NI Rating for Class 1 Div 2 E/P Transducer

[gerbonic]

I am currently specing out devices for a project in a Class 1 Div 2 Area. I need a e/p transducer (0-5VDC) and I ran into a device that is specifically IS for Class 1 Div 1 and NI for Class 1 Div 2. I had them send me the certificate and it clearly stats NI for Class 1 Div 2.

The same FM certificate state IS for Class 1 Div 1 and listed a control drawing, but the NI entry on the cert did not have a control drawing.

Having state this does this indicate that this is considered a simple device and needs no control drawing?

If this IS the case then are there any special considerations regarding this device when installed in a class 1 div 2 area?

Do I need to a barrier? I would think not since I have never seen any thing in the NEC or ISA indicating this but I may have missed something.

Is there special wiring considerations other than the having it in its own cable, etc? It will actually be in its own pipe.

What is the ultimate authority deciding what a simple device is?

Thank you

 

[gerbonic]

Here is a stream line question. My device is marked class 1 div 2 NI. There is no control drawing. What special consideration are required in the installation? As previously stated the wiring will have its own cable.

 

[rbalex]

Ever since the ISA gained control of IS and NI systems, it has become more and more difficult to deal with them through the NEC.

Most of the relevant definitions (even for NI) are in Article 504. The E/P transducer is definitely not Simple Apparatus.[504.2]

The lack of an NI control drawing is troubling since it is still a mandatory requirement, Simple Apparatus or not [501.10(B)(3)]

 

[gerbonic]

So I talked to the customer service guy at control air inc and he stated that since the e/p was a two wire device with positive to positive and negative to negative there was no control drawing. The question is how is this FM certified as NI c1d2 then? Does FM have their own set of requirments. The ISA and the NEC definitely seem to not correlate or work together well. I prefer the NEC as it seems more clear cut. I may end up going with explosion proof then and not worry. It's a little harder to go wrong with xp.

 

[Smart $]

If the E/P is C1D1 IS, you can install it IS in C1D2.

Did you look at IS control drawing? It may have optional C1D2 NI installation on it.

 

[rbalex]

So I talked to the C and he stated that since the e/p was a two wire device with positive to positive and negative to negative there was no control drawing. The question is how is this FM certified as NI c1d2 then? Does FM have their own set of requirments. The ISA and the NEC definitely seem to not correlate or work together well. I prefer the NEC as it seems more clear cut. I may end up going with explosion proof then and not worry. It's a little harder to go wrong with xp.

First, I want to acknowledge that Smart $'s response is reasonable; however, the only reason to install either IS or NI is to permit "... using any of the wiring methods permitted for unclassified locations." As long as the wiring method used is recognized in Section 501.10(B)(1) AND the transducer meets the requirements of 501.105(B)(2) and/or (3), there is no reason to worry about control drawings, NI rating or explosionproof enclosures.

The "customer service guy" is incorrect. If, you wanted to use the transducer in an NI application, a control drawing is still a requirement [Section 501.10(B)(3)].

 

[gerbonic]

Thank you all for your replies. It appears there is something fishy is coming from customer service. The fm standard 3611 approval for NI devices also requires a control drawing, so I wonder how they get away with not having a control drawing while maintaining the NI rating on the device? The only control drawing I saw was for IS and it did not address NI wiring at all...