card reader in class I div.I
- Thread starter dylan
- Start date
- Status
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I did a Google search on ?card reader hazardous? and found several possible alternatives.
It is conceivable that you could use the unit you suggested with an intrinsically safe power supply; however, it would take the manufacturer to produce a ?control drawing? (see Section 504. 10(A) and the definition in Section 500.2).
It is conceivable that you could use the unit you suggested with an intrinsically safe power supply; however, it would take the manufacturer to produce a ?control drawing? (see Section 504. 10(A) and the definition in Section 500.2).
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Is there no way to move the card reader just outside the classified location?
- Location
- Illinois
- Occupation
- retired electrician
How can people be working in a Class I, Divison 1 location? In many cases the atmosphere created by flammable gasses is IDLH(Immediately Dangerous to Life and Health), requiring the use of supplied breathing air, at about 10% of LEL. If the gasses are only at 10% of LEL it should not be Class I, Divison 1.
Don
Don
don_resqcapt19 said:
Great point. There are many facilities that routinely use solvents (with IDLH less than 10% LEL) that are overclassified as Div. 1. Many of them have "always been Div. 1, no reason to change it" in the words of some old timers.
We have re-assessed the EAC on many facilities using Health and Safety basis. Fugitive emissions data, sampling, incident reports, have provided a basis for Div. 2 classification where Div. 1 was previously assumed. This has worked well in Pharma and Chemical industries. There are many small rooms in some of these facilities where a leak can easily overcome the ventilation system and Div. 1 is still advisable. Vessel charging may require a 5' Div. 1 radius and is performed with PPE. Also, remember "normal or frequent".
In oil and gas, especially in cold climates, buildings may be inadequately ventilated or manned by operators only during scheduled rounds or "call-outs" and Div. 1 can be required, especially if adequate gas detection is not provided.
Bob
- Location
- Illinois
- Occupation
- retired electrician
Bob,
In these areas that remain division 1, is respiratory protection or "sniffing" required for personnel entry?
Don
In these areas that remain division 1, is respiratory protection or "sniffing" required for personnel entry?
Don
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Don,
One of the more subtle differences between the US domestic ?Division? classification system and the IEC ?Zone? system is that the US Divisions are defined in terms of ?possibility? and IEC Zones are defined in terms of ?probability.? I pointed this out to CMP14 several years ago and they redefined US Zones to be consistent with the ?Division? concepts. That wasn?t my intention, but it is what they did.
I can describe a Division 1 location that may never actually be ?hazardous? through its active lifetime. One prime example is the envelope around a vapor relief port. Typically there is a 3 to 5? Division 1 envelope. If the valve never engages (a fairly common case), the area is really not very likely to be flammable. But, since it is possible, it?s Division 1.
As Bob pointed out, many cold locations with enclosed operating areas and poor ventilation are also classified Division 1 ? not because they actually do have flammable mixtures present, but because they could under ?normal? conditions. Remember. ?normal? is not necessarily ?common.?
BTW that is another difference. ?Normal? is undefined in US domestic use but it is a defined term in the IEC system classification.
One of the more subtle differences between the US domestic ?Division? classification system and the IEC ?Zone? system is that the US Divisions are defined in terms of ?possibility? and IEC Zones are defined in terms of ?probability.? I pointed this out to CMP14 several years ago and they redefined US Zones to be consistent with the ?Division? concepts. That wasn?t my intention, but it is what they did.
I can describe a Division 1 location that may never actually be ?hazardous? through its active lifetime. One prime example is the envelope around a vapor relief port. Typically there is a 3 to 5? Division 1 envelope. If the valve never engages (a fairly common case), the area is really not very likely to be flammable. But, since it is possible, it?s Division 1.
As Bob pointed out, many cold locations with enclosed operating areas and poor ventilation are also classified Division 1 ? not because they actually do have flammable mixtures present, but because they could under ?normal? conditions. Remember. ?normal? is not necessarily ?common.?
BTW that is another difference. ?Normal? is undefined in US domestic use but it is a defined term in the IEC system classification.
don_resqcapt19 said:
Yes for some. No EH&S dept will condone entry without. But electrical could be in place and energized in these areas while personnel may only be in these areas occasionally. Example, energized heat trace or lighting near a pipeline "pig" launcher.
Remember, EAC is performed for the installation of electrical equipment in hazardous areas. EAC does not cover the catalytic converter on your car, but other safety rules would prevent you from parking your car, with hot mechanical surfaces car next to a hexane loading station. EAC is not the basis for personnel exposure safety (although personnel exposure safety can be part of the basis for EAC).
