IS barriers in ESD panel
- Thread starter RasPLC01
- Start date
James Mcquade
Member
if i understand your question correctly,
IS(isolation barriers) are devices used to isolate the sensor/device from the electrical power side of the system.
you are puttting up a wall between the two worlds and only allow a small door to go between them which restricts the electrical power and return signal.
i'm not sure of your exact situation, but you are trying to prevent the raw electrical power from getting into the production side of things because of some electrical hazard or the potential of fire / explosion.
regards,
james
IS(isolation barriers) are devices used to isolate the sensor/device from the electrical power side of the system.
you are puttting up a wall between the two worlds and only allow a small door to go between them which restricts the electrical power and return signal.
i'm not sure of your exact situation, but you are trying to prevent the raw electrical power from getting into the production side of things because of some electrical hazard or the potential of fire / explosion.
regards,
james
Ken Moore
Lifetime Supporting Member
In my world I.S. barrier means instrinsically safe barrier, and they limit current to field devices to ensure there is not enough energy to generate a spark in hazardous environments.
And in the UK, I(ntrinsically) S(afe) circuits would typically use blue sheathed cable, terminal blocks, etc, to clearly differentiate them from non-IS circuits (which would be suitably segregated from IS).
If your existing I/O is indeed Intrinsically Safe, then any new I/O in the same field area needs to be IS (unless the zone classification has changed). As has been said, Intrinsically Safe barriers are used to provide protection to allow electrical equipment to be used in Hazardous areas - modification to such a system should not be made without a good knowledge of the area, system and protection concepts,
regards
Dave
If your existing I/O is indeed Intrinsically Safe, then any new I/O in the same field area needs to be IS (unless the zone classification has changed). As has been said, Intrinsically Safe barriers are used to provide protection to allow electrical equipment to be used in Hazardous areas - modification to such a system should not be made without a good knowledge of the area, system and protection concepts,
regards
Dave
Last edited:
Ned_Flanders
Member
Yes, you need much more information and the area classification will determine what type of IS circuit devices you need.(How onerous the zone)
In this situation, I would do exactly what the designer said.
If the specifications or standards relating to the existing installation require it, then yes. It should be fairly easy to identify if the existing PLC/panel is in a 'Safe Area' or in a zoned, hazardous area. The type of enclosure is a good pointer. A hazardous area panel will be considerably larger (due to material thickness etc.) and all PB's, lamps etc. will also be rated accordingly.
If your PLC is located in a safe area, then you may be required to install IS barriers between hazardous areas and your control panel. Do you have any client specifications you need to comply with?
Rob
Thanks for All Replys
I have a ESD system in ICS triplex Trusted. panel will be installed inside control room. but instruments are in Diesel loading area. I am going to use knife edge terminals to field side connection. but i heard about IS Barriers and confused.
I have no other information from client
I have a ESD system in ICS triplex Trusted. panel will be installed inside control room. but instruments are in Diesel loading area. I am going to use knife edge terminals to field side connection. but i heard about IS Barriers and confused.
I have no other information from client
Intrensictly safe barriers are as stated in prior posts, I have seen them used exstensivley in vibration monitoring engine systems in class 1 div 1 areas.
The thread below doesn't directly answer your question, but you may get a better understanding of IS barriers in general (i have posted some typical electrial arrangements)
http://www.plctalk.net/qanda/showthread.php?t=69946
Regards,
Rob
http://www.plctalk.net/qanda/showthread.php?t=69946
Regards,
Rob
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