Open Frame Power Supplies

Depending on the intended use, an open frame power supply might comprise a frame without a cover, a simple chassis plate, or even just a separate PCB. The power spectrum is very broad and the design can also be customised to particular industries, such as those in the medical or manufacturing industries.

In what is recognised by the industry as an open frame format, typically AC-DC power supplies are supplied. Open frame power supply typically is defined as a device that is a build-only PCB, a part power supply to be inserted into an end application that supplies the whole product with the enclosure.

When choosing open frame power supplies or power supply open frame, there are a variety of factors, but they are essentially related to the following three main areas:

1. Safety

2. Electromagnetic Compatibility (EMC)

3. Thermal management


The required creep and clearance distances to the equipment enclosure on all faces of the supply should be observed when mounting the open frame power supply. Spacing issues will cause last-minute failure if the dimensions of the open frame power supply are not considered at the design level. Inside the equipment enclosure, installing an open frame power supply requires close consideration of clearance and creepage distances on both sides. As calculated, along with the layer of any insulation that is present, creepage refers to a path between a conductive component and the boundary of the equipment casing. Insulation can build a conductive path that can trigger a short circuit and fires can be triggered by shorts, so a good technique is to follow a gap that prevents creeping.

Electromagnetic Compatibility (EMC):

There is no enclosure on an open frame power supply which would often serve to shield electromagnetic interference. EMC control technology aims to suppress noise created by electronics, as well as protect the electronic system against external noise. For appliances or machines, input and output wiring can be mounted far apart, while still preventing location near the open frame power supply.

Thermal management:

Open frame power supplies (power supply open frame) may have a power rating when cooled by convection, air-cooled by force, or both. An open frame power supply represents compliance with requirements as-is, with no containment included facilitating heat build-up. The thermal efficiency of the power supply open frame will be influenced by several specific variables arising from the operation, such as the space around it, heat dissipation of neighboring parts, mounting location and direction, the load to be applied and the equipment cooling available.

The mounting location, accompanying space and surrounding parts are specific to each application, along with any air cooling, so it is vital to verify the working temperature of key components after they have been assembled. This guarantees that their overall scores are not exceeded by the safety-critical elements and that reliability and service life are not compromised.

Cant find the right open frame power supply? please contact us immediately, as we have direct access to product roadmap information and capability to provide bespoke solutions on a project basis. For open frame power supplies with low power or if you are looking for 3W open frame power supply or 1500W open frame power supply we can provide a solution that is right for your application.

For unrivalled technical and commercial engineering support please contact us today on 01480 412233 to see how we can help you find the perfect power conversion solution.

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