NEC does not quantify normal or frequent. Eurpoean standards do, I believe. See Magison's book for discussions on the subject.
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
If you are willing to consider alternative card readers, then perhaps a non-contact proximity card system might work well, as the guts of the reader can be on the other side of the wall, and thus outside the Class 1 Div 1 area...?
- Location
- Illinois
- Occupation
- retired electrician
Even with the fact that the code say that a Divison 1 locations are "those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitible mixtures." Once you make the Divison 1 classification, the EHS department should be requiring a test for the atmosphere before any one enters the area. I understand that the basis of the classification is [not] personnel safety, but once some one has actually put on paper the fact that the atmosphere in the area is or maybe above LEL under normal operating conditions, you really have no choice but to test or protect for any entry into the area. To do otherwise is a serious safety and liability risk.
Don
Edited to add missing word [not]
Don
Edited to add missing word [not]
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- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Don,
You are now touching on another root difference between the US and the IEC classification systems.
If you read the scope/purpose statements of the primary US area classification documents (API RP 500/505 and NFPA 497) you will find they are [intended] for electrical area classification exclusively. The EU implementation documents for IEC (there are several such as the British Institute of Petroleum’s IP 15) recognize using area classification for other purposes. This includes effects on mechanical equipment placement with no regard to electrical equipment at all as well as confined space access and other issues.
Zone 0 would definitely require the added measures you mentioned, Zone 1 may not. The root methods of analysis are different (I wrote an entire IEEE paper on this and won't even attempt to repeat it here) and would not necessarily lead to Zone 1 needing additional precautions.
CMP14s attempt to “force-fit” the Zone system into the Division philosophy was one of my primary objections.
Edit added "intented" where [bracketed]
You are now touching on another root difference between the US and the IEC classification systems.
If you read the scope/purpose statements of the primary US area classification documents (API RP 500/505 and NFPA 497) you will find they are [intended] for electrical area classification exclusively. The EU implementation documents for IEC (there are several such as the British Institute of Petroleum’s IP 15) recognize using area classification for other purposes. This includes effects on mechanical equipment placement with no regard to electrical equipment at all as well as confined space access and other issues.
Zone 0 would definitely require the added measures you mentioned, Zone 1 may not. The root methods of analysis are different (I wrote an entire IEEE paper on this and won't even attempt to repeat it here) and would not necessarily lead to Zone 1 needing additional precautions.
CMP14s attempt to “force-fit” the Zone system into the Division philosophy was one of my primary objections.
Edit added "intented" where [bracketed]
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- Location
- Illinois
- Occupation
- retired electrician
Bob,
When it comes down to the lawyers getting involved after an incident, I don't think it will matter, even one little bit, as to the real purpose of the classification. All that will matter is that some qualified person has made the determination that the atmosphere may or will be above LEL under normal operating conditions. Once that determination is made, there is no way that you can permit people to enter the area without protection.
Don
When it comes down to the lawyers getting involved after an incident, I don't think it will matter, even one little bit, as to the real purpose of the classification. All that will matter is that some qualified person has made the determination that the atmosphere may or will be above LEL under normal operating conditions. Once that determination is made, there is no way that you can permit people to enter the area without protection.
Don
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Well - that's what lawyers are for.
Personally, I have no problem with using electrical area classification to trigger an EHS review - but you may be surprised at the ultimate result of litigation based on it. Remember both API RP 500/505 and NFPA 497 are only recommended practices. That's still a pretty strong basis but I have no personal knowledge of any precedents that electrical area classification has ever been a successful basis for personal injury or worker damages not directly related to electrical issues.
Basic US domestic classification practices have been around a long time. I was an API 500/505 author for the last three editions and we were never informed by the legal group of any such current or pending litigation either - and we were informed about a lot of current and pending legal actions.
Personally, I have no problem with using electrical area classification to trigger an EHS review - but you may be surprised at the ultimate result of litigation based on it. Remember both API RP 500/505 and NFPA 497 are only recommended practices. That's still a pretty strong basis but I have no personal knowledge of any precedents that electrical area classification has ever been a successful basis for personal injury or worker damages not directly related to electrical issues.
Basic US domestic classification practices have been around a long time. I was an API 500/505 author for the last three editions and we were never informed by the legal group of any such current or pending litigation either - and we were informed about a lot of current and pending legal actions.
- Location
- Illinois
- Occupation
- retired electrician
Bob,
Don
Maybe I just opened a big can of worms for everyone involved.:grin:
Don
- Status