Plug Comparison

Plug Comparison documents the attachment plugs used on surge protectors, power strips, relocatable power taps, UPS systems, and related power-distribution equipment preserved by the OldSurge Archive.

Although often overlooked, attachment plugs provide valuable evidence regarding manufacturing practices, component sourcing, safety standards, and product evolution. Differences in plug design can reveal changing supplier relationships, construction methods, safety requirements, and branding strategies that are not always visible elsewhere within a product.

The OldSurge Archive documents plug style, manufacturer markings, certification markings, molded date codes, grounding-pin construction, strain-relief design, and other identifying features whenever possible. Comparative examination of multiple products has revealed significant variation despite otherwise similar electrical specifications and cord construction.

Overview

Most products documented by the archive utilize North American three-prong grounding plugs conforming to the NEMA 5-15P standard.

Common variations include:

• Straight-blade plugs
• Right-angle plugs
• Branded and unbranded plugs
• Plugs incorporating molded manufacturer identification
• Plugs incorporating molded date-code wheels
• Plugs carrying independent certification markings

Although electrically interchangeable in normal use, these variations can provide useful information regarding manufacturing date, supplier relationships, safety compliance, and product positioning.

Style	Description	Typical Use
NEMA 5-15P Straight	Plug exits perpendicular to the wall surface (straight out)	Traditional surge protectors and power strips
NEMA 5-15P Right-Angle	Cord exits at 90 degrees	Furniture installations and modern surge protectors
Direct Plug	Plug integrated directly into the device with no attached cord	Wall-mounted surge protectors and outlet expanders

Documented Attachment-Plug Characteristics

Notable plug features documented by the archive include:

• Unbranded straight-blade APC plugs (1994-1996)
• APC-branded plugs (1998-2002)
• Right-angle PRO7 plugs (2015-2017)
• Belkin-branded plugs
• COXOC-branded plugs
• Globe Electric direct-plug construction
• Curtis dual-plug wall-hugger architecture
• Molded date-code wheels
• Supplier-specific certification markings

Manufacturer Branding

Some manufacturers incorporated branding directly into the plug body.

Documented examples include:

• APC
  • PRO7 (1998, 1999, 2002)

• Belkin
  • SurgeMaster F9H710-06

• COXOC
  • CO-001S
  • CO-001S Variant (OS-0030)

Many other documented products utilize unbranded attachment plugs despite otherwise extensive product branding.

Plug Evolution Within APC SurgeArrest Products

The APC SurgeArrest family provides one of the longest documented plug timelines preserved by the archive.

Documented examples include:

Model	Date	Plug Style	Notable Features
PRO7	1994	Straight	Unbranded plug body
PRO7	1996	Straight	Unbranded plug body
PRO7	1998	Straight	APC-branded plug
PRO7	1999	Straight	APC-branded plug
PRO7	2002	Straight	APC-branded plug
PRO7	2015	Right-Angle	Unbranded low-profile design
PRO7	2017	Right-Angle	Unbranded low-profile design
PER7T	2021	Straight	Well Shin plug with molded manufacturing-code wheels

The documented APC examples demonstrate a progression from unbranded straight-blade plugs during the mid-1990s through branded variants during the recall period and ultimately to later low-profile right-angle designs manufactured during the Schneider Electric era.

Molded Date Codes

Several documentated products incorporate molded manufacturing indicators within the attachment plug.

These markings commonly appear as circular code wheels molded into the rear surface of the plug body. Such markings are believed to originate from the plug manufacturer rather than the product manufacturer and likely served purposes including:

• Mold traceability
• Production tracking
• Quality control
• Manufacturing-date identification
• Tooling identification

The archive's 2021 APC SurgeArrest Personal PER7T includes two molded code wheels on the rear surface of the plug body. Similar date-wheel systems are commonly encountered on injection-molded electrical components but are not yet fully documented within the archive.

Archive Observations

Several trends have emerged through comparison of documented examples.

Nearly all corded products currently preserved by the archive utilize NEMA 5-15P grounding plugs regardless of manufacturer, age, product family, or country of manufacture. This consistency mirrors the equally widespread use of 14 AWG SJT cordage documented elsewhere in the archive.

Manufacturers frequently changed cord suppliers while retaining similar attachment-plug styles. APC's documented SurgeArrest products provide a useful example. Although Cord suppliers transitioned from Bon-Eagle and HRSA to Hi-Pro, Chung Kwang, Baohing, I-SHENG, and Well Shin over more than two decades of production, plug designs evolved more gradually and generally remained within a limited set of recognizable APC design styles.

Direct-plug products including the Curtis SP-600 and Globe Electric 12-003-7MS demonstrate alternative approaches that eliminate attached cords entirely, incorporating the wall plug directly into the device structure.

The attachment plug frequently survives even when product labels, packaging, and documentation have been lost. As a result, plug markings may provide some of the most durable surviving evidence regarding manufacturing history, supplier relationships, and product identity.

Future Research

Additional documentation may permit:

• Identification of currently unknown plug suppliers
• Correlation of molded date-code systems
• Comparison of plug manufacturing practices across brands
• Mapping of supplier changes over time
• Documentation of certification-mark evolution

Related Articles

• Power Cord Comparison
• Surge Protectors
• Power Strips
• Collection Index