A power entry module is an electromechanical component used in electrical appliances, integrating the appliance inlet with other components such as:

• a switch, possibly including integrated or remote bowden cable
  Bowden cable
  A Bowden cable is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable relative to a hollow outer cable housing...
  
   actuation
• a circuit breaker
  Circuit breaker
  A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...
  
  , possibly including overload, overcurrent, and undercurrent protection and remote triggering
• an appliance fuse
  Fuse (electrical)
  In electronics and electrical engineering, a fuse is a type of low resistance resistor that acts as a sacrificial device to provide overcurrent protection, of either the load or source circuit...
  
   holders
• a voltage selector
• an electromagnetic interference
  Electromagnetic interference
  Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...
  
   line filter
  Line filter
  A line filter is the kind of electronic filter that is placed between an electronic equipment and a line external to it, to attenuate conducted radio frequencies -- RFI, also known as electromagnetic interference -- between the line and the equipment....
  
  
• an appliance outlet

Advantages of PEM over Individual Components:

• Compact dimensions
• Only one product with pre-wired individual components
• Efficient mounting
• Alternative designs with similar dimensions
• Protected, pre-wired and tested power components

Power entry modules are used to save labor in manufacturing electrical and electronic equipment powered by an external source, such as the AC powerline. They are also quite compact, taking up a small amount of space on the equipment’s chassis, or printed circuit board

Printed circuit board

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

.

They are designed to save labor, and frequently allow connections to the equipment circuitry using quick connect tab terminals. The AC inlet connector allows use of a separate, detachable AC line cord that has the type of wall plug favored by the locality. IEC 60320 AC inlet connectors can handle either 120 or 250 volt

Volt

The volt is the SI derived unit for electric potential, electric potential difference, and electromotive force. The volt is named in honor of the Italian physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery.- Definition :A single volt is defined as the...

s.

Since most power entry modules connect to the AC powerline, they are subject to safety standards set by Underwriters Laboratories

Underwriters Laboratories

Underwriters Laboratories Inc. is an independent product safety certification organization. Established in 1894, the company has its headquarters in Northbrook, Illinois. UL develops standards and test procedures for products, materials, components, assemblies, tools and equipment, chiefly dealing...

 (UL), the Canadian Standards Association

Canadian Standards Association

The Canadian Standards Association, also known as the CSA, is a not-for-profit Standards organization with the stated aim of developing standards for use in 57 different areas of specialisation...

 (CSA), Verband der Elektrotechnik, Elektronik und Informationstechnik

Verband der Elektrotechnik, Elektronik und Informationstechnik

The VDE Association for Electrical, Electronic and Information Technologies e.V. is one of Europe’s largest technical-scientific associations with 35,000 members, including 1,300 corporate and institutional members and 8,000 students.- Organization :...

 (VDE), and many other safety standards agencies such as BSI

BSI Group

BSI Group, also known in its home market as the British Standards Institution , is a multinational business services provider whose principal activity is the production of standards and the supply of standards-related services.- History :...

. Power entry module manufacturers take on the responsibility of producing power entry module products in such a way that they meet the standards of one or more of these safety standard agencies, so equipment manufacturers using them needn’t worry about safety issues. They also pay testing labs to test their products against the safety standards, so the products can carry the agency’s approval mark. AC Power entry modules often have dielectric strengths of 2000 volts or more, and can handle currents of up to 10 to 20 ampere

Ampere

The ampere , often shortened to amp, is the SI unit of electric current and is one of the seven SI base units. It is named after André-Marie Ampère , French mathematician and physicist, considered the father of electrodynamics...

s at 250 volts maximum. Exceeding these ratings can cause unsafe operation and must be avoided.

Medical devices can and do take advantage of power entry modules. Power entry modules are available with EMI

Electromagnetic interference

Electromagnetic interference is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source. The disturbance may interrupt, obstruct, or otherwise degrade or limit the effective performance of the circuit...

/RFI filters with very low leakage current ratings, even those suitable for direct patient contact in accordance with UL 544 and IEC 60601-1. Shock-safe fuseholders have also been integrated into power entry modules. These devices require a tool to remove the fuse for replacement.

DC power entry modules have been less common, but are finding popularity with equipment manufacturers, especially those that supply equipment in both AC- and DC-powered versions. The DC-powered versions of such equipment are frequently used in telecom central office applications.

Newer units are also available rated water resistant at IP65 with seal protection at the panel opening, around the fuse holders when provided, and between the inlet housing and connector pins.

External links

• Technical Article: What are Power Entry Modules?