Safety in the workplace is a major concern, especially if the business operates in a risky environment. Not paying adequate attention to safety can be disastrous, not only for business operations but also for workers’ lives. Hence, businesses across the world take extensive measures to ensure workplace safety.
Extra attention is paid to safety in a hazardous work environment such as an oil rig, a chemical factory or a textile mill. An area is categorized as a hazardous area when there is a presence of flammable materials such as gases, liquids, vapours, dust, fibres and other similar kinds of materials.
One of the areas where businesses put immense thought when it comes to safety, is lighting. And the two most commonly used lighting in such areas as intrinsically safe lighting and explosion-proof lighting.
Intrinsically safe lighting
As the name suggests, intrinsic safety is a method of designing equipment used in hazardous areas so that the risk of inflammation is reduced. This is done mainly in two ways:
1. Reduction of available energy to such an extent that it does not cause any ignition. This can be achieved by keeping the temperatures low and preventing sparks.
2. Design systems so that oxygen is excluded and possible sources of ignition are isolated. This can be achieved by putting equipment in strong enclosures so that the explosion can be contained. Hence the lighting equipment is fitted with a barrier. In general, two kinds of barriers are used in intrinsically safe lighting:
a. Zener barriers which have Zener diodes to divert excess energy to earth.
b. Galvanic isolators which provide isolation between the circuits between the hazardous area and safe area by using optoisolators, relays and transformers.
These low-powered lightings get their power from batteries or rechargeable batteries. They can be in the form of low-voltage bulbs, LEDs, halogen flashlights and high-intensity discharge lights. The main intention of manufacturing these lights is to reduce the chances of sparks which can cause explosions in a hazardous atmosphere.
Permanent light installations may also be fitted with an intrinsically safe device. However, such installations should have detectors/sensors with relatively low-power devices. Installations outside hazardous areas may also contain intrinsically safe barriers. These barriers limit the amount of energy available to the device located within the hazardous area.
Explosion-proof lighting, on the other hand, is more advanced in nature. Also known as Ex Lighting, in these products, the lighting fixtures are encased inside a thick glass frame so that any spark or ignition caused by the flammable materials is contained within the thick casing. The thick frame also contains complex blockages which make these light fixtures strong and durable.
The variety of lighting fixtures available in the explosion-proof category is quite high. Ex lighting can be fixed or portable and can be used in a variety of areas.
You can get an in-depth understanding of ex lighting from our following blogs:
- What is Explosion Proof Lighting?
- Types of explosion proof lighting
- Why should you use explosion proof lighting?
Intrinsically safe lighting vs explosion proof lighting
Since both these kinds of lighting are used in hazardous areas, it is important to understand the difference between the two:
Functionality: Intrinsically safe lighting limit the energy used within the circuit. Ex lighting, on the other hand, contains an explosion within the lighting fixture.
Power: In intrinsically safe lighting the entire power system is controlled and limited within a range. This limits the usage of this kind of lighting up to a specific level of power. Ex lighting has a lesser limitation of power and therefore is more versatile as compared to intrinsically safe lighting. In fact, some ex lightings are quite high powered, yet safe to be used in a hazardous area.
Wiring requirement: Intrinsically safe lighting has less complicated wiring. It usually does not contain seals or conduits. However, they require an intrinsically safe barrier. The mechanism of ex lighting is much more complex and requires seals and conduits to isolate the circuit from hazardous gases.
Maintenance: Intrinsically safe lighting can be maintained live. There is no need to shut down the system for maintenance. Ex lighting, on the other hand, cannot be serviced live. The enclosure cannot be opened while powered.
Costing: Intrinsically safe lighting is cheaper than ex lighting.
The use of intrinsically safe lighting and ex lighting is completely dependent on the grade of the hazardous area and its safety requirement. Both kinds of lights have their own functionality and are extremely useful in specific circumstances.