Compliance testing introduces significant delays to product launches, is expensive and fails to find the weak links in the designs of electrical and electronic equipment. Compliance design standards were written based on "text book" disturbance waveforms that fail to represent the real-world electrical environment. Moreover, they don't include the real-world electrical conditions that equipment must endure in the field to survive. Unfortunately, the process of obtaining certification for equipment designs does not do the design process any favors. It has become standard practice to insert "a black box" in front of the AC input to a piece of equipment to achieve the desired compliance level. However, in most cases this process doesn't work, leaving the manufacturer with an extra part to pay for and having to find a place to mount it.
If a "black box" device must be used to help an equipment design obtain compliance, the weak link in the design must be well understood and every effort to solve the immunity problem without having to use the "black box" must be made. In some cases, it is practical to use a "black box" device and in other cases, it is not. The problem with "black box" devices is that they can be removed from a product, leaving the product exposed to unfavorable electrical disturbance conditions. What happens if the "black box" device is no longer available for purchase or if the design engineer changes one of its performance metrics. Often, these types of "black box" issues don't get told to the end-use equipment engineer.
One can also take the components internal to a "black box" device and integrate them into the equipment design it self. In doing this, designers will find that the performance of the "black box" device is must better if its protection components are closer to the electronics requiring protection. Also, some of the weight of a "black box" device can be eliminated from the end-use product if the casing and wires on the add-on device can be eliminated. Moreover, the use of a "black box" device indicates that the designer of the equipment requiring protection doesn't fully understand how to protect the design and how to go about providing that protection.
Electrotek's pre-compliance testing program makes use of the largest database of electrical disturbances in the world. Smart algorithms allow expert Electrotek PQ engineers to select the disturbances known to be the most threatening to electronic equipment.
Waveforms from our Power Quality Digital Disturbance Library (PQDDL) are pre-selected and loaded into a programmable disturbance generator and injected into the equipment's power input. Test results from a host of products from one manufacturer, sometimes of similar design relative to the electronic power supply, are then used to determine the most appropriate disturbances and other critical electrical conditions to include in the product test specification. When some aspect (e.g., line voltage, load, internal electronics, etc.) of a design changes, the test is repeated to determine if the level of power quality immunity specific to that equipment design is still acceptable. If changes are needed in the test specification, then design is again evaluated for new sensitivities and sensitivities which have shifted. Then, disturbances with the right energy and frequencies known to cause malfunctions and failures are then added to the specification.