Understanding NEMA Ratings & NFPA 70 Classifications

Posted on October 11, 2024 by technical

NEMA ratings and Class 1 Division 1 and 2 ratings are two different systems used to classify enclosures or areas based on their environmental and safety requirements, particularly when it comes to protection against hazards. Here’s a breakdown of each:

NEMA Ratings

NEMA (National Electrical Manufacturers Association) ratings classify electrical enclosures based on their ability to protect against various environmental conditions. These ratings focus primarily on physical protection from dust, water, and other foreign objects. Examples of NEMA ratings include:

NEMA 1: General-purpose indoor protection against dust and light.
NEMA 4: Protection against windblown dust and rain, splashing water, and hose-directed water; often used for outdoor applications.
NEMA 4X: Similar to NEMA 4, but also resistant to corrosion.
NEMA 6: Protects against occasional submersion in water.

NEMA ratings generally do not specifically address hazardous or explosive atmospheres, though some enclosures may be suitable for use in such environments depending on their design.

Class 1 Division 1 and 2 Ratings

The Class and Division system is a method used by the National Electric Code (NEC) and similar standards to describe hazardous locations where explosive or flammable gases, vapors, or dusts might be present. The focus here is on the likelihood of an explosive atmosphere being present in an area.

Class 1: Refers to locations where flammable gases or vapors are present.
Division 1: The hazardous substance (gas, vapor, or liquid) is present continuously or frequently under normal operating conditions. The risk is high, and explosive atmospheres are expected to be present.
Division 2: The hazardous substance is only present in abnormal conditions (e.g., an accidental release or equipment malfunction). The risk is lower compared to Division 1.

Class 1 Division 1 indicates a very high level of hazard since explosive or flammable gases are present most of the time. Class 1 Division 2 indicates a lower level of hazard where the risk is only during abnormal conditions.

Key Differences

Purpose:
- NEMA: Focuses on environmental protection (dust, water, corrosion).
- Class/Division: Focuses on protection from hazardous or explosive atmospheres.
Hazardous Environment:
- NEMA: Does not explicitly deal with explosive hazards.
- Class 1 Division 1 and 2: Explicitly indicates the presence of explosive gases or vapors.
Use Cases:
- NEMA: Suitable for non-hazardous areas and general protection.
- Class 1 Division 1 and 2: Required for areas where explosive or flammable substances might be present.

In short, while NEMA ratings address protection against environmental factors, Class 1 Division 1 and 2 ratings focus on the safety of equipment in areas with explosive hazards. Equipment in hazardous locations often needs to comply with both NEMA and Class/Division requirements.

NFPA 70 NEC Hazardous Locations Classes, Divisions and Groups

cLASS	DIVISION	GROUP
I – Flammable gases or vapors may be present	1 – Ignitable concentrations of hazards exist under normal operation conditions and/or where the hazard is caused by frequent maintenance or repair work or frequent equipment failure 2 – Ignitable concentrations of hazards exist under abnormal operation conditions	Group A – Acetylene Group B – hydrogen, butadiene, ethylene oxide, propylene oxide and acrolein Group C – Ethylene, cyclopropane and ethyl ether Group D – Acetone, ammonia, benzene, butane, ethanol, gasoline, hexane, methane, methanol, methane, naphtha, natural gas, propane and toluene
II – Combustible dust may be present	1 – Ignitable concentrations of hazards exist under normal operation conditions and/or where the hazard is caused by frequent maintenance or repair work or frequent equipment failure 2 – Ignitable concentrations of hazards exist under abnormal operation conditions	E – Combustible metal dusts: aluminum, commercial alloys and magnesium F – Combustible carbonaceous dusts: carbon black, charcoal, coal and coke dusts G – Other combustible dusts: Chemicals, flour, grain, plastic and wood
III – Easily ignitable fibers or flyings may be present	1 – Ignitable concentrations of hazards exist under normal operation conditions and/or where the hazard is caused by frequent maintenance or repair work or frequent equipment failure 2 – Ignitable concentrations of hazards exist under abnormal operation conditions	N/A

NFPA 70 NEC Zone Classification System

The Zone Classification System serves as an alternative to the traditional Class and Division system, offering an American adaptation of the International Electrotechnical Commission’s (IEC) Zone system. This approach retains the wiring methods and protection techniques outlined in the NEC (National Electrical Code). Zones categorize the type of hazardous material—whether gas or dust—and assess the likelihood of its presence in ignitable concentrations in the surrounding atmosphere. Unlike the Class and Division system, which focuses on normal versus abnormal conditions, the Zone system is based on how frequently the hazardous material is present.

