A Power Entry Module (PEM) is a component that integrates the inlet of an appliance with other relevant components such as a switch, an EMI filter, fuse holder, circuit breaker, etc. The basic idea behind a power entry module is to combine the functions of multiple components in a single unit.
Advantages of having a Power Entry Module.
From the outside, having a power entry module might not seem like a cost-effective option. A PEM is not cheaper than the overall cost of the components that it integrates. However, it has many other advantages apart from the cost.
1. It is space saving
Since multiple components are housed together, a PEM becomes a compact unit that saves space. It also saves mounting space on panels.
2. It is safer
Typically, the power cord assembly needs to be removed before any repairs can be made to the components in the PEM. This means that there is a lower risk of electric shocks to users. Also, a PEM, as an entire unit, is made to safety standards and specifications, thus reducing the risk arising from using separate components that do not adhere to safety standards.
3. It is easier to assemble
Since a PEM combines multiple components in a single unit, there is no need to handle different components individually during assembly. This simplifies the assembly process, makes it quicker, and also brings down the labour costs.
4. It makes component management easier
Using a PEM reduces time required for purchasing individual components and also simplifies inventories. It is easier to perform testing on the assembly and recording data for monitoring.
5. It works best for companies with limited warehouse space
PEMs provide most value to small or medium size companies. Not only is installing systems easy, it is also suited for companies where warehouse space is limited. With a PEM, maintaining a stock of spare components becomes redundant.
How to choose a Power Entry Module.
Choosing a PEM for your needs depends on different factors. A few of these factors are given below.
1. Power Consumption
Both AC as well as DC power entry modules are available with DC PEMs being used in the telecommunication devices. The PEMs come with different current and voltage ratings to be used for different applications.
2. Space Consideration
PEMs save a lot of panel space. However, they do come in different sizes and the one best suited for your applications can be chosen from these. Bulgin’s Mini Bezel is a compact PEM with customizable options.
PEMs come in two mounting orientations – Horizontal and Vertical. They can be mounted on panels by quick connectors, using screws or soldering. Snap-in PEMs are easiest to install. Bulgin provides both horizontal and vertical mounting PEMs with snap-in feature. For example, the Vertical Power Entry Module 58.4mm.
4. Presence of a fuse in the PEM
Since you need a fuse to protect the other components in your circuit, a PEM with an integrated fuse is very functional. PEMs that can be switched from a single-fuse device to a double-fuse device provide most flexibility. Usually fuses for PEMs are sold separately. Care needs to be taken to buy the correct fuse which is compatible with the PEM. Vertical Power Entry Module 78.7mm from Bulgin comes with a fuse holder.
5. EMI filters & shielding
It is always best to go for PEMs that protect against EMI. EMI filters can provide protection against conductive EMI in the circuit while shields can be used to suppress radiated EMI. Horizontal Power Entry Module 95.6mm from Bulgin comes with an EMI filter.
6. Other considerations
Other considerations might include the type of switch being used and whether or not the PEM comes with a voltage selector. For example, Bulgin’s Vertical Power Entry Module 67.5mm/81.5mm comes with the option single or double pole switch. The Vertical Power Entry Module 50.8mm/78.7mm comes with a voltage selector.