Semantics of "Area Classification" and who should determined Areas

[fifty60]

I have looked for training focusing on NFPA 497, RP 500, or focusing on NFPA 70 Article 500, but have not found anything.

 

[rbalex]

It may be of some interest that the members of the Technical Committees that edit/author the various Standards that I mentioned earlier in Post #16; i.e., CMP 14 (NEC Arts 500 to 516), NFPA Technical Committee on Electrical Equipment in Chemical Atmospheres (NFPA 497) and API Subcommittee on Electrical Equipment (API RP 500) virtually all have "electrical" backgrounds. The API SOEE exclusively in fact.

I've said many times before Hazardous (Classified) Locations is NOT rocket science. It isn't trivial either; it DOES take some thought but any relatively competent individual can learn it.

NFPA occasionally offers training for Hazardous Locations - every instructor I've known is "electrical".

 

[drktmplr12]

I work in wastewater and water plant design. Most (9/10) times we (Electrical/I&C) are tasked with identifying classification types and areas, showing them on our plans. It impacts electrical/instrumentation installation costs more so then any other, with exception to perhaps HVAC/mechanical having to add ventilation systems. I think for this reason we often lead the discussion on the subject.

We have made a push to make it a design team discussion with mixed results.

 

[IntrinsicSafety]

They can be called "Hazardous Area Classification Drawings", "Electrical Area Classification Drawings", or anything similar. I prefer "Area Classification" because new standards recognize that non-electrical equipment can cause ignitions.

Most guidance on risk analysis says that such activities are best done with a multidisciplinary team (electrical, mechanical, HVAC, process, as appropriate), led by someone with appropriate experience. This (obviously) applies to area classification, but is (equally obviously) not always practical.

Area classification is generally the owner's responsibility.


I agree EEs are the ones often saddled with the responsibility of the area classification; I also agree they're not necessarily the best qualified.

 

[rbalex]

They can be called "Hazardous Area Classification Drawings", "Electrical Area Classification Drawings", or anything similar. I prefer "Area Classification" because new standards recognize that non-electrical equipment can cause ignitions.

Most guidance on risk analysis says that such activities are best done with a multidisciplinary team (electrical, mechanical, HVAC, process, as appropriate), led by someone with appropriate experience. This (obviously) applies to area classification, but is (equally obviously) not always practical.

Area classification is generally the owner's responsibility.


I agree EEs are the ones often saddled with the responsibility of the area classification; I also agree they're not necessarily the best qualified.

I have been mulling over how to respond to this and several of your other recent posts. It took me a while to realize you are in Canada - let me be clear, that's just fine.

I must confess it has been nearly 20 years since I was actively engaged with the Canadian Electrical Code, Part I and the corresponding Hazloc issues. In my opinion, Canada had just adopted IEC Zones correctly; i.e., :whole hog". As I recall, "Divisions" were relegated to an "Annex". I don't know if that is still the case.

The consequence though, is attempting to apply Canadian practices is just about as bad as attempting to us IEC practices, "straight out of the gate". The 60079 series, unless it has been ANSI/UL/ISA "sanitized" is meaningless in the US.

There are many IEC practices I appreciate, but the US Zones and IEC Zones just aren't quite compatible.

 

[IntrinsicSafety]

Hey Bob,

At risk of hijacking this thread:

As always, you are correct. Canada switched to Zones and put Division in Annex J of the CEC some time ago. (Although we only just got Zone dusts sorted in the latest edition.)


Almost all IEC 60079s have been adopted by ANSI/UL and CSA by now. At least as far as equipment goes.

Certainly (but not obviously), the various adaptations have no force outside of their relevant jurisdictions. So yes, EN and IEC are technically meaningless here.

However, as they are all 97% harmonized, I think it's fair to say they are close enough to equivalent for the purposes of most conversations. So - in most cases - "IEC 60079" can legitimately be read as "ISA", "UL", or "CSA", as appropriate.


Not to ignore the existing non-harmonized Div standards: NFPA 496, ISA 12.12.01, UL 1203, etc. There can still be stark differences.

Fortunately, the NEC has had Art 505.1 and Art 505.9 for a while, making Div and Zone certified product substitute-able (within appropriate limits).


Area classification is more fuzzy, IMHO.

I've done more ACs than some, not as many as others, and was fortunate enough to get education.

