Intrinsically Safe VS Explosion Proof Lights
Typically, businesses don't need to spend money on explosion proof lights since they can achieve sufficient levels of safety utilising inherently safe lighting. What are the restrictions on that claim, and why is there a price difference? Two categories of lighting—intrinsically safe and explosion proof—are based on two distinct strategies for avoiding explosions in a vaporous environment.
Engineer Kevin Findlay explains the distinction as follows:
Inherent safety and explosion proof are the two most well-known types of protection. The key distinction between the two is between prevention and containment, and it's pretty significant.While allowing the ignition to take place, the containment school of thinking prevents it from spreading into the open atmosphere, where it may become deadly.Prevention keeps the source of ignition under control, never allowing enough energy to start an ignition. Utilising inherently safe equipment is by far the most representative preventative strategy.
Fundamentally Secure (IS) Standard:
The certification of light systems as inherently safe is based on international safety standards.
Products that pass their criteria in research studies receive certificates (FM3610 certification) from FM approvals, the independent testing division of worldwide insurance companies.
Standards for "Explosive Atmospheres Performance" are published by the American National Standards Institute (ANSI/ISA 60079-1 standards).
Lighting that is explosion-proof in hazardous environments is certified by United Laboratories (UL) (UL 1203)
The National Electrical Code (NEC) also offers recommendations for electricians and other professionals who install lights in dangerous places.
An inherently safe grade indicates that there is absolutely no chance of a spark starting in the equipment's wiring or electronics.
The illumination is unable to build up enough energy to ignite the gas or vapour there.
The device that powers the illumination cannot reach a surface temperature high enough to ignite the gas or vapour nearby.
Standard for explosion resistance (EP):
Lighting may not withstand an explosion even when the equipment is classified as explosion-proof. It indicates that the lighting is contained within a structure that will shield it from external explosions in the case of an internal spark.
The enclosures are often composed of cast aluminium or stainless steel.
The enclosure is intended to confine any internal explosion brought on by internal sparks if gases from a dangerous environment happen to penetrate it.
In order to comply with the requirement that, in the case of an internal explosion, the exterior surface temperature does not surpass the ignition temperature of the gases in the atmosphere, explosion-proof lighting must be suitably insulated.
Graph of hazardous environments comparing intrinsically safe and explosion-proof lights
The lighting fixtures are assessed against three recognised classes and two "divisions" of dangerous atmospheres:
Gases and vapours of Class 1 are the most explosive.
Acetylene is in Group A.
Group B. Gases comprising hydrogen produced artificially and hydrogen
Petrochemicals, Group C
Species D. Methane
Combustible dust is in Class 2.
Combustible fibres and "flyings" make up Class 3.
Within each class, there are two "divisions" of dangerous conditions:
Division I: The vapours or gases are constantly present in sufficient quantities to pose a risk of explosion.
Division II: If the gases or vapours are present, they may be concentrated enough to provide an explosive threat if present.
Low-powered lighting that frequently uses batteries and rechargeable batteries is considered intrinsically safe lighting. Light emitting diodes (LEDs), a type of low-voltage bulb, are frequently used in this illumination. This classification is frequently used for halogen torches and high-intensity discharge lights (HID).
In actuality, intrinsically safe lights are built with non-incendive electrical energy consumption limits so that sparks cannot happen at amperages and voltages that may trigger explosions in potentially dangerous environments.
An installation of a temperature sensor in a standard fixed industrial IS lighting circuit would control the amount of energy going to the light dependent on temperature. Although ambient temperature regulates the illumination, it must nevertheless adhere to strict lighting regulations.
High-intensity discharge lamps emit light through a fused quartz or fused aluminium tube that is clear, sealed, and filled with gas and metal salts. The metallic salts are heated and evaporated by an electric arc that is created in the gas, creating plasma that enhances the light produced by the arc itself. Compared to fluorescent or incandescent lights, these high-intensity lights increase the visibility of light per unit of electricity. Visible light is produced with a greater proportion of the energy than infrared (heat) energy. Over 10,000 hours of usage, the lights do deplete their fuel (metallic crystals), and their light output decreases by up to 70%.
It is generally agreed upon that intrinsically safe lighting is the best option for dangerous areas.
Low-voltage lighting fixtures are not the only devices that may be made explosion-proof. Explosion-proof gadgets have simple and well-understood wiring.
However, the cost of wiring explosion-proof lighting is high since it requires conduit, enclosures, and seals, in addition to the necessity for heavy-duty housing.
The lighting fixture's housing has to be carefully inspected for damage and leakage.
The majority of specialists concur that continual safety concerns associated with explosion-proof lights are higher since an explosion is permitted to occur and catastrophe can result if any flaws are ignored.
Devices that are intrinsically safe never even allow an ignition to start.
Even under fault settings like exposed circuit boards or damaged cables, explosions cannot occur.
Wiring is a considerably simpler technique than explosion-proof installation. It only has to be wired in accordance with the electrical code.
Devices that are intrinsically safe do not need to follow a strict maintenance schedule since there is no risk of fire. Operators are not required to leave rooms during testing and instrument programming.
Numerous hand- or portable lighting sources that run on rechargeable batteries and may be attached to low voltage A.C. are examples of intrinsically safe gadgets.
