Intrinsic Safety – IAEI Magazine (2023)

Intrinsic safety is the method of protection for control and instrumentation circuits where the nominal voltage is 24 VDC or less and the current is normally less than 100 mA. The concept of intrinsic safety is to limit the voltage and current so that there is never a spark with enough energy to create an explosion. Intrinsic safety when properly used removes the ignition from the explosion triangle.

There are three components to an intrinsically safe circuit: the field device, intrinsically safe barrier and field wiring.

  • Field devices known as intrinsically safe apparatus are classified as simple or complex.
  • Simple apparatus, which do not need to be approved, are non-energy storing devices such as contacts, thermocouples, RTDs, LEDs and resistors.
  • Complex apparatus such as transmitters, solenoids, relays and transducers may store excess energy and need to be approved by a third party.
  • Contacts, transmitters and temperature sensors are the most commonly used field devices in intrinsically safe applications.
  • The intrinsically safe barrier limits the current with a resistor and the voltage with a zener diode.
  • Intrinsically safe circuits are designed so that they operate properly under normal conditions, but keep the energy levels below the ignition curves when a fault condition occurs.

Three components to a barrier limit current and voltage: a resistor, at least two zener diodes, and a fuse. The resistor limits the current to a specific value known as the short-circuit current(Isc). The zener diode limits the voltage to a value referred to as open-circuit voltage (Voc). The fuse will blow when the diode conducts. This interrupts the circuit, which prevents the diode from burning and allowing excess voltage to reach the hazardous area. There always are at least two zener diodes in parallel in each intrinsically safe barrier. If one diode should fail, the other will operate providing complete protection.

Intrinsic Safety – IAEI Magazine (1)

Photo 1. Cooper Crouse-Hinds offers grounded and isolated intrinsically safe barriers in addition to intrinsically safe remote I/O.

Intrinsic Safety – IAEI Magazine (2)

Figure 1. Barrier circuit with an intrinsically safe barrier

A simple analogy is a restriction in a water pipe with an overpressure shutoff valve. The restriction prevents too much water from flowing through the point, just like the resistor in the barrier limits current. If too much pressure builds up behind the restriction, the overpressure shutoff valve turns off all the flow in the pipe. This is similar to what the zener diode and fuse do with excess voltage. If the input voltage exceeds the allowable limit, the diode shorts the input voltage to ground and the fuse blows, shutting off electrical power to the hazardous area.

Determining Safe Energy Levels

Intrinsic Safety – IAEI Magazine (3)

Figure 2. If the energy level of a typical thermocouple circuit were plotted on the ignition curve in figure 2, it would not be close to the ignition levels of the most volatile gases in Group A.

Voltage and current limitations are ascertained by ignition curves, as seen in figure 4. A circuit with a combination of 30 V and 150 mA would fall on the ignition level of gases in Group A. This combination of voltage and current could create a spark large enough to ignite the mixture of gases and oxygen. Intrinsically safe applications always stay below these curves where the operating level of energy is about 1 watt or less. There also are capacitance and inductance curves which must be examined in intrinsically safe circuits. [See figure 1]

Consider the ignition curves to demonstrate a point about thermocouples. A thermocouple is classified as a simple device. It will not create or store enough energy to ignite any mixture of volatile gases. If the energy level of a typical thermocouple circuit were plotted on the ignition curve in figure 2, it would not be close to the ignition levels of the most volatile gases in Group A. Is the thermocouple which is installed in a hazardous area (see figure 3) intrinsically safe? The answer is no, because a fault could occur on the recorder which could cause excess energy to reach the hazardous area, as seen in figure 4. To make sure that the circuit remains intrinsically safe, a barrier to limit the energy must be inserted (see figure 5).

Approvals—Start with the Field Device

Intrinsic Safety – IAEI Magazine (4)

Figure 3. Is the thermocouple which is installed in a hazardous area (see figure 3) intrinsically safe? The answer is no, because a fault could occur on the recorder which could cause excess energy to reach the hazardous area, as seen in figure 4.

