What is the difference between Exia, Exib and Exic
We have an understanding that Exi means Intrinsic Safe protection.
However it is further divided into 3 Types
1) Exia
2) Exib
3) Exic
The key difference between these 3 types is its “fault tolerant capacity”.
The following diagram would help us to understand this concept in a simpler manner
However it is further divided into 3 Types
1) Exia
2) Exib
3) Exic
The key difference between these 3 types is its “fault tolerant capacity”.
The following diagram would help us to understand this concept in a simpler manner
1.Exia
Courtesy:Pepperl-fuchs
It has 3 Zener diodes and these are in parallel.
Thus 2 are redundant (i.e if two of them are faulty still the protection is enabled)
Thus it is said that in “Exia protection No ignition must be caused in normal operation by one fault or combination of any 2 faults”
Thus 2 are redundant (i.e if two of them are faulty still the protection is enabled)
Thus it is said that in “Exia protection No ignition must be caused in normal operation by one fault or combination of any 2 faults”
2.Exib
Courtesy:Pepperl-fuchs
It has 2 Zener diodes and these are in parallel.
Thus there is one redundant protection available for this protection concept.
Thus it is said that in “Exib protection No ignition must be caused in normal operation by one fault.
Thus there is one redundant protection available for this protection concept.
Thus it is said that in “Exib protection No ignition must be caused in normal operation by one fault.
3. Exic
Courtesy:Pepperl-fuchs
It has 1 Zener diode, Thus there is no redundant protection available in this protection concept
Thus it is said that in “Exic protection No ignition must be caused in normal operation”.
Thus it is said that in “Exic protection No ignition must be caused in normal operation”.
Where to use Exia, Exib & Exic protection method
Exia is suitable for Zone 0 Area (Thus it is also surely suitable for Zone 1, Zone 2 Area)
Exib is suitable for Zone 1 Area (Thus it is also surely suitable for Zone 2 Area),However it is not recommended be used for Zone 0 Area.
Exic is suitable for Zone 2 Area, However it is not recommended to be used for Zone 0 and Zone 1 Area.
Exib is suitable for Zone 1 Area (Thus it is also surely suitable for Zone 2 Area),However it is not recommended be used for Zone 0 Area.
Exic is suitable for Zone 2 Area, However it is not recommended to be used for Zone 0 and Zone 1 Area.
Conclusion
Exia is the most safest option out of these types of protect and Exic provides the least level of protection as compare to Exia and Exib .
However it depends on Area/Zone where it is used.As the requirements get stringent the more better protection method is then sought for.
However it depends on Area/Zone where it is used.As the requirements get stringent the more better protection method is then sought for.
