Electronic Rack Compliance with Military Specifications
Our aluminum electronic racks are your ruggedized choice for transporting highly sensitive electronic equipment. Whether for military, aerospace or industrial applications, they provide protection against moisture, shocks, impacts, vibrations and electromagnetic interference. The racks have been designed to comply with strict military specifications including MIL-S-901D, MIL-STD-810 and MIL-STD-167.
MIL-STD-810 Testing
MIL-STD-810 is a Department of Defense Test Method Standard that ensures equipment is durable enough to withstand use in extreme environments. MIL-STD-819 testing replicates the conditions a component will experience during its service life, including low-pressure environments, humidity, shock, vibrations, and more.
Electronic racks from A&J Manufacturing follow key design and testing requirements outlined in this standard, including the following specifications:
Temperature
Products can function in operating temperatures between 32 °F and 122 °F with storage temperatures ranging from -80 °F to 160 °F. Humidity
Products can withstand 95% relative humidity without condensation. Vibration
Several configurations achieve 25-33 Hz (deck-mounted and free-standing designs). Dust and Sand
Racks provide sufficient protection from small particles such as sand and dust. Rain and Immersion
Product materials can withstand immersion in water and operate reliably in wet environments.
Altitude
Materials can withstand low-pressure conditions and sudden changes in pressure. Electronic Rack Design Considerations
Designing electronic racks that will perform reliably in some of the harshest conditions requires careful consideration of materials, structural design, and protective capabilities. At A&J Manufacturing, we work with MIL-STD-810-approved materials and develop reinforced structural designs that prevent wear or damage caused by vibrations, dust, and moisture. Read more about these key rack design considerations and features below.
- Material Selection We work with several types of aluminum alloy due to its exceptional corrosion resistance and durability. Designs that use aluminum can meet MIL-STD-810 testing requirements for dust, sand, and salt spray exposure, as well as extreme temperatures and high humidity levels.
- Vibration Resistance Racks can feature a reinforced structure to absorb any vibrations that might occur during transport or operation. Internal and external mounting systems can secure equipment within the rack and stabilize the racks themselves in airborne or shipborne environments.
- Ingress Protection Electronic enclosures must reliably protect the equipment they house from dust, sand, and moisture. They must also provide adequate ventilation to prevent sensitive equipment from overheating. Our designs feature reliable seals and gasketing with filtered ventilation to keep particulate matter out while maintaining steady airflow.
MIL-S-901D Testing
At A&J, we offer several rack configurations that adhere to MIL-S-901D standards for storing equipment on ships, including Grade A, Class 2, Type A shock requirements. MIL-S-901D outlines testing procedures for various types of shock, including:
In MIL-S-901D testing, Grade A refers to items that are essential to a ship’s safety or combat capabilities, while Grade B covers non-essential items that could still pose a safety hazard if exposed to shock. Racks meeting MIL-S-901D standards must undergo one of three testing types:
- Type A. This tests the actual structure that will be used onboard.
- Type B. This tests a component of the structure that will be used onboard.
- Type C. This involves testing components that make up larger components used onboard.
Equipment falls under one of the following classes based on the installation method:
- Class I. Equipment categorized as class one meets MIL-S-901D shock requirements without the use of resilient mountings between the equipment and the ship structure or shipboard foundation.
- Class II. Class II equipment meets the MIL-S-901D shock requirements with the use of resilient mountings between the equipment and the ship structure or shipboard foundation.
- Class III. These enclosures meet both Class I and Class II requirements, meaning they follow MIL-S-901D shock requirements with or without the use of resilient mountings.
Electronic Rack Design Considerations
At A&J Manufacturing, we consider a range of factors when designing enclosures to meet MIL-S-901D requirements. Two major factors we assess when building these enclosures are structural integrity and shock isolation. For example, creating a reliable structure might involve using heavier-gauge materials, installing cross-bracing, or reinforcing mounting points. Rack designs may also require proper weight distribution to minimize the formation of stress points during a shock event. Certain applications may require shock isolation solutions such as vibration-dampening components or specialized mounting systems.
MIL-STD-167 Testing
MIL-STD-167 testing assesses whether naval equipment will be able to endure typical operating conditions while aboard surface ships. This includes testing for mechanical vibrations as well as a range of environmental factors. Equipment testing is broken into two types: environmental and internally excited.
- Type 1 - Environmental
Type 1 assesses functional and physical integrity by subjecting equipment to vibrations in a prescribed environment. The equipment undergoes several separate tests, including:
- An exploratory vibration test
- A variable frequency test
- An endurance test
- An endurance test for all mounted equipment
- Type 2 – Internally Excited
Rotor machinery can develop internally induced vibrations, particularly if rotating components are unstable. Type 2 tests any rotating machinery for naval ships against specific balance and vibration requirements in a simulated environment.
Electronic Rack Design Considerations
A&J Manufacturing carefully assesses vibrations and numerous environmental factors when designing electronic enclosures to meet MIL-STD-167 requirements. Proper weight distribution within the rack is important to minimize the development of stress points during shock events. Equipment designs can also include reinforced frames to enhance their structural stability. Lastly, custom mounting systems and vibration-dampening solutions can provide added protection in specialized applications.
MIL-STD-461 Testing
MIL-STD-461 testing standards outline the requirements for controlling electromagnetic interference (EMI) in systems used by the Department of Defense. These standards ensure that electronic devices operate effectively in the presence of EMI and assess other factors that could potentially affect performance, including:
- Radiated Emissions. Tests the amount of electromagnetic energy emitted by equipment.
- Conducted Emissions. Sets limits on how much electrical noise can be conducted through power and signal lines.
- Radiated Susceptibility. Evaluates how well equipment can withstand external electromagnetic fields without degradation in performance.
- Conducted Susceptibility. Assesses how equipment operates when in the presence of conducted electrical noise.
Electronic Rack Design Considerations
When we build a military rack according to MIL-STD-461 standards, we take grounding, bonding, shielding, and thermal management into consideration. Using gaskets and seals in junctions and openings can improve shielding effectiveness. It’s also important to make sure the enclosure’s ventilation systems do not compromise EMI shielding capabilities. Designs can use filtered vents to allow airflow while blocking EMI.
A&J Manufacturing: Your Military & Defense Rack Experts
At A&J Manufacturing, we use our expertise to deliver high-quality electronic rack enclosures for military and defense applications. As an AS9100D and ISO 9001:2015 certified company with over 70 years of experience designing military and maritime equipment racks and enclosure solutions, A&J Manufacturing can deliver the quality products your application demands. We offer a range of design options to protect components from the effects of vibration and shock impacts, EMI, temperature changes, and more based on your exact specifications.
Contact us to learn how we can help you find the ideal product for your needs or request a quote today to start your order.
