Curtis SP-600

Curtis SP-600

The Curtis SP-600 is a wall-mounted surge protector designed to plug directly into a duplex receptacle without the use of a power cord.

The documented example provides six grounded AC outlets and integrated coaxial-cable surge protection through dedicated IN and OUT connectors. Unlike many modern wall-mounted surge protectors, the SP-600 relies upon dual AC plug assemblies for mechanical retention and does not utilize the center faceplate screw commonly used by contemporary wall-hugger designs.

The documented example was purchased from Goodwill on 19 September 2026 for $5.00 and was subsequently preserved by the OldSurge Archive for documentation, testing, and analysis.

Curtis SP-600 wall-mounted surge protector documented by the OldSurge Archive.

Overview

Manufacturer	Curtis
Model	SP-600
Product Type	Wall-Mounted Surge Protector
AC Outlets	6
Coaxial Protection	Yes
Cord	None
Mounting Method	Dual Plug Assemblies
Country of Manufacture	Pending Documentation

Notable Characteristics

• First Curtis product documented by the OldSurge Archive.
• First wall-mounted surge protector documented by the archive.
• Six grounded AC outlets.
• Integrated coaxial surge protection utilizing F-type IN and OUT connectors.
• Dual-plug wall-hugger design occupying both receptacles of a standard duplex outlet.
• Does not utilize a center faceplate-retention screw.
• Green protection-status indicator window.
• Riveted enclosure construction resists non-destructive disassembly.
• U.S. Design Patent DES. 350,937.
• Designed in the USA and manufactured in China.
• 400V TVSS ratings across all protection modes.
• Purchased from Goodwill on 19 September 2026 for $5.00.

Specifications

• Width: Approximately 3.38 in (8.6 cm)
• Height: Approximately 5.13 in (13.0 cm)
• Depth: Approximately 1.25 in (3.2 cm) excluding plug assemblies

• AC Outlets: 6
• Coaxial Protection: Yes
• Coaxial Connectors: F-Type (IN / OUT)

• Electrical Rating: 15A, 120VAC, 60Hz

• Maximum Suppression Rating: 400V Peak

• TVSS Ratings:
  • H-N: 400V
  • H-G: 400V
  • N-G: 400V

• UL File: E93801
• CSA File: LR83974

• U.S. Design Patent: DES. 350,937

• Country of Manufacture: China
• Designed In: USA

Weight

The documented example weighs approximately 6.7 oz (190 g).

The relatively light weight reflects the unit's compact wall-mounted design and absence of an attached power cord.

Curtis SP-600 wall-mounted surge protector on a digital scale showing a weight of approximately 6.7 oz (190 g).

Physical Characteristics

The Curtis SP-600 utilizes a molded-plastic enclosure intended to plug directly into a standard duplex receptacle.

Six grounded outlets are arranged in two vertical rows of three receptacles each.

The lower portion of the enclosure incorporates coaxial-cable surge protection through threaded F-type connectors labeled IN and OUT.

A green indicator window is positioned near the top of the enclosure to provide operational or surge-protection status indication.

The enclosure features prominent ribbed side sections that project beyond the outlet housing and contribute to the unit's distinctive appearance.

Unlike most modern wall-mounted surge protectors, the SP-600 relies upon two complete grounded plug assemblies that occupy both receptacles of a standard duplex outlet. No provision is provided for securing the unit using the center outlet-faceplate screw.

The enclosure is assembled using metal rivets rather than screws. Complete disassembly would require destructive techniques such as drilling the rivets.

As of October 2026, the documented example has not been disassembled.

The front of the enclosure identifies the unit as SP600, while the rear data plate identifies the model as SP-600.

The enclosure is marked with U.S. Design Patent DES. 350,937.

A molded "522" marking is present on the rear of the enclosure. The significance of this marking has not been determined and it may represent a mold identifier, production code, or manufacturing reference.

Photographs

• 
  Front view showing six grounded outlets and Curtis branding.
• 
  Integrated coaxial surge-protection connectors labeled IN and OUT.
• 
  Side profile showing wall-hugger construction and cosmetic paint flecks.
• 
  Opposite side profile showing wall-hugger construction and dual-plug mounting arrangement.
• 
  Top edge showing ribbed side structure and green protection-status indicator.
• 
  Curtis branding and upper outlet row detail.
• 
  SP-600 model designation and integrated coaxial protection section.
• 
  Rear view showing dual-plug mounting arrangement and riveted enclosure construction.
• 
  Data plate showing model information, electrical ratings, certifications, patent marking, and manufacturing details.
• 
  Lower rear detail showing one plug assembly, riveted enclosure construction, and molded markings.

Condition Upon Acquisition

The documented example exhibits light cosmetic wear consistent with normal residential use.

Accumulated dirt and minor staining were visible prior to cleaning. Small paint flecks were present on one side of the enclosure and minor scuffs and handling marks were observed throughout the housing.

No evidence of melting, cracking, overheating, or major physical damage was observed during external examination.

The unit was cleaned prior to detailed photography, testing, and documentation.

Overall condition is above average for a secondhand surge protector acquired through a thrift store.

• 
  Condition upon acquisition prior to cleaning and documentation.

Functional Testing

The documented example was connected to utility power and evaluated for basic functionality.

When energized, the green status indicator illuminated, indicating that the surge protector remained powered and operational at the time of testing. Illumination was present but noticeably dim.

Testing with a receptacle tester confirmed correct hot, neutral, and ground wiring. No open-ground, open-neutral, reversed-polarity, or other wiring faults were detected.

The documented example successfully passed basic functional testing and remained operational during documentation.

• 
  Curtis SP-600 connected to utility power during testing.
• 
  Close-up view of the illuminated green status indicator during testing.
• 
  Outlet tester indicating correct wiring and grounding.

Historical References

An archived June 2001 snapshot of the Curtis website depicts related wall-mounted surge protectors identified as models SP500 and SP550.

The documented SP-600 shares a substantially similar enclosure design, outlet arrangement, indicator window, and overall construction but utilizes coaxial-cable protection connectors instead of the telephone-line protection shown on the archived models.

The archived products appeared within a "Legacy" section of the Curtis website. The significance of this designation is unknown, but it may indicate that the models represented an older or discontinued product family by June 2001.

Archived June 2001 Curtis website showing related wall-mounted surge protectors.

Archived Curtis website materials from 2001 additionally document POWER-6, POWER-7, and POWER-9 series surge protectors incorporating features such as fail-safe protection, EMI/RFI filtering, telephone-line protection, DSL and cable-modem protection, network protection, and surge-status indication.

These materials demonstrate that Curtis maintained a broad power-protection product lineup during the early 2000s.

• 
  Archived February 2001 Curtis website advertising the POWER-6 series surge protectors.
• 
  Archived February 2001 Curtis website advertising the POWER-7 series surge protectors.
• 
  Archived February 2001 Curtis website advertising the POWER-9 series surge protectors.

Collection History

The documented example was purchased from Goodwill on 19 September 2026 for $5.00 and subsequently entered the OldSurge Archive for preservation, documentation, testing, and historical research.

Documented Example

• OldSurge ID: OS-0020

Notes

• The front of the enclosure uses the model designation "SP600" while the rear data plate identifies the product as SP-600.
• The green status indicator remained functional during testing but appeared noticeably dim.
• The device remained operational during testing.
• Correct outlet wiring and grounding were confirmed using a receptacle tester.
• The documented example is currently the first and only Curtis product documented by the OldSurge Archive.
• Riveted enclosure construction prevented non-destructive internal examination.

Related Articles

• Curtis
• Surge Protectors
• Collection Index