NFPA 70 NEC Hazardous Locations Zones
Gases, Vapors and Mists	0 – Ignitable concentrations of flammable gases or vapors which are present continuously or for long periods of time
	1 – Ignitable concentrations of flammable gases or vapors which are likely to occur under normal operating conditions; may exist frequently because of repair/maintenance operations or leakage; or equipment is operated in a manner that equipment breakdown/faulty operations could result in the release of ignitable concentrations of flammable gases or vapors and failure of the equipment
	2 – Ignitable concentrations of flammable gases or vapors which are not likely to occur under normal operating conditions and if they do will only persist for a short period of time; or volatile flammable liquids, gases, or vapors are confined within closed containers/systems and can escape only as a result of an accidental rupture; or volatile flammable liquids, gases, or vapors are normally prevented by positive mechanical ventilation, but may become hazardous due to system failure
Dusts and Fibers/Flyings	20 – Combustible dusts or ignitable fibers/flyings are present continuously or for long periods of time
	21 – Combustible dusts or ignitable fibers/flyings are likely to occur under normal operating conditions; or may exist frequently because of repair/maintenance operations or leakage; or equipment is operated in a manner that breakdown/faulty operations could result in the release of ignitable concentrations of combustible dust or fibers/flyings and failure of the equipment
	22 – Combustible dusts or ignitable fibers/flyings are likely to occur under normal operating conditions; or may exist frequently because of repair/maintenance operations or leakage; or equipment is operated in a manner that breakdown/faulty operations could result in the release of ignitable concentrations of combustible dust or fibers/flyings and failure of the equipment

Group defines the type of hazardous material and partly the location of the surrounding atmosphere .

NFPA 70 NEC Hazardous Location Groups

Group I	Group II	Group III
Mines susceptible to firedamp (flammable mixture of gases naturally occurring in a mine)	Explosive gas atmospheres other than mines susceptible to firedamp – Group II equipment is subdivided into three subgroups	Explosive dusts – Group III equipment is subdivided into three subgroups
	A – Atmospheres containing acetone, ammonia, ethyl alcohol, gasoline, methane, propane, or gases/vapors of equivalent hazard	A – Atmospheres containing solid particles and fibers greater than 500 microns that could be suspended in air and settle out
	B – Atmospheres containing acetaldehyde, ethylene, or gases/vapors of equivalent hazard	B – Atmospheres containing combustible dusts other than combustible metal dusts
	C – Atmospheres containing acetylene, hydrogen, or gases/vapors of equivalent hazard	C – Atmospheres containing combustible metal dusts

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Understanding DC (Dual Circuit) Operation Types

Posted on October 8, 2024 by technical

Dual Circuit Exit Signs
Dual circuit exit signs are designed without a battery and operate using two independent power circuits, each connected directly to external power sources. These signs rely solely on these power circuits, without any internal battery backup.

Key Features:

Two Independent Power Circuits:

The exit sign is connected to two separate power circuits within the building’s electrical system.
If one circuit fails, the second circuit provides power, ensuring that the sign remains illuminated.

No Internal Battery:

Unlike traditional exit signs with a battery backup, these signs do not have a battery to provide emergency power.
The absence of a battery means that the exit sign requires a reliable secondary power source to function in case of a power failure.

Automatic Power Transfer:

The sign is designed to automatically switch to the secondary circuit if the primary circuit loses power.
This transfer happens seamlessly without the need for any manual intervention.

Dependence on Building Power Systems:

Dual circuit exit signs without batteries depend entirely on the building’s electrical infrastructure.
They are usually integrated into buildings that have emergency power systems, such as a generator, inverter systems or an uninterruptible power supply (UPS), to provide power in case of a main circuit failure.

Benefits:

Reduced Maintenance: Without a battery to maintain or replace, these exit signs require less frequent maintenance.

Cost-Effective: Eliminating the need for a battery can reduce the overall cost of the sign and maintenance expenses.

Reliable in Certain Installations: They are most effective in buildings that have robust and reliable backup power systems, such as those with emergency generators.

Limitations:

Dependence on Backup Power Systems: The exit sign will only function during a power outage if the building’s emergency power systems are operational.

Not Suitable for All Applications: In buildings without reliable emergency power, a battery-backed exit sign is often a better choice to ensure illumination.

Typical Uses:

Large Commercial Buildings: Where there is a reliable backup power supply or emergency generators.

