What is an intrinsic safety barrier?

Intrinsic Safety Barriers are devices which limit the power (energy) that can be delivered from a safe area into a hazardous area. Explosions are therefore prevented, not just contained, in explosion-proof conduit and heavy cast housings.

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

barriers – zener barriers and galvanic isolators.

How do you make an intrinsically safe circuit?

In normal operation, and in the event of a fault, the Intrinsically Safe Barrier protects the field circuit by preventing excess energy from reaching the hazardous area. There are three main components in the barrier that limit the voltage and current: a resistor, at least two Zener Diodes, and a fuse.

How do you select an intrinsically safe barrier?

Specifications. Selecting intrinsic safety barriers requires an analysis of specifications and approvals. Performance specifications include operating temperature and maximum number of channels (I/O). Maximum open circuit voltage (VOC) and maximum short circuit current (ISC) are also important considerations.

Where is an intrinsic safety barrier panel installed?

mounted in the hazardous area must first be approved for use in an intrinsically safe system. The barriers designed to protect the system must be mounted outside of the hazardous area (as shown above) in an area designated as Non-hazardous or safe in which the hazard is not and will not be present.

Is ATEX intrinsically safe?

The bottom line is that it is not possible to claim a product certified as intrinsically safe in Europe to EN60079-XX (ATEX) can be deemed as intrinsically safe certified in the United States or Canada and vice versa. For each country, the device should be tested in accordance with the local requirements.

What are the two electrical components used in barriers to create intrinsically safe circuits?

The intrinsically safe barrier limits the current with a resistor and the voltage with a zener diode.

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.

What is difference between explosion proof and intrinsically safe?

Explosion-proof equipment contains an explosion within itself. Creating heavy, thick equipment which can withstand an explosion allows for higher wattage. Whether equipment is intrinsically safe or explosion-proof, it’s designed to prevent a malfunction in electrical process equipment.

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 are intrinsic safety barriers?

Intrinsic safety barriers are devices that limit the current, voltage, and total energy delivered to a sensor in a hazardous area or flammable environment in order to prevent an explosion. There are several types of intrinsic safety (IS) devices.

What is an intrinsically safe loop?

In Intrinsically safe loops, a safety barrier is present between the “safe area” (non hazardous area) and the “hazardous area” (which may have explosive gases/vapors/dusts present), so that any fault that generates a high energy level, would not get carried over to the hazardous area because of the barrier.

What is the purpose of a safety barrier in a dam?

Just as a dam prevents all the water from going from one side to the other (rather it regulates the flow via sluice gates), so also does a safety barrier prevent all the energy from the control room side of the measurement circuit from going over to the hazardous area in the plant, it gets regulated.