A fire can cause catastrophic damage to electrical systems and pose life-threatening risks. But how can you safeguard your equipment? Fire-rated enclosures offer vital protection which allows systems to function during a fire. So, this blog will cover fire resistance in enclosure materials, standards, applications, and why they are needed for safety in high-risk areas. So, let’s start!
1) What Are Fire-Rated Enclosures?
Fire rated boxes are protective boxes designed to shield electrical components from damage during a fire. These include switches, circuit breakers, wiring, and other pieces of equipment. Their primary purpose is to contain a fire, both within and outside the enclosure, long enough to maintain the equipment until it is safe to turn off systems or allow them to function continuously if necessary.
Basically, these fire rated enclosures are constructed from special materials that withstand high temperatures ( temperature range depends upon the type of material used). Some can endure fire for 30, 60, or even 120 minutes. This duration gives necessary time for emergency systems like alarms or sprinklers to activate, as well as providing time for people to leave the area safely.
The use of fire-rated enclosures is commonplace within factories, hospitals, power plants and transport systems. A fire occurring in these places can cause significant damage. Hence, it is critical to have enclosures that comply with fire safety regulations. Fire-rated enclosures are tested and certified to withstand extreme heat. They also frequently include safeguards against smoke, water, and physical impact.
2) Understanding Fire Resistance Standards
Choosing a fire rated box requires you to understand the fire resistance standards. These standards specify how well a material or enclosure can stand up to fire. They are developed by reputable companies and undergo actual testing.
So, understanding these standards allows you to purchase the right product needed to protect your electrical system in case of a fire.
Key Standards and Certifications
a) UL 94- Burns and Flame Test for Plastic Materials
UL 94 sets the framework for determining the burn characteristics of plastic substances. It indicates whether a plastic is prone to ignition, how rapidly it incinerates, and if it extinguishes on its own. Well, there are several ratings, including HB, V-2, V-1, and V-0.
- The optimum rating is V-0, which indicates that the material will extinguish within 10 seconds and will not emit flaming particles.
- In case you incorporate plastic inside your enclosure, a high UL 94 rating gives confidence that the plastic will not accelerate combustion.
b) IEC 60331-2 Static Fire Resistance of Electric Cables
This standard checks if the cables can still communicate power or signals in case of a fire outbreak. Yes! This is critical for components that need to operate during emergencies, such as fire detection systems, emergency light systems, or fire sprinkler systems.
If the cables housed within the enclosure pass this standard, they are guaranteed to remain operational for a certain duration even under severe heat conditions.
c) BS EN 50200-Madson Resistance to Fire With Mechanical Shock
This evaluation assesses the performance of cables and their enclosures under concurrent fire and mechanical stress. It guarantees your system continues functioning and avoids failure when it is stressed.
d) PH120 Rating: 120 Minutes Fire Resistance
PH means “protection of hardware.” A PH120 rating means the enclosure can protect equipment for 120 minutes during a fire. So, in areas where evacuation or fire control may take longer, it is useful.
Methods of Testing
Enclosures and materials undergo rigorous testing to receive these certifications. The following are some of the commonly accepted tests:
Tests for Vertical and Horizontal Burn
These tests assess how flames propagate along a given material. In the vertical burn test, the material hangs like drapery. Horizontally, it lies flat. These tests evaluate:
- Rate of flame propagation
- Sustained combustion of the material
- Regression of burning debris, which may readily ignite the surrounding area and spread fire
Mechanical Shock and Water Spray Tests
Some tests are not limited to fire.
- Mechanical shock tests determine the degree of impact and violent shaking a unit can sustain during a fire.
- Water spray tests demonstrate whether the unit can function normally after being drenched with water (from sprinklers/hose).
Additional testing scenarios are crucial in real-life fire situations because there is more than heat; there is movement, water, and even falling objects.
Well, when you know these standards and tests, you make better decisions. These include choosing materials that can endure extreme conditions and enclosures which will safeguard system components even under catastrophic scenarios.
