
• Fuse Type: Both are square fuses
• Response Time: Both are fast-blow
• Class: Both are NH class
• Mounting Type: Both require holder
• Approval Agency: Both carry VDE approval
• Breaking Capacity: 6NHG000B rated at 120kA AC, meeting or exceeding the main part specification

The primary difference is the DC voltage rating: NH00CM6 is rated 440VDC while 6NHG000B is rated 250VDC. This represents a reduction in maximum DC voltage capability. The 6NHG000B is suitable for applications where the DC voltage requirement does not exceed 250VDC.

Parameter Comparison

Engineering Selection Recommendations

The 6NHG000B is the qualified substitute for NH00CM6 applications where DC voltage requirements do not exceed 250VDC. Selection should be based on the following criteria:

• The 6NHG000B carries active product status, ensuring continued availability and supply chain support compared to the obsolete NH00CM6.
• The 6NHG000B is RoHS compliant, meeting current environmental and regulatory requirements, whereas NH00CM6 is non-compliant.
• Both parts maintain identical AC voltage rating (500VAC), current rating (6A), and fast-blow response characteristics required for motor protection applications.
• The reduction in DC voltage rating from 440VDC to 250VDC must be evaluated against the actual system DC voltage specification. If the application operates at or below 250VDC, the 6NHG000B is directly suitable. If the application requires 440VDC DC rating, alternative parts must be sourced.
• Both parts carry VDE approval and maintain NH class designation, ensuring compatibility with existing holder assemblies and installation infrastructure.

Frequently Asked Questions (FAQ)

Q: Can the 6NHG000B replace NH00CM6 in all applications?

A: The 6NHG000B is suitable for applications where the DC voltage requirement does not exceed 250VDC. If your system operates at 440VDC DC, the reduced DC rating of the 6NHG000B makes it unsuitable. Verify the actual DC voltage specification in your application before substitution.

Q: Are the physical dimensions compatible between these parts?

A: Both parts are square fuses requiring a holder and carry NH class designation. However, the physical dimensions differ: NH00CM6 measures 2.126" L x 2.020" W x 0.787" H, while 6NHG000B measures 2.126" L x 0.827" W x 1.693" H. Confirm that your existing fuse holder accommodates the 6NHG000B dimensions before installation.

Q: What is the significance of RoHS compliance in this substitution?

A: The 6NHG000B is RoHS compliant while NH00CM6 is not. For new designs or systems subject to RoHS regulations, the 6NHG000B meets current environmental standards. For legacy system maintenance, RoHS compliance may not be a requirement depending on your regulatory jurisdiction and application context.

Q: Do both parts have the same breaking capacity?

A: The NH00CM6 specifies 120kA AC and 25kA DC breaking capacity. The 6NHG000B specifies 120kA AC breaking capacity. Both meet the 120kA AC requirement. The DC breaking capacity difference reflects the lower DC voltage rating of the 6NHG000B.

Q: Are there any approval or certification differences?

A: Both parts carry VDE approval and are classified as NH fuses. No certification gaps exist between these parts for standard industrial and motor protection applications.