I'm currently of the opinion that any method will do as long as it's justifiable. So I'm perfectly happy to steal the best available guidance from any source.

Since some of the European standards are ahead of NFPA in this respect, and thus may provide an appropriate way to reduce the size of classified areas, I don't hesitate to consider them. Others may disagree.

Certainly, in areas where the NEC has specific definitions, I'll use those. Usually arguing against the NEC is a bad call. But it's legitimate to modify if you have sound engineering judgement.


It will also be useful to know that I am primarily an equipment designer - PCBs, enclosures, and such - which makes me a standards guy, not a Code guy.

As such, I do tend to skew towards design, standards and NRTLs, rather than installation, NEC/CEC and AHJs. I was hoping that perspective would prove useful to those few areas I may be able to comment on.


In any case, if I seem to be confounding the "USA approach" with the "Canadian", "European" or "IEC" approach, it's intended only to be a convenient approximation. I would never try any kind of cross-jurisdictional approach, nor should anyone else.

I would love to have the luxury of only having to consider a specific jurisdiction, but it's not in the cards for me. I'll try to be more specific in the future.

Having said all that, I stand by my previous comments.

 

[rbalex]

The problem with Section 505.9 is that pesky "A" in Section 505.9(C)(2)(3).

I was basically an electrical plant design engineer so classification practices are a major concern. I spent about a third of my career in IEC environments

As I mentioned, there are several Canadian practices, like TECK 90, I like but it doesn't comply with the NEC. My suggestion to the API Subcommittee on Electrical Equipment eventually became Type MC-HL. I also like "Ex e" terminals for Division 2 and they were a standard in my "spec" days. FWIW I suggested to the main "Division 0" manufacturing advocate in the early to mid 90's what became Section 501.5. (I was even happy with using "straight" IEC "Ex")

One major, but subtle, difference is there are no "ordinary location" location products acceptable in the IEC Zone system - even Zone 2. (That's where the pesky "A" came from originally)

There are other significant differences, that I don't see being ironed out in my lifetime.

 

[IntrinsicSafety]

It is indeed a pity we can't all (yet) get along.

 

[nollij]

My kind of issue is why should the electrical engineer bear the responsibility and hold the liability of determining the hazardous area class of a facility. Is it not the process engineers who have the most familiarity with the process equipment and process conditions.

I feel like when I see area class drawings that were/are done by our EPC's all that was done was copy and paste the application of the API figures without any actual true understanding of the process and what the actual literature of API says in determineing the extent of the areas.

I have attempted to revise the vernacular at this facility to refer to it as a Hazardous Area Classification as opposed to an EAC specifically for the purpose of the increased role that the documents play in our facility's risk analysis. The documents are used much beyond their scope and this is a relatively common practice in the petrochemical industry. In an API audit, an auditor asked me if there were any classified locations that extended into roadways where there is unregulated vehicular traffic. I started my explanation with "that is outside the scope of API RP 500 as it is only for determining the classification of locations for the purpose of installation of electrical equipment. But with that in mind, I will entertain the intent of your question..."

A Process Engineer can go from start to finish in developing a Hazardous Area Classification document with no assistance from myself, an Electrical Engineer. Whereas, I would not be able to do 90% of the work without the assistance of the Process Engineer's input. I could just draw a big box along the plot limits and call everything Class I Division 2 Groups B,C,D and be done with it (except for sumps, inadequately ventilated locations, etc.).

When changes are made to the Process, they don't always tell the Electrical folks to update the Area Classification. This facility has a very poor track record of that. It is mostly due to a generalized lack of understanding for Area Classification development among Process Engineers and what changes could result in an update to the documents.

There are also some folks who know enough to be a problem but not enough to understand nuance. Mostly people who carry the "large ignition source = unclassified so we can install general purpose equipment" notion.

 

[petersonra]

I have attempted to revise the vernacular at this facility to refer to it as a Hazardous Area Classification as opposed to an EAC specifically for the purpose of the increased role that the documents play in our facility's risk analysis. The documents are used much beyond their scope and this is a relatively common practice in the petrochemical industry. In an API audit, an auditor asked me if there were any classified locations that extended into roadways where there is unregulated vehicular traffic. I started my explanation with "that is outside the scope of API RP 500 as it is only for determining the classification of locations for the purpose of installation of electrical equipment. But with that in mind, I will entertain the intent of your question..."