All intrinsically safe circuits have three components: the field device referred to as the intrinsically safe apparatus, the energy-limiting device also known as the barrier or intrinsically safe associated apparatus, and the field wiring. The design of the intrinsically safe circuit begins with the analysis of the field device. This will determine the type of barrier that can be used so that the circuit functions properly under normal operating conditions but is still safe under fault conditions.

(Video) AI Ethics: Global Perspectives Panel #5 – June 22, 2021

Intrinsic Safety – IAEI Magazine (5)

Figure 4. A fault could occur on the recorder which could cause excess energy to reach the hazardous area

An intrinsically safe apparatus (field device) is classified either as a simple or non-simple device. Simple apparatus is defined in paragraph 3.12 of the ANSI/ISA-RP12 12.6-1987 as any device which will neither generate nor store more than 1.2 volts, 0.1 amps, 25 mW or 20 µJ. Examples are simple contacts, thermocouples, RTDs, LEDs, nonincendive potentiometers and resistors. These simple devices do not need to be listed as intrinsically safe (see 504.4, Exception). If they are connected to an approved intrinsically safe apparatus (barrier), the circuit is considered intrinsically safe.

Intrinsic Safety – IAEI Magazine (6)

Figure 5. To make sure that the circuit remains intrinsically safe, a barrier to limit the energy must be inserted

A non-simple device can create or store levels of energy that exceed those listed above. Typical examples are transmitters, transducers, solenoid valves, and relays. When these devices are approved as intrinsically safe, under the entity concept, they have the following entity parameters: Vmax (maximum voltage allowed); Imax (maximum current allowed); Ci (internal capacitance) and Li (internal inductance).

The Vmax and Imax values are straightforward. Under a fault condition, excess voltage or current could be transferred to the intrinsically safe apparatus (field device). If the voltage or current exceeds the apparatus Vmax or Imax, the device can heat up or spark and ignite the gases in the hazardous area. The Ci and Li values describe the devices’ ability to store energy in the form of internal capacitance and internal inductance. [See photos 1, 2, and 3]

Limiting Energy to the Field Device

Intrinsic Safety – IAEI Magazine (7)

Photo 2. Terminal boxes and conduits carrying intrinsically safe circuits must be separated from all other wiring and properly labeled.

To protect the intrinsically safe apparatus in a hazardous area, an energy-limiting device (barrier) must be installed. Under normal conditions, the device allows the intrinsically safe apparatus to function properly. Under fault conditions, it protects the field circuit by preventing excess voltage and current from reaching the hazardous area. When conducting the safety analysis or inspection of the circuit, it is important to compare the entity values of the intrinsically safe apparatus against the associated apparatus. These parameters usually are found on the product or in the control-wiring diagram from the manufacturer.

Intrinsically Safe Barriers

Three types of barriers are most commonly used:

1. Zener barriers—passive devices which required grounding for safety

2. Isolation barriers—do not require grounding and contain additional electronics for isolation and signal conditioning, or

3. Ex-ia I/O—combines I/O with intrinsic safety into one package.

Grounded Zener Barriers

Intrinsic Safety – IAEI Magazine (8)

Photo 3. Intrinsically safe circuits can be worked on while live without danger of creating sparks with enough energy to cause ignition.

Grounded barriers, also referred to as zener barriers, are passive devices which contain zener diodes to limit excess voltage, resistors to limit current and fuses. These are the basic building blocks which are contained in all other intrinsically safe barriers. There is always a voltage drop across grounded barriers because of the resistors so some selection is required as well as a ground connection. This selection has been greatly simplified in recent years as manufacturers make them more application specific. Grounded barriers are also very versatile and can be applied in many other applications. If your application has less than 20 outputs or inputs and grounding is not a consideration, this may be the best solution.

DIN Rail Grounded Barriers

Advantages include:

  • lowest initial cost per unit;
  • very small < 1/2″ wide;
  • very precise signal response;
  • small power requirements; and
  • versatile for “other” circuits.

Other considerations include:

  • requires ground; and
  • barrier resistance can influence circuit function.

Isolation Barriers

Intrinsic Safety – IAEI Magazine (9)

Figure 6. The intrinsically safe conductors must be separated from all other wiring by placing them in separate conduits or by a separation of a minimum of 2 inches of air space.

