brock.aslan
Member
- Location
- Ohio
- Occupation
- Engineer
[TLDR] For Intrinsically Safe systems, when putting together a DSD, what Entity Parameters are you supposed to use? It seems like each Table of parameters I've seen is missing some important information that would tell me why I need to use one over the other.
I have been struggling to design an intrinsically safe circuit, so I'm hoping that I can get some clarification on a few things in Pepperl+Fuchs literature:
I plan on using NCN3-F25-N4-V1 inductive sensors for a Class I, Zone 1/2 (NEC – USA) application. There will be ten (10) of these sensors mounted to the individual pneumatic actuators for our solution. My intention was to run these back to a 4-channel Switch Amplifier (KFD2-SRA-Ex4). From my understanding, I need to install these in accordance with the Control Drawings, which is fine.
My intention would be to run two (2) different sensors, both the open and closed signals, to one (1) switch amplifier, which would make up the four (4) channels of the amplifier. When I look at the Control Drawing (116-0145E) of the Switch Amplifier, it allows me to connect to either a Simple Apparatus, which a proximity sensor is NOT, or an approved device with appropriate Entity Concept parameters Voc < Vi and Isc < Ii and Po < Pi (??) and Lo > Lcable + Li and Co > Ccable + Ci. Not sure why Po is missing from the equation…
For the KFD2-SRA-Ex4: Voc = 10.6V, Isc = 19.5mA, Po = ??, Co (IIC) = 1.273uF, Lo (IIC) = 84.88mH.
When I look at the Control Drawing (116-0456) for the proximity sensor, Table 1 has three sets of values, without any reference to what Type 1, 2 or 3 is referring to, so I’m unsure if I can wire these four (4) sensor circuits to the amplifier based on that Table alone. Is Type 1, 2 and 3 ATEX specific? I don’t see any mention of it in NFPA or UL 698A.
I guess beyond the question that I mentioned above, is Po not a factor in determining suitability for this Switching Amplifier since it’s not listed on the Control Drawing? I would just need to make sure Voc, Isc, Lo and Co are appropriate? And if that’s the case, is it safe to conclude that I am able to use these sensors in tandem with the amplifier, as Voc = 10.6V < Vi =15V and Isc = 19.5mA < Ii = 25mA and Co and Lo are going to be pretty negligible, as the cable run will be less than 10 meters.
I have been struggling to design an intrinsically safe circuit, so I'm hoping that I can get some clarification on a few things in Pepperl+Fuchs literature:
I plan on using NCN3-F25-N4-V1 inductive sensors for a Class I, Zone 1/2 (NEC – USA) application. There will be ten (10) of these sensors mounted to the individual pneumatic actuators for our solution. My intention was to run these back to a 4-channel Switch Amplifier (KFD2-SRA-Ex4). From my understanding, I need to install these in accordance with the Control Drawings, which is fine.
My intention would be to run two (2) different sensors, both the open and closed signals, to one (1) switch amplifier, which would make up the four (4) channels of the amplifier. When I look at the Control Drawing (116-0145E) of the Switch Amplifier, it allows me to connect to either a Simple Apparatus, which a proximity sensor is NOT, or an approved device with appropriate Entity Concept parameters Voc < Vi and Isc < Ii and Po < Pi (??) and Lo > Lcable + Li and Co > Ccable + Ci. Not sure why Po is missing from the equation…
For the KFD2-SRA-Ex4: Voc = 10.6V, Isc = 19.5mA, Po = ??, Co (IIC) = 1.273uF, Lo (IIC) = 84.88mH.
When I look at the Control Drawing (116-0456) for the proximity sensor, Table 1 has three sets of values, without any reference to what Type 1, 2 or 3 is referring to, so I’m unsure if I can wire these four (4) sensor circuits to the amplifier based on that Table alone. Is Type 1, 2 and 3 ATEX specific? I don’t see any mention of it in NFPA or UL 698A.
I guess beyond the question that I mentioned above, is Po not a factor in determining suitability for this Switching Amplifier since it’s not listed on the Control Drawing? I would just need to make sure Voc, Isc, Lo and Co are appropriate? And if that’s the case, is it safe to conclude that I am able to use these sensors in tandem with the amplifier, as Voc = 10.6V < Vi =15V and Isc = 19.5mA < Ii = 25mA and Co and Lo are going to be pretty negligible, as the cable run will be less than 10 meters.