3) Material Options for Fire-Resistant Enclosures
It is critical to choose the fire-rated electrical enclosure’s components with precision. The material used needs to withstand high temperatures, provide a barrier for the internal parts, and comply with safety regulations and standards. So, based on your needs, budget, and environment, there are multiple options to choose from.
i) Metals
Stainless Steel (304/316)
Stainless steel is a durable and dependable metal. It can withstand high temperatures (up to 925°C) and does not easily melt. Common Grades 304 and 316 are used. 316 is better at resisting corrosion, especially in harsh environments like coastal or chemical regions. For critical systems, you would want to use stainless steel, which offers form stability during fires.
Aluminium
Aluminium is considered to have low density compared to steel while maintaining strength. It can resist moderate heat and is often used in enclosures for indoor or low-risk areas. For example, it will lose its strength at around 200°C, and will melt at around 660°C.
Apart from this, it also has low resistance to oxidation, making it useful for humid areas. Stainless steel may outperform aluminium during extreme fires.
ii) Non-Metallic Materials
Fibreglass Reinforced Polyester (FRP)
FRP is produced by reinforcing a plastic matrix with fibreglass. It is lightweight, strong, and can sustain heat and impact. Moreover, it also has non-corrosive properties, making it useful for outdoor places.
Glass Reinforced Plastic (GRP)
Reinforced Plastic is like FRP but uses glass fibres instead of both granules and glass fabric. Well, it is strong and fire-resistant. So, it is suitable for use in industrial applications that require resistance to fire and chemicals.
FR-4 (Flame Retardant Epoxy Laminate)
WR-4 is composed of woven fibreglass cloth and epoxy resin. It’s a strong insulator, resists heat and fire. However, this material is primarily used for board circuitry but can also be applied to the parts casing.
iii) Advanced Fire-Resistant Materials
Intumescent Coatings
To be honest, this type of coating expands when heated. They provide a protective sheath to the base surface and block the quicker flow of heat. Well, these can be applied over metals, making plastics more fire resistant.
Nomex
Nomex is a flame-retardant material utilised in protective clothing. It resists melting or catching fire. Moreover, it can serve as an inner lining or barrier in enclosures.
Zetex
Zetex is a fabric made from treated fibreglass and is therefore heat-resistant. In addition, it is able to withstand extremely high temperatures and is often used in applications that require high levels of fire safety.
4) Factors Influencing Material Selection
When selecting a material for an electrical enclosure designed to be fire resistant, a multitude of factors must be taken into consideration. An appropriate fit will be determined by the environment, potential hazards, and regulations put in place for safety. Below is a summary of the critical factors to evaluate.
- Fire Resistance: The first thing to consider is how efficiently the material can resist fire. Keep in mind that the material should have passed the test, like UL 90 or should have at least a PH 120 rating. By ensuring all these, you can claim that the material will remain stable in fire.
- Environmental Conditions: Consider the location of the enclosure’s installation. Will there be exposure to rain, salt, sunlight, or chemicals? For outdoor or other extreme conditions, stainless steel or GRP are more suitable. You know these materials do not rust or degrade easily.
- Mechanical Strength: Your enclosure can be subjected to violent shocks, bumps, or extreme axial pressure. In these cases, heavy materials such as stainless steel or reinforced plastics are an absolute requirement to avoid cracks or damage.
- Corrosion Resistance: In a chemical plant, as well as coastal regions, the selected materials must resist rust as well as corrosion. Stainless Steel 316, FRP and GRP are suitable materials for these areas.
- Weight: There are times when a lighter enclosure is desired for easier handling or wall mounting. In this case, aluminium and plastic-based materials are easier and lighter compared to steel.
- Cost: Budget is always a consideration. Metals such as stainless steel are more expensive, but have a longer lifespan. On the other hand, FRP or GRP offer decent fire and weather resistance while being more economical.
- Regulatory Compliance: Various industries or regions have defined standard rules around safety. Check that the material you select is compliant with the stipulated regulations for your zone or area of work.
When you think of all these together, they help you pick the right material, which is safe, strong, and fulfils your every specific need.