DIN rail isolated barriers, also referred to as transformer-isolated or galvanically-isolated barriers, are zener barriers with additional electronics to isolate and condition the signals. Adding the isolation has the advantage that an intrinsically safe-ground connection is not required. The signal conditioning of isolated barriers simplifies the selection process as each isolated barrier is manufactured for specific functions such as switching, temperature measurements or 4-20 mA readings. These isolated units are ideal for digital inputs or for OEMs where grounding may cause problems at the local installation.

Din Rail Isolated Barriers

Advantages include:

  • does not require IS ground;
  • loop layout and barrier selection is easier; and
  • integrated signal conditioning.

Other considerations include:

  • higher cost than grounded barriers;
  • larger width ˜1″” wide; and
  • larger power requirements.

Remove I/O Products

Intrinsic Safety – IAEI Magazine (10)

Table 1

Until recently there were limited improvements made in this industry. The latest generation of products now reduce the total installed cost by combining the intrinsically safe barriers with the I/O eliminating extra hardware. These new systems called intrinsically safe remote I/O can be mounted almost anywhere in hazardous or ordinary locations reducing the wiring and terminations. These systems were initially designed for the German Chemical industry which wanted to reduce installation costs and no longer had enough space in control rooms to house termination panels. Their reasoning was to extend the 2-wire communication lines out as far away as possible in the process area to minimize field wiring to the sensors and extra termination cabinets.

Signals to and from the hazardous area are made intrinsically safe, processed by the remote I/O electronics, and transmitted to a memory module through a communication link that is normally mounted on the backplane, which holds the electronics. These signals are updated every 5 milliseconds and stored for pickup and transport to the main control system. The intrinsically safe remote I/O system is connected to the controller by a simple 2-wire or fiber optic link to relay information back and forth.

These systems are ideal for users, who want to eliminate wiring from the control system to the I/O and can communicate via a bus system such as Modbus, Profibus, or Fieldbus.

Intrinsically Safe Remote I/O Systems

Advantages include:

  • lowest installed cost (40 percent savings);
  • uses digital communications for more accurate and faster readings;
  • easy product selection;
  • least amount of wiring;
  • no ground required; and
  • easiest add-on for future.

Other considerations include:

  • some expertise required in “systems.”

Remember the keys to intrinsic safety are:

  • it is used only on instrumentation and control circuits that operate on 24 volts or less;
  • it is not used on power circuits of 30 volts and definitely not 120 volts and above;
  • it is used in Division 1 and Zones 0 and 1 areas; and
  • intrinsic safety barriers prevent ignition of volatile gases and dusts by limiting the voltage and current into hazardous areas.

Three solutions depend on the number of devices that need to be protected in the hazardous area ranging from simple passive devices which require grounding, isolated devices which do not need a ground, and the intrinsically safe remote I/O which eliminates hardware and field wiring.

Select the Proper Product for Your Intrinsically Safe Application

Before selecting the best protection method, examine the mix of analog and digital signals, whether a ground is available, amount of cabling required, and space in the control room. There are enough options available now to simplify the installation and reduce the system costs.

Many different products will make a sensor or instrument intrinsically safe. Many times selecting the correct product is troublesome for the first time user. For a complete explanation on how to select the proper barrier refer to the website. www:ISBARRIERS.com

Installation, Maintenance and Troubleshooting of Intrinsically Safe Circuits

Explosionproof seals are not required if a suitable mastic is used that prevents the transmission of gases. No special maintenance for intrinsically safe circuits is required.

  • Intrinsically safe circuits use normal wiring practices, but care must be taken to separate and identify these circuits.
  • A proper grounding system will have only one grounding point.
  • There are five rules of grounding to ensure the system is safe.
  • Explosionproof seals are not required.
  • Intrinsically safe seals must prevent the transmission of gases.
  • No special maintenance is required.
  • Troubleshooting the system includes: checking that the wiring is installed correctly, the circuit is powered, the barrier resistance is not too high and the fuse is not blown.

