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Accessory Power Systems

The key to success for any company trying to compete in the global market place is to trade its products and services with precision and ease. Markets for electrical and electronic equipment are truly global and, because of this, more competitive than ever before. In order to be successful now, it is essential to offer products that are easily adapted to the needs of global markets, without requiring reconfiguration by the user. This is especially important with regard to power cords, circuit protection and electromagnetic compatibility requirements.

Electrical plugs and sockets vary by country in size, shape, and type of connectors. Each country determines the type or types which are used and these are set by national standards legislation. With several different standard plug patterns used around the world, the problem of needing to have country specific plugs and cords can be quite daunting and expensive. In addition, many manufacturers do not have the desire or the space to warehouse or inventory all of the different cords for each different country to which their product will be exported.

A History of the Accessory Power System

According to Bob Wersen, owner and founder of Interpower, the problem was first brought to his attention in 1987. He was approached by a major electrical manufacturer for an outlet strip that could be used on a particular system they were manufacturing. The strip required specific characteristics, such as:

  • 4 IEC 60320 Sheet F outlets
  • 1 IEC 60320 C14 inlet
  • Circuit breaker for circuit protection
  • Rugged all-metal construction
  • Professional appearance
  • UL Listing, CSA Certification, VDE, or TÜV Approval

According to Wersen, the idea behind the inlet and outlet configuration was that the client wanted the entire system to utilize cord sets with the appropriate export plug in addition to an IEC60320 C13 connector that would plug in to the C14 on the accessory power strip. Jumper cords with an IEC60320 Sheet E plug on one end and an IEC 60320 C13 connector on the other would provide power to the main computer and to accessories. The only country-specific component that had to be added before shipment was the cord set. 

At that time, less expensive, plastic accessory power strips were available; however, this particular customer felt that the plastic strips lacked the quality level that was synonymous with their brand image.  In addition, these strips needed to meet agency approvals for the countries in their major markets.

Interpower began manufacturing the Accessory Power Strip almost exclusively for this client until 1990. Several other customers started specifying it for use on their equipment as well, and by 1993, sales for this item had begun to grow dramatically. 

What was apparent was that there was a real need for manufacturers worldwide to have a product that offered an easier way to design for global markets with long term cost savings. There was a great desire to be able to manufacture a product without having to worry about which plug it needed for export, if the plug was available or inventoried somewhere in the warehouse. 

Interpower has spent the last several years designing and perfecting this APS product that meets those needs. As a product designer, you can now simplify the process of designing for export in the global market. Using Accessory power systems will make it easy to build for markets all over the world because it is no longer necessary to carry several country-specific plugs and outlets. As mentioned earlier, if/when you were sending a product that required several power supply connections to different countries; you would need a country specific cord for every connection. Now, however, with the Accessory Power system, you can use one strip, jumper cords, and only ONE country specific cord. This makes it easier to build equipment that can be sold throughout the world.


There are three main reasons to use the Accessory Power system.

  1. The IEC 60320 2-2 component family makes it possible to control power to accessories through the main appliance.
  2. The IEC 60320 2-2 component system is generally accepted for use throughout the world.
  3. The use of country-specific plugs and outlets are not needed for accessory power connections. For example, it is no longer necessary to use North American plugs and outlets on peripheral equipment destined for sale in the U.S. and Canada, or British plugs and outlets on equipment destined for sale in the United Kingdom. However, the mains connection to the primary piece of equipment or the Accessory Power Strip does have to use a country specific plug.

The basic components of an accessory power distribution system are an outlet or outlets (Accessory Power Module or Strip), a power cord with a plug-connector, or a cord set with a molded plug-connector on one end and a connector on the other.

The most commonly used accessory power system is rated for use at 10A internationally and 15A in North America.

However, a second system is provided in the IEC standards with current ratings of 16A internationally and 20A in North America. See chart above for the outline drawings with the proper IEC references (see the IEC 60320 Coupler Sheet for more details).

Accessory Power Strips

Accessory Power Strips are usually specified when one of the following conditions exist:

  • The main system power will be controlled from the Accessory Power Strip.
  • The main piece of equipment in the system does not have sufficient panel space for an accessory power module.
  • The organization configuring the system is buying off-the-shelf equipment, and overall power control must be added.


Interpower Accessory Power Strips
All of the Interpower Accessory Power Strips are enclosed in an 18 gauge steel case and are intended for use with professional-quality commercial equipment. This high quality product has the VDE approval as well as approvals from the United States, Russia, Canada and Japan. All stock Accessory Power Strips include a resettable CBE (Circuit Breaker for Equipment). The complete Interpower line offers a variety of options including different housing sizes, connector locks, Sheet J outlets, switches, guards, and more.


19″ Rack-Mount Power Distribution Units

Power Distribution Units are Accessory Power Strips in a slim 1U (U or Unit is 44.45mm on which panel heights are based*) design. They fit conveniently in a standard 19″ equipment rack. Our variety of options allows control of power flow through the entire rack from the unit.

* EIA (Electronic Industries Association) -310-D.

“Universal” Jumper cords

We also offer power cords and cord sets that will allow connection between any of our Accessory Power Strips and the power mains outlet anywhere worldwide. Our standard “Universal” Jumper cords are available from stock in a variety of lengths. There is no need for overseas approval on “Universal” Jumper cords. We do not recommend country specific options on these cords. If customers try to make these items country specific, Universal cable will be eliminated.

Accessory Power Modules

For applications in which a multiple Sheet F outlet module will be mounted directly into the equipment that will control accessory power in the system, the four-position module is a cost-effective solution. This module snaps directly into a panel and is connected with a combination 1/4″ (6.3mm) quick disconnects/solder terminations. Six different panel thicknesses may be specified.

There is also an alternative that adds a C14 inlet to the four Sheet F outlets. The inlet and outlets are not electrically connected so the designer is able to specify exactly how the outlets will be controlled and protected.

Connector Locks

Connector locks secure a cord set to an IEC 60320 power inlet to prevent accidental power interruption; cord sets can be easily removed without disrupting the connector lock. Each cord set connector lock is designed for the molding of a specific cord set connector style.


Interpower Connector Locks
Interpower has models available for use with 10A and 16A IEC 60320 inlets (15A/20A North America) and are constructed of steel; black oxide finish. Click here to view our product line.


In conclusion, when looking for Accessory Power Strips (APS) you will need to consider the following:

  • Plastic vs. Metal
    • This will depend on your end user – what they want/need for durability & their budget
    • area of use – if item will be used in an area with a lot of movement it will be vulnerable and therefore, a metal APS may be best suited. If the item will simply be plugged in and “parked,” plastic would suffice.
  • Country of Export
    • You will need to make sure that the socket strips are approved for the country in which it will be shipped and used. Interpower’s APS are approved for used in the UK, US, Europe, Russia and in some cases Japan; while some APS in the market place carry only US or European approvals.

Regardless of which Accessory Power Strip you use in your designs and manufacturing process, by using an APS, you have many options to simplify things, clean up your rack systems, and/or power multiple equipment units. You can also directly affect sales by opening up opportunities for you to ship to new countries. In addition, you will save time and money by eliminating differences when shipping to different countries. Lastly, you will spread cost over more volume – yes, you will have more jumper cord sets but you will have less country specific cord sets.

If you are interested in learning more about Interpower's Accessory Power Strips, please refer to the links below which will direct you to our complete product line.


Interpower Accessory Power System

Accessory Power Strips

19″ Rack-Mount Power Distribution Units

“Universal” Jumper Cords

Accessory Power Modules


If you have any questions, please let us know by emailing