A Process Engineer can go from start to finish in developing a Hazardous Area Classification document with no assistance from myself, an Electrical Engineer. Whereas, I would not be able to do 90% of the work without the assistance of the Process Engineer's input. I could just draw a big box along the plot limits and call everything Class I Division 2 Groups B,C,D and be done with it (except for sumps, inadequately ventilated locations, etc.).

When changes are made to the Process, they don't always tell the Electrical folks to update the Area Classification. This facility has a very poor track record of that. It is mostly due to a generalized lack of understanding for Area Classification development among Process Engineers and what changes could result in an update to the documents.

There are also some folks who know enough to be a problem but not enough to understand nuance. Mostly people who carry the "large ignition source = unclassified so we can install general purpose equipment" notion.

I was in a refinery once where the whole plant except for a few buildings was division 2 except for the parts that were division 1. It had some interesting quirks though.

They had smoking areas set up that were delineated by yellow lines on the floor. The area inside the yellow rectangle was an unclassified smoking area but outside the yellow rectangle was division 2.

They also had a number of regular motor vehicles I saw driving around the plant, even though allegedly it was division 2. I asked about that because it seemed to me a car was a pretty likely source of ignition and was told they had gotten special permits from the provincial government to have motor vehicles without catalytic converters so they were safe to drive in the division 2 areas. I never really bought into this idea, but that was what they told me.

 

[rbalex]

People drive through Division 2 daily without issue. See Figure 514.3.

 

[petersonra]

People drive through Division 2 daily without issue. See Figure 514.3.

I know. But how is that "safe"?

 

[nollij]

I was in a refinery once where the whole plant except for a few buildings was division 2 except for the parts that were division 1. It had some interesting quirks though.

They had smoking areas set up that were delineated by yellow lines on the floor. The area inside the yellow rectangle was an unclassified smoking area but outside the yellow rectangle was division 2.

They also had a number of regular motor vehicles I saw driving around the plant, even though allegedly it was division 2. I asked about that because it seemed to me a car was a pretty likely source of ignition and was told they had gotten special permits from the provincial government to have motor vehicles without catalytic converters so they were safe to drive in the division 2 areas. I never really bought into this idea, but that was what they told me.

Our entire company and all of the refineries around here except one have gone to a "no smoking in this facility, or anywhere on our property." Smokers have to drive a couple miles down the road for their smoke breaks. One of the refineries I hear still has their "smoke shacks" which are basically as you described: locations outside the hazardous area classification where they don't need to have a 4-way monitor and a hot work permit to smoke. I would love to have seen if anyone ever filled out a hot work permit to light up a cig in the middle of a process unit though...

For the vehicles without catalytic converters... did anyone point out that there are plenty other sources of ignition on a vehicle? Granted, I was at another one of my company's facilities and we were literally driving down a road with large process pumps not more than 10 feet from the van I was riding in. It was a different level of risk acceptance but their facility was a lot more "cramped" in terms of layout.

 

[rbalex]

I know. But how is that "safe"?

Considering potential spillage, it could even be considered Division 1 - but historic experience has shown it's no big deal.

 

[nollij]

People drive through Division 2 daily without issue. See Figure 514.3.

I suppose there are some areas that are "more" Division 2 than others and the awareness/training of the persons within those areas mitigates potential hazards that you would not otherwise expose to the general public. Can tell you it is not a wise idea to drive a vehicle over an oily water sewer drain at a petrochemical facility.

 

[rbalex]

Our entire company and all of the refineries around here except one have gone to a "no smoking in this facility, or anywhere on our property." Smokers have to drive a couple miles down the road for their smoke breaks. One of the refineries I hear still has their "smoke shacks" which are basically as you described: locations outside the hazardous area classification where they don't need to have a 4-way monitor and a hot work permit to smoke. I would love to have seen if anyone ever filled out a hot work permit to light up a cig in the middle of a process unit though...

For the vehicles without catalytic converters... did anyone point out that there are plenty other sources of ignition on a vehicle? Granted, I was at another one of my company's facilities and we were literally driving down a road with large process pumps not more than 10 feet from the van I was riding in. It was a different level of risk acceptance but their facility was a lot more "cramped" in terms of layout.

Odds are I've done work for your operation.

BTW blanket classifying Groups B,C,D is generally wasteful. Group B takes some fairly special enclosures.