The intrinsically safe system must be properly installed and provisions must be made to maintain and troubleshoot it. These provisions are discussed in detail in Article 504 of the National Electrical Code (NEC) and the ANSI/ISA RP 12.6-1987 Recommended Practice Installation of Intrinsically Safe Systems For Hazardous (Classified) Locations.

Wiring

Intrinsically safe circuits may be wired in the same manner as comparable circuits installed for unclassified locations with two exceptions summarized as separation and identification. These wiring practices are simple and clear; however, they often are overlooked and are the source of potential problems. The intrinsically safe conductors must be separated from all other wiring by placing them in separate conduits or by a separation of a minimum of 2 inches of air space. Within an enclosure the conductors can be separated by a grounded metal or insulated partition (see figure 6).

Barrier Installation

Intrinsic Safety – IAEI Magazine (11)

Figure 7. Conductive dust or moisture could lessen the required distance of 2 inches between intrinsically safe and non-intrinsically safe conductors

The barriers normally are installed in a dust- and moisture-free IP 54 or NEMA 4 or 12 enclosure located in the non-classified area. Only the barrier outputs are intrinsically safe. Conductive dust or moisture could lessen the required distance of 2 inches between intrinsically safe and non-intrinsically safe conductors (see figure 7). The enclosure should be as close as possible to the hazardous area to minimize cable runs and increased capacitance of the circuit. If they are installed in a hazardous area, they must be in the proper enclosure suited for that area.

Grounding

First determine if the intrinsically safe barriers used in the system are grounded or isolated. The isolated barriers normally are larger, more expensive, and do not require a ground for safety. The grounded safety barriers are smaller and less expensive, but require a ground to divert the excess energy. The main rules of grounding intrinsically safe systems are:

  • The ground path must have less then 1 ohm of resistance from the furthest barrier to the main grounding electrode.
  • The grounding conductor must be a minimum 12 AWG.
  • All ground path connections must be secure, permanent, visible, and accessible for routine inspection.
  • A separate isolated ground conductor normally is required since the normal protective ground conductor (green or yellow/green wire) may not be at the same ground potential because of the voltage drop from fault currents in other equipment.
  • For installations designed to Canadian standards, the Canadian Electrical Code (Appendix F) recommends redundant grounding conductors.

Intrinsic Safety – IAEI Magazine (12)

Figure 8. Figure 8 shows an improperly grounded system

A poor grounding system can influence the function of the system by creating noise on the circuit or modifying the signals. Figure 8 shows an improperly grounded system. The numerous grounding points create ground loops which can modify the signals and induce stray voltages into the intrinsically safe circuits. The correct method of grounding is shown in figure 4 where all the grounds are tied together at one single point in the system. [See figure 9]

Sealing

The requirements for sealing intrinsically safe circuits have been discussed by a panel of experts and published in “”Seals for Intrinsically Safe Circuits,”” EC&M, September 1992, pp. 48-49. The panel’s conclusion is that boundary seals are required to prevent the transmission of gases and vapors from the hazardous area to the non-hazardous area, not to prevent passage of flames from explosions. Explosionproof seals are not required as long as there is some other mechanical means of preventing the passage of gases such as positive pressure in the control room and/or application of an approved mastic at cable terminations and between the cable and raceway. Many experts generally agree that a commercially available silicon caulk is a suitable mastic which would minimize the passage of gases. This must, however, be acceptable to the authority having jurisdiction.

Intrinsic Safety – IAEI Magazine (13)

Figure 9. Correct grounded system where all the grounds are tied together at one single point in the system

When barriers are installed in explosionproof enclosures, which are located in the hazardous area, explosionproof seals are required on the enclosure (see figure 10). Since other conduits containing non-intrinsically safe conductors between the hazardous and non-hazardous areas require explosionproof seals, it is good practice to maintain consistency and install explosionproof seals on the conduits containing intrinsically safe conductors also. The exception to this would be where multi-conductor shielded cable is used. This cable may be difficult to seal in some explosionproof fittings. However, it will be necessary to seal both the cable terminations and between the cable and raceway to minimize the passage of gases, vapors, or dust.

