Littelfuse SAO001 - The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.
Littelfuse

SAO001

Alternate Item Number: 0SAO001.Z

UPC: 079458400311


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Overview

The Littelfuse SAO001 Type S Adapter (SKU: SAO001) is a tamper-resistant solution designed to meet National Electric Code (NEC) requirements for Edison-base fuseholders. This adapter screws directly into existing Edison-base fuseholders, converting them to accept Type S fuses (e.g., SLO or SOO series), thereby eliminating the risk of overfusing, tampering, and nuisance fuse openings. Once installed, the SAO001 adapter cannot be removed, providing a permanent safety and compliance solution. Key specifications include a screw-in mounting type and screw connection, ensuring compatibility with standard Edison-base fuseholders. The adapter’s design prevents the installation of incorrect fuse sizes, reducing the likelihood of electrical hazards and system failures. By enforcing proper fuse ratings, the SAO001 adapter enhances system reliability and longevity, making it ideal for both retrofitting older installations and new constructions where NEC compliance is critical. The SAO001 is manufactured by Littelfuse, a trusted name in electrical protection, and is suitable for industrial, commercial, and residential applications. Pairing the adapter with Littelfuse SLO or SOO series fuses further optimizes performance and ensures consistent protection across electrical systems. This solution is particularly valuable in environments where code compliance and safety are paramount, such as manufacturing facilities, data centers, and commercial buildings. By addressing the limitations of Edison-base fuseholders, the SAO001 Type S Adapter provides a cost-effective and reliable way to upgrade existing systems without replacing entire fuseholder assemblies. Its tamper-resistant design ensures that only properly rated fuses can be installed, reducing the risk of improper maintenance and enhancing overall electrical safety.
  • Converts Edison-base fuseholders to accept Type S fuses (SLO/SOO series)
  • Tamper-resistant design prevents removal after installation
  • Meets National Electric Code (NEC) requirements for new and existing installations
  • Screw-in mounting type with screw connection for secure fit
  • Reduces risk of overfusing, tampering, and nuisance fuse openings

Specifications

Application
General purpose circuits and small motor loads
Brand Name
Littelfuse
Mounting Type
Screw-in
Series
SAO
Special Features
Feature metal threads
Sub Brand
SAO Series
Type
Plug Fuse Adapter
Package Weight (Imperial)
0.028 L
Package Weight (Metric)
0.013 kg
Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

TOO02.5

Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.
Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

TOO020

Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.
Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

TOO05.6

Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.
Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

TOO009

Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.
Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases.Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

TLO030

Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases.Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.
The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.

SAO1.25

The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.
The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.

SAO6.25

The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.
The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.

SAO020

The National Electric Code now permits Edison-base fuses to be used only for replacements in existing installations, and then, only when there is no evidence of overfusing or tampering. All new Edison-based fuseholders must have Type S fuse adapters installed before they are placed in service. Designed to prevent installation of wrong size fuses, Type S Adapters (SAO series) screw into Edison-base fuseholders so they may accept Type S fuses. Once installed the adapters cannot be removed. To prevent shunting of open fuses or overfusing, and to reduce nuisance fuse opening, it is recommended that SAO adapters with properly rated SLO or SOO series fuses be installed in all Edison-base fuseholders.
Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

TOO01.8

Littelfuse Plug fuses provide overcurrent protection to general purpose circuits and small motor loads. Edison-base Plug fuses (TOO and TLO series) feature metal threads similar to incandescent lamp bases. Type S Plug fuses (SOO and SLO series) utilize a nonmetallic threaded base and must be used with Type S adapters (SAO series). The National Electrical Code permits Edison base Plug fuses to be used for replacement purposes only. Type S fuses and adapters prevent shunting open fuses and over-fusing.

Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.