Class 1 Division 2 - Instrument Power

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Wattman

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I have approx. 25 instruments located in a Class 1 Division 2 area that will receive loop power from an AB1606-XLS240E 24V, 10A DC Power Supply. In looking over the specs, it indicates that it is approved for Class1 Div 2 bal blab la and it meet the requirements of UL1604 which I don?t have access to at this time.

Now the control drawings for the instruments basically just states the power source is from a ?barrier or associated equipment or FM approved associated NI field wiring apparatus?
Does this power supply meet this requirement?

I would ask AB this question but I don?t have time to navigate their complex maze of sales help! I just don?t like paying to ask them a presales question.

This project is basically a copy of a previous phase of the same project, and this power supply is used previous phases, as if it supplies intrinsic safe power to the instruments it powers within the Class 1 Division 2 areas

Is this possible?

What will UL1606 say?

Thanks in advance
Watt
 
In real estate, the catch phrase is "Location, location, location."

In electrical, especially hazardous locations, it's "Detail, detail, detail."

Essentially it comes down to wiring method and enclosures within the "zone". Exposed cable will have to be either NI or IS per control drawing. It may take several control drawings to complete an entire circuit, inclusive of power supply and instrument, whatever is in the "zone". Where not NI or IS, equipment and cable or wiring within permitted enclosures and raceways are not subject to control drawings.

Copying an existing installation is no guarantee of compliance.
 
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rbalex said:
I corrected the reference and here's a link to its scope. It doesn't address IS at all.

It wasn't too difficult to find the relevant AB1606-XLS240E (switch mode power supplies) certifications either. They aren't IS or NI.
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Yes Robert

Thanks for your reply

I had already found the link to the UL 1604 document, but if you will notice that is only a partial of the content, you have to purchase it, to see the whole document

and

Yes I had already seen the spec for the AB power supply, and I assume you seen it is approved for Class 1 Division 2 (TA2), I'm not sure what the TA stands for? or if the Class 1 Division 2 approval means that I can put it in that C1D2 environment in a paper bag, or I can run the only the + and - into a class 1 div 2 area

So with the power supply it - has the approval, does that mean it is a meets the requirement of my control drawing quote "Any approved Associated Apparatus or associated nonincendive field wiring"

My Control drawing states that a barrier is not required for a div 2 location

I have about 80 instruments from 4 different manufactures some of the word meanings are a bit confusing

Watt
 
Wattman said:
Yes Robert

Thanks for your reply

I had already found the link to the UL 1604 document, but if you will notice that is only a partial of the content, you have to purchase it, to see the whole document

and

Yes I had already seen the spec for the AB power supply, and I assume you seen it is approved for Class 1 Division 2 (TA2), I'm not sure what the TA stands for? or if the Class 1 Division 2 approval means that I can put it in that C1D2 environment in a paper bag, or I can run the only the + and - into a class 1 div 2 area

So with the power supply it - has the approval, does that mean it is a meets the requirement of my control drawing quote "Any approved Associated Apparatus or associated nonincendive field wiring"

My Control drawing states that a barrier is not required for a div 2 location

I have about 80 instruments from 4 different manufactures some of the word meanings are a bit confusing

Watt
Click to expand...
First, I want to commend you for attempting to do your own homework. Hazardous (Classified) locations are a prime application for Section 90.1(C) and, up to now, as best they can, Code Making Panel 14(CMP14) avoids making material within their scope "...a design specification or an instruction manual for untrained persons." You appear to be pretty well on your way to becoming a "trained person."

Second, the Scope of a document, in this case UL 1604, sets the boundaries of its application. See Section 1.9 for the application to intrinsically safe methods of protection. The lack of specific reference to nonincendive systems would not necessarily exclude them, but it isn't necessarily inclusive either.

Third, that "(T2A)? is critical to determining whether it is Associated Nonincendive Field Wiring Apparatus or not. Read the definition in Section 500.2 carefully and compare it with Section 500.8(C)(4) and Table 500.8(C). BTW, it irritates me no end when a manufacturer doesn't refer to "Class" with Roman Numerals in its literature.

A paper bag is not a recognized enclosure - in any location. But other "ordinary location" enclosures (Section and Table 110.28[2011 NEC]) are acceptable. See Sections 501.10(B)(4) and 501.105(B).

Edit Add: The T code indicated on the data sheet is T3A.
 
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Application 1 - Example

Application 1 - Example

You seem knowledgeable about the subject - so I will bounce a couple of application questions I have, your way to discuss

Application 1 - Example

Say I have a control valve in a C1D2 area, the valve has a Hart IP mounted directly to it. All I have to do is run 4-20 mA to it from the PLC.