9.5.5 Maintenance

Intrinsic Safety – IAEI Magazine (14)

Figure 10. When barriers are installed in explosionproof enclosures, which are located in the hazardous area, explosionproof seals are required on the enclosure

No special maintenance of intrinsically safe systems is required. Once a year the barriers should be checked to ensure that the connections are tight, the ground wiring has less then one ohm of resistance, and the barriers are free from moisture and dirt. Check the panel and conduits for separation and identification of the intrinsically safe wiring. Never test the barrier with an ohmmeter or other test instrument while it is connected in the circuit (see figure 11). This bypasses the barrier and could induce voltages into the intrinsically safe wiring.

9.5.6 Troubleshooting

Intrinsic Safety – IAEI Magazine (15)

Figure 11. Never test the barrier with an ohmmeter or other test instrument while it is connected in the circuit

If the intrinsic safety circuit does not operate properly once it is completed and energized, follow these troubleshooting guidelines:

  • Make sure the connections are tight.
  • Check the wiring to the appropriate terminals against the control wiring diagram. A control wiring diagram is defined by the NEC as “a drawing or other document provided by the manufacturer of the intrinsically safe or associated apparatus that details the allowed interconnections between the intrinsically safe and associated apparatus.” These diagrams are easier to obtain than in the past. Make sure that one of the manufacturers provides not only diagrams which show the interconnections between the field device and barriers, but also wiring diagrams which demonstrate that the circuit functions properly and is safe by comparing the safety parameters of the field device and the barriers.
  • Make sure the circuit is powered.
  • Check to see if the resistance in the barrier is too high for the circuit. As stated in the previous articles in this series, circuits are analyzed for the proper loop resistance (barrier and cable) and supply voltages. If the circuit does not operate properly, check the circuit against the design in the control wiring diagram.
  • Check for a blown barrier fuse, by disconnecting the barrier from the circuit and measuring the end-to-end resistance of the barrier. If the ohmmeter registers an infinite resistance, the fuse in the barrier is blown. The fuse has opened because of a fault in the circuit, so reevaluate the entire circuit before reinstalling a new barrier.

9.5.7 Barrier Replacement
If the barrier’s fuse has opened, it usually is the result of excessive voltage being applied to the barrier. This causes the diode to conduct, which results in high current in the fuse. After determining the cause of the excess voltage, the barrier must be replaced. The procedure is to disconnect the wiring from the safety barriers in the proper order of non-hazardous terminal first, hazardous terminals next, and the ground last. Cover the bare wire ends with tape, replace the barrier, and then reverse the procedure to mount the new barrier. Always install the ground first and disconnect the ground last.

FAQs

How do you know if a device is intrinsically safe? ›

In general, equipment meeting the T4 designation is considered intrinsically safe because temperatures will not exceed 135°C (275°F) (equipment dissipating less than 1.3 W generally stays below this temperature).

What qualifies as intrinsically safe? ›

A device which is termed "intrinsically safe" has been designed to be incapable of producing heat or spark sufficient to ignite an explosive atmosphere, even if the device has experienced deterioration or has been damaged.

Is intrinsically safe the same as ATEX? ›

ATEX is the European certification given to equipment tested and approved to be intrinsically-safe. There are two European Directives in place for the control of explosive atmospheres: Directive 1999/92/EC (also known as 'ATEX 153' or the 'ATEX Workplace Directive')

What is the difference between non incendive and intrinsically safe? ›

A non-incendive device prevents ignition under normal conditions. An intrinsically safe device prevents ignition in doublefault conditions.

Are LED lights intrinsically safe? ›

Intrinsically safe lighting is low-powered lighting, often incorporating batteries and rechargeable batteries. This lighting often makes use of low-voltage bulbs, like light emitting diodes (LEDs). Halogen flashlights and high-intensity discharge lights (HID) are often classified this way.

What is the difference between Ex ia and Ex ib? ›

certification namely; Ex ia and Ex ib. Both certifications are termed I.S. but they have differing end-use applications. Ex ia may be used in a Zone 0, Zone 1 or Zone 2 explosive area where Ex ib may only be used in Zone 1 or Zone 2 explosive area.

