If you’re technically-minded and involved in EMC testing, then you’re probably well aware of all of the nerdy things involved in running an EMC test facility, properly outfitted with the best semi-anechoic chamber(s) and associated test equipment and cabling. To the exact letter of the law (i.e., standard), you already know how to set up and perform an accurate and repeatable radiated emissions or RF immunity scan. You know how ferrite tile and RF absorber works and which antenna(s) work best for each particular type of EMC test. You’re an expert at EMC testing but, when it comes to installing, tearing down, and moving an EMC chamber, you may not have a clear understanding of all of the non-engineering tasks that go along with such an important event.
You may be asking yourself; I’m on the technical side, why should I care about all of this non-engineering stuff? You should know that if certain items are overlooked, then a chamber install can quickly go off track and result in a non-ideal, incomplete, unusable chamber that doesn’t fully meet your EMC testing needs. Incomplete installations often require rework and result in schedule delays and cost overruns that negatively impact your company’s bottom line.
The following information points out just a few of these important considerations, which, if correctly taken into account and appropriately executed, will make the process of installing, tearing down, and moving an EMC go much more smoothly.
Installing an EMC chamber into a parent building requires interaction with various trades and other professional organizations such as architects, city administration (obtaining permits), HVAC, electrical, mechanical, and those handling life safety systems. Who is going to handle all of this effort? It is suggested that the user/buyer of the chamber (or their designee), even if they only typically work on the technical side, take on the role of chamber installation project manager. The first step that this individual can take on is that of making a list of all of the professional organizations that have an impact on the parent building and installation/moving of the chamber.
Include in the above-mentioned list, information such as contact information for the organization, who will contact them and when the actual date contact is made, what paperwork or other information is required, who will complete the paperwork, when the paperwork will be submitted, when it is required, and when it is submitted and approved. If this information is not tracked in such a detailed and organized manner, then it’s almost certain that a required permit or another important task will not get completed in time for the chamber install (or chamber move), resulting in a schedule or other harmful delay.
Power Handling Capability
This may sound obvious, but the one biggest item to make sure of at this stage of the process is that the parent building has enough power handling capability to provide the necessary power and voltage required for proper operation of the equipment under test (EUT). It would be a shame to install a chamber in a parent building only to find out at the end of the installation process that no testing can take place because of the lack of the correct power handling capability of the parent building and that installation of the correct services is a long and expensive process.
Multiple Floor Parent Buildings
The other big-ticket item to check at this stage, if a multiple story building is involved, and the chamber is intended to be installed on any floor other than the ground floor, is the floor loading. If the chamber is intended to be installed on an upper floor, then the load rating of the floor must first be determined to be adequate. Don’t wait until the chamber is on the loading dock ready to be installed to find out this information. Make sure your chamber installer is aware of this issue as soon as possible so they can provide additional guidance and resources for floor loading.
Common Problems Encountered During an EMC Chamber Installation Resulting in Delays and Cost Overruns
Below is a comprehensive list of the other often overlooked problems encountered during a chamber install, that are the sole responsibility of the user/buyer of EMC chamber:
- User/buyer asks for a revision to the drawings after they had originally given final approval. What are some reasons that the user/buyer may require a late revision to a drawing? Here are just a few examples:
- The type of penetrations and locations of the bulkheads not thoroughly thought through or specified upfront.
- The size of doorways, ramps, and other critical dimensions such as ceiling height and quiet zone size determined to be inadequate based on the size of the EUT.
- Number and types of power outlets and associated filtering for power frequency and higher RF signal frequencies are overlooked and not specified.
- Standard height loading dock not available at load/unload site.
- No arrangements prepared for the manipulation, secure staging, and secure storage of install/move equipment and chamber hardware, crating/uncrating, removal of waste material, etc.
- Forklift and forklift operator not available when needed.
- The parent room floor is not level and extra effort is required to install the chamber on a level plane.
- Housekeeping power outlets are not provided for powering installation tools.
- Services for the removal of trash and other construction debris are not provided.
- Sufficient air circulation throughout cementing and other odor-producing processes is not provided.
- Ownership of mechanical and electrical attachment between the parent building and chamber incorrectly assumed to reside with the chamber installer and not with the user/buyer.
- Access to the installation site during all necessary and available work times not provided (days, nights, weekends as required).
- Any specialty security measures at the worksite are not properly coordinated or communicated to the installation team.
- Minimum and maximum safe working temperatures are not provided.
- Worksite does not contain sufficient illumination, and other arrangements for proper lighting are required.
Other Chamber Install/Move Aspects to Consider
Consider how the chamber is to be validated at what stages of the install process validation tests need to be performed. Some validations tests to consider are:
- Shielding effectiveness (before absorber is installed)
- Normalized Site Attenuation (NSA)
- Field Uniformity (16 point per IEC 610004-3)
- Site Voltage Standing Wave Ratio (sVSWR)
- Modeled long wire absorber-lined shield enclosures (ALSE) measurement (required for automotive EMC testing)
For more information about these validation tests and others, how to perform them, and possible safety considerations that go along with them, please consult the following reference standards:
- IEEE 299 (2006) – IEEE Standard Method for Measuring the Effectiveness of Shielding Enclosures.
- ANSI C63.4-2014. American National Standard for Methods of Measurement of Radio-Noise Emissions from Low-Voltage Electrical and Electronic Equipment in the Range of 9 kHz to 40 GHz.
- CISPR 16-1-4:2010. Specification for radio disturbance and immunity measuring apparatus and methods – Part 1-4: Radio disturbance and immunity measuring apparatus – Antennas and test sites for radiated disturbance measurements.
- IEC 61000-4-3 :2006+AMD1:2007+AMD2:2010 (consolidated version). Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement techniques – Radiated, radio-frequency, electromagnetic field immunity test.
- RTCA DO-160G. Environmental Conditions and Test Procedures for Airborne Equipment (08-Dec-2010).
- CISPR 25:2016. Vehicles, boats and internal combustion engines – Radio disturbance characteristics – Limits and methods of measurement for the protection of on-board receivers.
- ISO 11452-2:2019. Road vehicles — Component test methods for electrical disturbances from narrowband radiated electromagnetic energy — Part 2: Absorber-lined shielded enclosure.