The PLC uses a 1756 AO Card the card is capable of Hart communications via the 4-20 to the valve. The card has a rating that states it has ?FM Approved Equipment for use in Class I Division 2 Group A,B,C,D Hazardous Locations? But the card is in a control panel in a non-Hazardous, only the current loop it going into the C1D2 area. So I don?t use a barrier or anything when I leave the panel

So we run the approved 2 conductor shield cable 1000 ft via cable tray and drop off the tray and continue the last 30ft RMC, sealing the conduit before entering the valve IP.

The ?Control drawing for the IP? indicates the circuit will derive from ? Any approved Associated Apparatus or associated nonincendive field wiring?

Does the AO card meet this requirement?
Is it an "Approved Associated Apparatus?:happyno::happyyes:
I think Yes I'm legal, do you agree?:rant:

Can the cable be treated as an intrinsic cable (no arc or spark) if so I can give spec a outer cable color of light blue, or do I have to keep it black?:lol:
I'm not sure :dunce:

Can the Tec just open the IP and work on it with loop power ON?:jawdrop:
I think he can, but not sure if he legally can?

What do you think? :?
 
Wattman said:
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So we run the approved 2 conductor shield cable 1000 ft via cable tray and drop off the tray and continue the last 30ft RMC, sealing the conduit before entering the valve IP [Why seal it? Is the IP enclosure required to be explosionproof?]

The ?Control drawing for the IP? indicates the circuit will derive from ? Any approved Associated Apparatus or associated nonincendive field wiring?

Does the AO card meet this requirement?
Is it an "Approved Associated Apparatus?
I think Yes I'm legal, do you agree? [I agree.]

Can the cable be treated as an intrinsic cable [No; you have described a nonincendive system, not IS] (no arc or spark) if so I can give spec a outer cable color of light blue, or do I have to keep it black?
I'm not sure

Can the Tec just open the IP and work on it with loop power ON?[No; you have described a nonincendive system, not IS. See the definition of nonincendive equipment. The problem is "normal operating conditions" would not usually include a tech opening the IP.]
I think he can, but not sure if he legally can?

What do you think?
Click to expand...
Nonincendive basically means that the system is incapable of igniting a specified flammable gas?air, vapor?air or dust-air mixture under specified normal operating conditions. ISA has done a marvelous job muddying the issue by dividing up the basic concept into multiple definitions. In fairness, "normal" doesn't necessarily mean "common" or "usual".
 
So we run the approved 2 conductor shield cable 1000 ft via cable tray and drop off the tray and continue the last 30ft RMC, sealing the conduit before entering the valve IP [Why seal it? Is the IP enclosure required to be explosionproof?]

*Well the conduit is open on the end that it picks up the cable from the Cable Tray, so I assume vapor gas could enter the IP. (the chemical starts to vapor at about 150F plant is in the dry ambient temp of say 110F I would think would be common, it was determined by the Insurance company that the project area is C1D2

I have not seen the valve or specs on the actual valve yet, not sure what the enclosure will actually be. I have the manual on the IP electronics and the ?Control Drawing? but it does not indicate a seal on it that I can find, none of the other CD indicate a seal is needed or not. The Control drawing is for all class areas.

So No seal is needed ? so is it No seals are needed on anything because its C1D2 area? (it?s just easier to spec one now, than wish one later)
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Can the cable be treated as an intrinsic cable (no arc or spark) if so I can give spec a outer cable color of light blue, or do I have to keep it black? I'm not sure
[No; you have described a nonincendive system, not IS]

*So just say, the analog output card had been approved C1D1, it would have been a intrinsic circuit and do not have to add a barrier or isolator to the circuit before it left the panel and I could use a light blue cable and route it with my other intrinsic circuits? (meaning the AO had been evaluated under fault conditions and is intrinsic)

The reason I ask is the AO is HART and I do have some intrinsic (NAMUR) circuits within this project
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Can the Tec just open the IP and work on it with loop power ON?I think he can, but not sure if he legally can? What do you think?
[No; you have described a nonincendive system, not IS. See the definition of nonincendive equipment. The problem is "normal operating conditions" would not usually include a tech opening the IP.]

*Is normal condition defined as Process Running or Not Running, Just say the process is not running, but the all the equipment is powered up, the area is C1D2 running or not, tech needs to evaluate the IP operation some what with the enclosure open maybe connect his meter within the circuit. Maybe the area should be sniffed first?
 
Seals are not needed in Class I, Division 2 areas at equipment unless the equipment has an explosion proof enclosure. Just because the equipment is suitable for use in the Class I, Division 2 area does not mean it will have an explosion proof enclosure.
 
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