Are batteries intrinsically safe? ›

The International Electrotechnical Commission (IEC) standard 60079-11 dictates that to be considered “intrinsically safe” such components, including batteries, should not produce sparks and should not release electrical or thermal energy that could cause ignition of flammable or combustible atmospheres, even under ...

Is explosion proof intrinsically safe? ›

Intrinsically safe means that the piece of equipment itself can't cause an explosion. Meanwhile, explosion-proof means that if an explosion did happen, the device would be protected by an explosion-proof enclosure that helps contain explosions and prevent them from spreading.

Is a multimeter intrinsically safe? ›

The Fluke 28 II Ex digital multimeter is an intrinsically safe digital multimeter designed for troubleshooting in dangerous or explosive environments.

Do intrinsically safe cables have to be blue? ›

Intrinsically safe cables are usually coloured blue so as to identify the potential risk of the electric circuit and the need for special consideration. The cables are often protected by tough sheathing materials such as polyurethane to prevent any mechanical damage which could compromise electrical safety.

Are RFID tags intrinsically safe? ›

Passive RFID tags are by definition “intrinsically safe”, according to IEC 60079-14 Ed. 5.0, but can also be optionally explicitly certified for use in one or more of the ATEX zones.

Who certifies intrinsically safe? ›

Certifying agencies include international, national, and industry bodies. Most try to ensure their certifications are compatible with one another. Some major certifying agencies for intrinsic safety include: Underwriters Laboratories.

What is the maximum voltage for intrinsically safe? ›

Intrinsic safety is the method of protection for control and instrumentation circuits where the nominal voltage is 24 VDC or less and the current is normally less than 100 mA.

What zone is intrinsically safe? ›

While there are a number of different ATEX ratings the most common are ATEX Zone 2 (lowest risk), ATEX Zone 1 and ATEX Zone 0 (Highest risk). Most of the products at Intrinsically Safe Store are Zone 2 & 1 as this is the most common in industrial use.

What are the 3 classes of hazardous locations? ›

The National Electric Code classifies hazardous locations in three ways: TYPE, CONDITION, and NATURE. There are three types of hazardous conditions: Class I - gas and vapor, Class II dust, and Class III - fibers and flyings.

Is USB intrinsically safe? ›

Since the USB barrier provides an intrinsically safe circuit, the connected USB keyboard does not need to be purged and pressurized if it is certified for use in Zone 1/21.

Are Apple products intrinsically safe? ›

Whilst the iPhone & iPad are not intrinsically safe by themselves they can be made intrinsically safe through the addition of a 3rd party case that is intrinsically safe.

Is 12v intrinsically safe? ›

Furthermore, the LV12 has ATEX and IECEx intrinsically-safe approval for use in explosive volatile environments – ideal for safe use in the gas and petrochemical sectors.

Does ATEX mean explosion proof? ›

The word "ATEX" is derived from the term "ATmospheres EXplosibles". The term ATEX is the widely used synonym for the explosion protection directives in the European Union. The directive currently includes the following two directives in the field of explosion protection: Product Directive 2014/34/EU.

Is flameproof same as explosion proof? ›

The terms explosion proof and flameproof have the same meaning in that they are constructed in such a way that an internal ignition of a flammable atmosphere will not be transmitted outside of the enclosure and thereby preventing the ignition of surrounding flammables.

What is the difference between intrinsically safe and flameproof equipment? ›

Hazardous Areas containing gas, vapors or mist are classified into zones. Intrinsic safety equipment is suitable for use in Zone 0, Zone 1 and Zone 2, while explosion proof protection is only suitable for use in Zone 1 and Zone 2, not in Zone 0.

Are digital cameras intrinsically safe? ›

Additionally, digital cameras in explosive areas will contain marks of certifications such as ATEX Zone 1, ATEX Zone 2, Class 1 Division 1, Class 1 Division 2, IECEx, and more. A camera is Intrinsically safe if it passes rigorous testing and certification standards.