Hospitals, Airports, and Industrial Facilities: Where a consistent and monitored emergency power system is already in place.

In summary, dual circuit exit signs without batteries are designed for environments that have dependable external emergency power systems. They provide a reliable solution without the need for battery maintenance but depend entirely on the building’s backup power infrastructure to operate during outages.

LED Drivers vs Fluorescent Ballasts

Posted on October 7, 2024 by technical

Understanding the Difference

When upgrading or designing a lighting system, it’s essential to understand the technology behind the fixtures you’re installing. Two critical components of lighting systems that often get compared are LED drivers and fluorescent ballasts. While they both serve the purpose of powering lights, they work in fundamentally different ways due to the distinct technologies they support. Let’s break down the differences to help you make more informed decisions when it comes to your lighting needs.

What is a Fluorescent Ballast?

A fluorescent ballast is an electrical device that regulates the current to fluorescent lamps. It ensures that the lamp receives the right amount of power to start and stay illuminated without consuming too much energy or burning out prematurely.

Here’s how it works:

Starting the Lamp: Fluorescent lights require a high initial voltage to ionize the gas within the tube. The ballast supplies this voltage at startup. – Current Regulation: Once the lamp is on, a ballast controls the electrical current flowing through the light. Without it, the light could draw too much current and burn out quickly.

Ballasts come in two varieties:

Magnetic Ballasts: These older types use an electromagnetic coil to regulate current, often resulting in flickering lights and audible humming. They are less energy-efficient and are being phased out in favor of more modern technology. – Electronic Ballasts: These are more efficient and use electronic components to regulate current more precisely, eliminating flickering and reducing energy consumption.

What is an LED Driver?

An LED driver is a device that regulates the power supplied to an LED (Light Emitting Diode). Unlike fluorescent lights, LEDs run on low-voltage direct current (DC), which is why an external driver is necessary to convert the high-voltage alternating current (AC) from the mains supply into the required DC voltage.

Here’s how LED drivers function:

Current Regulation: LEDs are sensitive to changes in current. Too much current can damage the diodes, while too little can cause them to underperform. The LED driver ensures the right amount of current flows through the LED to produce consistent, reliable light. – Voltage Conversion: Drivers convert high-voltage AC power from the mains to a lower voltage, typically between 2-4V DC for the LEDs.

There are two main types of LED drivers:

Constant Current Drivers: These deliver a consistent current to the LEDs, adjusting voltage as needed to maintain proper operation. – Constant Voltage Drivers: These supply a consistent voltage and rely on additional circuitry to control current.

Key Differences Between LED Drivers and Fluorescent Ballasts While both LED drivers and fluorescent ballasts regulate power, the type of lighting technology they support leads to a few fundamental differences:

Feature	Fluorescent	LED Driver
Power Conversion	Controls AC current for fluorescent lamps	Converts AC to DC for LEDs
Type of Current	Alternating Current (AC)	Direct Current (DC)
Starting Voltage	Provides a high voltage to start the lamp	No need for high starting voltage
Efficiency	Generally, less efficient	Highly efficient
Compatibility	Designed for use with fluorescent tubes	Specifically for LED lighting
Durability	Prone to flickering, lower lifespan	Long-lasting, consistent performance

Why the Difference Matters

The key takeaway is that LED drivers and fluorescent ballasts are designed for entirely different lighting technologies. Fluorescent lamps rely on ballasts to ignite and regulate the electrical current necessary for operation, while LED lights need drivers to convert power and maintain efficient performance. As lighting technology advances, LEDs are becoming the preferred option due to their energy efficiency, longevity, and overall performance, and understanding the role of LED drivers in this process is crucial.

If you’re considering an upgrade to your lighting system, transitioning to LED lighting with compatible LED drivers offers substantial long-term benefits, including lower energy costs and fewer replacements compared to traditional fluorescent lights.

Final Thoughts

Choosing between LED lighting and fluorescent lighting means understanding the crucial differences between their supporting components—LED drivers and fluorescent ballasts. While both regulate electrical flow, their application and technology differ significantly. With LEDs becoming more popular for their efficiency and performance, understanding how LED drivers work will help you ensure your lighting setup is optimized for the future.

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A Look at LiFePO4 Batteries and Some Exciting New Products from The Exit Light Co

Posted on April 23, 2024 by technical

The Exit Light Co has recently released four new products containing LiFePO4 batteries.