5) Main advantages of Fire-Rated Enclosures
Fire-rated enclosures provide numerous benefits concerning safety, longevity, and functionality. For instance, if you work in environments prone to fires, an appropriate enclosure can play a pivotal role. Notable benefits include:
+ Improved Fire Safety: IT is clear that the biggest advantage of these enclosures is the control of fire. Fire-rated enclosures are constructed using materials that provide high-temperature resistance. These materials prevent flames from spreading while containing damage to the equipment inside. So, this helps avoid accidents and saves lives.
+ Critical Equipment Protection: During a fire outbreak, electrical systems are one of the first systems to be compromised. These enclosures help protect critical devices such as control panels, wiring, and switches. Well, this helps vital systems function for longer periods, allowing time to safely shut systems down or keep emergency systems active.
+ Extended Operation Time During Fire: Some fire-rated enclosures provide fire resistance for 30, 60 or even 120 minutes. The added time is critical for some facilities, such as hospitals and power stations, that have to remain operational during emergencies.
+ Lower Damage and Downtime: Fire-rated enclosures aid in lowering the damage caused by fire by protecting the electrical components from fire. This protects the business from paying for extra repairs and reduces the business’s downtime. After any emergencies, business operations can resume more swiftly.
+ Legal and Safety Compliance: The use of fire-rated enclosures helps companies meet legal safety obligations. Numerous enterprises need fire protection systems for tests such as UL 94 or PH120. Compliance is achieved by employing tested enclosures.
+ Assisted Insurance Claims: Having adequate systems for controlling fire hazards can improve a company’s chances of lowering its insurance claims. Moreover, it makes the coverage easier because the insurers will see that your system is all fireproof. That’s great!
+ Peace of mind: The most important benefit would be the additional assurance that comes with fire-rated enclosures. You can rest easy knowing that there is additional protection for equipment, the building, and personnel in the event of an unforeseen circumstance.
6) Applications of Fire-Rated Enclosures
Fire-rated enclosures find their purpose in many industries where fire safety is of vital importance. These enclosures safeguard electrical equipment and assist related systems in continuing to operate during fires. Let’s review some frequent use cases:
The manufacturing sector, power generation facilities, and factories often have overcrowded fire hazards due to the presence of machinery and combustible material. Industrial fire-rated enclosures safeguard control panels, wiring, and command automation systems to prevent serious accidents and damage to equipment.
A fire hazard is not uncommon in oil refineries and gas plants. These enclosures are used to enclose sensitive electrical parts and ensure that gas sensors, fire alarms, and other emergency systems function even in the case of a fire.
- Transportation Infrastructure
Fire-rated enclosures contain signal control equipment, illumination systems, and devices used for emergency communication in tunnels, railway systems and airports. These systems always remain accessible for guidance in times of crisis.
- Hospitals and Healthcare Facilities
For hospitals, an unwavering supply of life-saving equipment is required. Fire-rated enclosures secure electrical systems which activate backup power, emergency lighting, alarms, and other safety systems responsible for continuous operation during emergencies.
- Data Centres and IT Systems
As data centres require constant power and control, fire-rated enclosures guard critical power and network systems from fire, which minimises data loss or service failure.
- Commercial and Office Buildings
For large buildings, fire alarm panels and emergency lighting circuits are protected with fire-rated enclosures. They contain critical systems and help meet safety codes in protecting people inside.
Fire-rated enclosures serve to protect electrical systems from fire and corrosion damage due to hazardous chemicals, chemicals pose great fire risks in their workplaces.
These enclosures are ideal for applications where safety, performance, and fire protection are the most critical.
7) Conclusion
Fire-rated enclosures are extremely vital for protecting electrical systems from potentially devastating fire hazards while ensuring real fire resistance and critical functionality during emergency situations. Selecting materials such as metals or sophisticated materials that resist fire ensures compliance with fire safety regulations.
For best results, select fire-resistant enclosures best suited for your industry’s needs and environmental specifications. Saipwell fire-rated enclosures are made from high-quality and durable materials designed to protect systems from extreme conditions. Well, to upgrade your electrical system and to make systems safer, you can give us a chance. You can contact us right now by clicking here.