When I started in the business it was indeed common practice to just classify virtually every process unit boundary Class I, Division 2, Group C & D. The major value being avoiding a TON of boundary seals if the units were accurately classified. The downside was Group C had a relatively low effective "T-Code".

 

[nollij]

Eh. The classified locations are typically contained to the operating "blocks" at this facility so it isn't the entire place. Security, safety and operations also get a bit frazzled when people light off fireworks by the tanks near the beach even though it is not a classified area. The classified areas are used for work permitting (hot work permits) and automotive permits and then there are just general rules for the facility (no smoking, no leaving vehicles running unattended, etc.).

All of the operating unit blocks were classified as Groups C,D or just Group D. Turns out there is a lot more hydrogen in the process streams when they started looking into it shortly after I started here. Process Engineering Manager just went straight to "There isn't an effective way to manage this in operating units where we regularly reconfigure the process and make changes over the decades. Moving forward, install Group B equipment within the operating unit blocks because it costs a lot less than going back, auditing all the installations and then revising them all to meet Group B."

Obviously this increases the cost for explosion-proof enclosures for the additional tolerances, flange length, and bracing strength for the flame-path but all of the non-incendive type equipment is a marginal cost impact. Overall, on a project's budget, doing Group B over C,D is not a huge hit (~0.05% additional project cost on a recent project). But, that is a lot cheaper than spending over $1MM to audit and revise the equipment in an operating unit from Group D to Group B.

In the same line of thinking, the Process Engineering Manager also told me that all electrical equipment needs to be T-3 or lower.

 

[rbalex]

If you're happy - so am I. I certainly don't want argue with your Process Engineering Manager either. He's definitely old school; T-3 is basically the old limit on Group C.

 

[MrJLH]

I have attempted to revise the vernacular at this facility to refer to it as a Hazardous Area Classification as opposed to an EAC specifically for the purpose of the increased role that the documents play in our facility's risk analysis. The documents are used much beyond their scope and this is a relatively common practice in the petrochemical industry. In an API audit, an auditor asked me if there were any classified locations that extended into roadways where there is unregulated vehicular traffic. I started my explanation with "that is outside the scope of API RP 500 as it is only for determining the classification of locations for the purpose of installation of electrical equipment. But with that in mind, I will entertain the intent of your question..."

A Process Engineer can go from start to finish in developing a Hazardous Area Classification document with no assistance from myself, an Electrical Engineer. Whereas, I would not be able to do 90% of the work without the assistance of the Process Engineer's input. I could just draw a big box along the plot limits and call everything Class I Division 2 Groups B,C,D and be done with it (except for sumps, inadequately ventilated locations, etc.).

When changes are made to the Process, they don't always tell the Electrical folks to update the Area Classification. This facility has a very poor track record of that. It is mostly due to a generalized lack of understanding for Area Classification development among Process Engineers and what changes could result in an update to the documents.

There are also some folks who know enough to be a problem but not enough to understand nuance. Mostly people who carry the "large ignition source = unclassified so we can install general purpose equipment" notion.

Yep that was the point I'm curious about what everyone on the forum thought. Yeah I can draw out a plant and put a bubble around the equipment, but it is the process engineering who have the technical knowledge and expertise of what goes on with the units.

 

[rbalex]

Yep that was the point I'm curious about what everyone on the forum thought. Yeah I can draw out a plant and put a bubble around the equipment, but it is the process engineering who have the technical knowledge and expertise of what goes on with the units.

I have served on three national level "HazLoc" Technical Committees. Almost without exception, the membership was all "electrical", the lone exception was the API Subcommittee on Electrical Equipment (API RP 500 and 505) where a few members were "mechanical" representing some motor interests.

I have said before, "Hazardous location classification is not rocket science". Any engineer (no matter what discipline) with an ABET sanctioned degree and capable of passing the EIT exam has the ample ability to learn how. As a matter of fact, a few members of all three TCs have neither an ABET degree nor an EIT. Again, almost without exception, I still believed they were well qualified. The lone exception was a CMP14 member who shouldn't have been on the Panel in the first place.

Both NFPA 497 and API RP 500 have sections outlining the recommended process for developing the Section 500.4(A) "proper documentation". It is definitely a collaborative activity, but all that is actually needed is the process flow diagrams, flow stream material balances and an accurate plot plan. You often don't even need that much for installations within the scopes of Articles 511 to 516. ​