The EL-THO, a high-output, low-profile LED emergency light, packing a walloping 600 lumens per head. Includes a remote head capable option.
The BRAND NEW EL-SBHO, a super bright, emergency light. A powerful lighting choice with 1590 lumens. Includes a self-testing option and adjustable lamp heads.
The newest member of our stylish architectural line, the EL-DEC. This light features two operation modes: Photocell mode automatically activates the light when lighting is low and deactivates it when exposed to sufficient light. In Wall Switch mode, users can manually control the light using a switch.
We can’t forget our ever-popular weatherproof emergency light, the EL-WETLED. Two models contain the LiFePO4 battery; the cold weather unit with an internal heater and the new self-testing, high-output model.

What is a LiFePO4 battery?

LiFePO4 is a lithium-iron phosphate battery. These batteries share traits with other lithium-ion batteries with some notable differences.

Why choose LiFePO4 batteries?

Aging and Cycle-life Characteristics: LiFePO4 batteries, or LFPs, boast a significantly extended cycle life compared to other lithium-ion formulations, meaning the batteries can withstand more discharges and charges. Under typical conditions, it supports more than 3,000 cycles, and under optimal conditions, it supports more than 10,000 cycles. In comparison, NMC batteries support about 1,000 to 2,300 cycles. LFP cells also experience a slower rate of capacity loss, meaning they last longer.

Safety: Stories of exploding electrical scooters, laptop chargers igniting, and five-alarm fires have many concerned about the safety of lithium-ion batteries. LiFePo4 batteries have a different formulation and are lithium-iron phosphate batteries. This formulation is fire-safe and very resistant to overheating. These batteries are also equipped with an integrated safeguarding mechanism, referred to as a battery management system (BMS), which prevents overcharge, over-discharge, and short-circuiting.

Operational Temperature: These batteries operate at a wide range of temperatures, making them suitable for most emergency lighting applications. Generally, LiFePO4 batteries can operate at a temperature between -4°F and 140°F. Optimal performance is achieved between 32°F and 113°F. Please note: Operational temperature will depend on the specific battery and its design. It is not recommended to charge the battery when it’s at or below freezing. This will permanently damage the battery. Some batteries have internal heaters to operate in freezing temperatures.

In review, LiFePO4 batteries are a safe, reliable and longer lasting alternative to both nickel cadmium (Ni-Cd) and lithium ion (Li-Ion) batteries. As lighting and battery technologies progress, it makes for an energy efficient and safer future in life safety products.

ADA History- The Journey to Our Present

Posted on February 6, 2024 by technical

Recently, The Exit Light Co has introduced our own line of ADA signs to fill this important role in the market. Made with top quality materials and adhering to code-mandated requirements, it seemed like a natural extension of our life-safety product offering. Here is a brief history of the ADA sign.

The signing of the Americans with Disabilities Act had a dramatic impact on the lives of millions of Americans. Before its introduction, many people struggled to access basic services. Buildings, sidewalks, restrooms, and public transit proved to be difficult to navigate or, for some, completely unusable.

Section 504

The Rehabilitation Act of 1973 was the first federal civil rights protection law for people with disabilities. Section 504 prohibits discrimination against individuals with disabilities under any programs receiving federal funding. Prior to its introduction, some children were completely excluded from schools. This law has a notable impact on public education opportunities to this day. Nevertheless, many Americans still could not access businesses that serve the public such as churches, theaters, restaurants, hotels, gyms, private schools, and shops.

Americans with Disabilities Act

For decades activists fought for increased rights and to uphold those granted under 504. The ADA bill was first introduced in 1989. Activists became frustrated when the bill was stalled. On March 13, 1990 over 1,000 people marched from the White House to the U.S Capitol in protest. In a powerful display, about 60 of the participants then abandoned their wheelchairs and mobility devices to crawl up the 83 steps leading to the Capitol. This became known as the “Capitol Crawl” and helped push legislation forward. A few months later the bill was signed into law.

Our World Today

The ADA changed the way our world is built. Ramps, elevators, sidewalks, public transit, and restrooms have all been adjusted to ensure everyone has access. Public communications now include interpreters and closed captioning. This law also opened up jobs for many Americans by prohibiting discrimination against qualified individuals with disabilities in the workplace.

Today publicly accessible buildings include signs designed to help the visually impaired navigate public spaces. These signs include raised lettering, Braille, and sometimes a pictogram. They help those with and without visual impairments to locate, offices, restrooms, stairs, and much more.

Click here to see our line of ADA compliant signs.