What makes a flashlight intrinsically safe? ›

When authorities consider a flashlight as “intrinsically safe” (IS), this means that the flashlight is designed not to produce sparks to ignite the surrounding material. Also, Intrinsic safety protects against abnormally high temperatures of small components inside the flashlight.

Is fiber optic cable intrinsically safe? ›

Also, some specialized vendors have developed fiber optics (FO) cables/connectors for hazardous areas. But in general, FO cables can introduce an ignition source in a hazardous environment. They are not intrinsically safe.

Are GoPro cameras intrinsically safe? ›

GoPro cameras are NOT certified for IECEx or ATEX and there are currently no plans to do so. This also means that the camera is not 'intrinsically safe'.

What is the most explosion resistant material? ›

Polycarbonate can withstand blasts of over 900 psi and is about 200 times stronger than steel by weight, and is also more flexible than steel. This feature allows polycarbonate to flex and return to its original shape, dissipating impact energy.

Are thermocouples intrinsically safe? ›

When thermocouples and RTD's (resistance temperature devices) are installed in hazardous areas, barriers are required to make their circuits intrinsically safe. These intrinsic safety barriers prevent excess energy from possible faults on the safe side from reaching the hazardous area.

How do you make a device intrinsically safe? ›

What Should Electronics Manufacturers Do to Meet Intrinsically Safe Design Guidelines?
  1. Limit Power. Try splitting the power in a device into multiple circuits. ...
  2. Consider Voltage-Enhancing Circuits. ...
  3. Choose Batteries Carefully. ...
  4. Avoid Sealant Defects. ...
  5. Utilize Protective Components.
16 Jul 2020

How do you make a circuit intrinsically safe? ›

Ten Ways to Design for Intrinsic Safety
  1. Batteries Should be Selected Carefully. ...
  2. Be Mindful of Multiple Power Sources. ...
  3. Be Skeptical of Published Electrical Ratings for Semiconductors. ...
  4. Calculate the Thermal Rise Characteristics of Power-Dissipating Components. ...
  5. Be Aware of Voltage-Enhancing Circuits.
4 Apr 2016

Are Fluke meters intrinsically safe? ›

Fluke Corporation, the global leader in portable electronic test and measurement technology, introduces the 28II-EX and 87V-EX rugged, intrinsically safe digital multimeters that allow measurements both inside and outside of hazardous zones without compromising measurement performance.

Is Ethernet intrinsically safe? ›

The Ethernet Isolator is an intrinsically safe isolated barrier. It enables cost effective and simple installation in hazardous areas up to Zone 0. It supports high-speed Ethernet and can be mounted in Zone 2. At each end of the trunk, an Ethernet Isolator is installed.

Are drones intrinsically safe? ›

While intrinsic safety describes a set of electrical design principles, it also considers deployment procedures too. UAV platforms are not fully intrinsically safe in their electrical design.

IS and NIS cable difference? ›

Difference between IS and Non-IS cables

The IS cable outer sheath insulation color is BLUE (most of cases) to identify in the plant which cables are IS cables while non IS cable outer sheath color is either Black or Grey.

Will any metal block RFID? ›

The RFID's Magnetic Shield

The most used metals for RFID blocking materials are copper, aluminum, and alloy nickel, among others. In particular, the one that is easiest to use is aluminum.

Can RFID pass through metal? ›

Radio frequency identification cannot pass through metal. In a passive RFID system, radio waves sent by a reader to power up a tag would bounce off metal and never reach the tag; thus, it would not be able to respond.

Can RFID pass through plastic? ›

RFID scanners use radio frequency energy rather than visible light to read the RFID tag, so they can read tags through a wide variety of opaque materials like plastic, cardboard, composites or laminates.

Is iPhone 13 intrinsically safe? ›

XCiPhone 13

Now you can use an intrinsically safe iPhone 13 in a Class 1 Div 2 area or ATEX Zone 2 area.

Is ATEX a legal requirement? ›

The ATEX Directive in UK law

EU Directives become law if they are adopted by individual countries. In the UK, ATEX became law through two Acts: ATEX 137 was implemented under The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) by The Health and Safety Executive.

What is ATEX stand for? ›

What Does ATEX Stand For? ATEX comes from the description of the hazardous materials in question, as written in French — “Appareils destinés à être utilisés en ATmosphères EXplosives.” The translation into English reads, “Devices intended for use in explosive atmospheres.”

What are the three sub groups of intrinsic safe apparatus? ›

There are three main types of NEC 70 intrinsically safe levels: Class I, Class II, and Class III. Class I: The Class I environment has to do with flammable gasses and vapors. These vapors could be gasoline, hydrogen, natural gas propane, ethanol, or methane.

What are the two common type of barriers used in intrinsic safe apparatus? ›

Intrinsically safe barriers are used to interface between electrical devices in a hazardous location, and electrical devices located in the safe area (associated apparatus). The two types of barriers are passive barriers and galvanically isolated barriers.

What voltage is unsafe touch? ›

In industry, 30 volts is generally considered to be a conservative threshold value for dangerous voltage. The cautious person should regard any voltage above 30 volts as threatening, not relying on normal body resistance for protection against shock.

How do you know if equipment is intrinsically safe? ›

In general, equipment meeting the T4 designation is considered intrinsically safe because temperatures will not exceed 135°C (275°F) (equipment dissipating less than 1.3 W generally stays below this temperature).

Which is better T1 or T6? ›

T Rating Equipment

A T Class rating of T1 means the maximum surface temperature generated by the instrument at 40° C is 450° C. A rating of T6 means the maximum surface temperature generated by the equipment is 85° C.

What is difference between Zone 1 and Zone 2? ›

Zone 1: An area in which an explosive gas atmosphere is likely to occur in normal operation; Zone 2: An area in which an explosive gas atmosphere is not likely to occur in normal operation and, if it occurs, will only exist for a short time.

What indicates intrinsically safe electrical equipment? ›

So, What Does 'Intrinsically Safe Equipment' Mean? Basically, intrinsically safe electronics allow for safe operation in hazardous areas by limiting the electrical or thermal energy available for ignition. Common industrial equipment like motor brushes and switches are at risk of: Internal sparks.

What is an intrinsically safe electrical device? ›

Intrinsically safe equipment is defined as "equipment and wiring which is incapable of releasing sufficient electrical or thermal energy under normal or abnormal conditions to cause ignition of a specific hazardous atmospheric mixture in its most easily ignited concentration." This is achieved by limiting the amount of ...

What makes electronics intrinsically safe? ›

What Is Intrinsically Safe Design? Intrinsically safe electronics contain explosion-proofing designs in that the circuitry or equipment itself is incapable of producing sufficient electrical or thermal energy to ignite an explosion, whether operating in normal or abnormal conditions.

What is a non intrinsically safe device? ›

What Non-Intrinsically Safe Is. Non-Intrinsically Safe equipment comprises devices and methods that are not optimized to function at a lower energy output than average. And, non-Intrinsically Safe equipment may incorporate techniques such as isolation, Explosion-Proof, or containment.

Does intrinsically safe cable have to be blue? ›

Intrinsically Safe Cables: Overview

Electrical cables for intrinsically safe circuits (separate power circuit of hazard type-i) have to be specially marked with a blue outer jacket (RAL 5015) according to DIN VDE.

Is IP55 intrinsically safe? ›

What features to look for an effective Intrinsically Safe Radio. Most Intrinsically Safe radios contain the features found below: IP55 Water and Dust Resistant. MIL-STD-810-C, -D and -E.

Why are phones not intrinsically safe? ›

Mobile phones are not intrinsically safe, meaning that they have the potential to produce a spark of such intensity that it could ignite a vapour air mix.

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Name: Mrs. Angelic Larkin

Birthday: 1992-06-28

Address: Apt. 413 8275 Mueller Overpass, South Magnolia, IA 99527-6023

Phone: +6824704719725

Job: District Real-Estate Facilitator

Hobby: Letterboxing, Vacation, Poi, Homebrewing, Mountain biking, Slacklining, Cabaret

Introduction: My name is Mrs. Angelic Larkin, I am a cute, charming, funny, determined, inexpensive, joyous, cheerful person who loves writing and wants to share my knowledge and understanding with you.