FISCO I.S. and non FISCO I.S. instruments on one segment

[Saulius]

Hello,
I am from Oil Refinery Instrumentation shop. We are starting our first Foundation fieldbus project. It will be LPG tank farm. We have ordered K-tek AT100 level transmitters and Emerson 3051S presure transmiters with foundation fieldbus. K-tek's has Atex I.S. EE x ia IIB T4 certification. Emerson pressure transmitters has Atex FISCO intrinsic Safety certification. I have several questions.
Can they to be connected on one I.S. segment?
Can non FISCO, but I.S. instruments to be conected to FISCO certified barriers such like Smar SB312-LP or MTL 9122-IS FISCO power supply?
Can device with saftey parameters of Ui<=36VDC, Ii<=200mA, Ci=15nF, Li<=10mikroH, Pi<=1W be connected to Pepperl-Fuchs field barrier F2D0-FB-Ex4.CG. In barriers Ex certificate written that device hazardous area should have capacitance of <=5nF. So it looks like it can not be connected with this type of barrier. Can you comment.

Thank You in Advance
Saulius Zilinskas

[IanVerhappen]

As I understand it FISCO devices can be connected to IS networks but not the other way around. This is mainly because of the capacitance restrictions imposed by FISCO.

My suggestion to you relative to the P+F barrier usage is to contact P+F directly. A good person I know is Andreas Agostin at aagostin@sg.pepperl-fuchs.com or Bernd Schuessler BSCHUESSLER@us.pepperl-fuchs.com.

Please post the resolution to your question once you get it from these folks.

Ian

[jberge]

If you use a FISCO barrier all the connected devices must be FISCO certified. This will be stated in the approval. To get FISCO approved the device must first of all have Capacitance < 5 nF and Inductance < 10 uH. Also note that the device must be able to handle the output power that the barrier may worst case provide. Some FISCO barriers provide as much as 2 W for IIC, others are limited to 1.2 W. If your barrier provides 2 W your devices must handle more.

Jonas

Hello,
I am from Oil Refinery Instrumentation shop. We are starting our first Foundation fieldbus project. It will be LPG tank farm. We have ordered K-tek AT100 level transmitters and Emerson 3051S presure transmiters with foundation fieldbus. K-tek's has Atex I.S. EE x ia IIB T4 certification. Emerson pressure transmitters has Atex FISCO intrinsic Safety certification. I have several questions.
Can they to be connected on one I.S. segment?
Can non FISCO, but I.S. instruments to be conected to FISCO certified barriers such like Smar SB312-LP or MTL 9122-IS FISCO power supply?
Can device with saftey parameters of Ui<=36VDC, Ii<=200mA, Ci=15nF, Li<=10mikroH, Pi<=1W be connected to Pepperl-Fuchs field barrier F2D0-FB-Ex4.CG. In barriers Ex certificate written that device hazardous area should have capacitance of <=5nF. So it looks like it can not be connected with this type of barrier. Can you comment.

Thank You in Advance
Saulius Zilinskas

[Saulius]

Dear Saulius,
K-tek AT100 does not show whether the ATEX approval is according with the FISCO concept or not. So I assume it is not FISCO compliant, this means that is an Entity device. "Entity" stands for "regular Ex i".
FISCO devices also come with Ex i parameters, like Ci, Li, U0 etc.
Hence, you can connect FISCO devices together with non-FISCO (=Entity) devices to a non-FISCO (=Entity) Fieldbus network.

If you have a FISCO supply, you can ONLY connect FISCO devices to it, as the FISCO supply does not allow any external inductivities or capacitances. But Entity devices usually have a Ci and Li >0, hence they are not allowed to be connected. Also, the certificate of a FISCO supply says that only FISCO certified devices can be connected.
The FieldBarrier is universal: The main bus cable (trunk) is not Ex i (it is a normal supply and the cable connection at the FieldBarrier is Ex e).
The outputs of the FieldBarrier allow connection of both FISCO and Entity devices. Of course, in such a case, the instruments must be Ex i.
You example with Ui<36V etc, is it an Ex i device? Otherwise, you con not connect it, at least if you want to put it into the hazardous area. If you have only safe area, it is ok. Only thing is, your instrument may not work then, as it may require a higher operating voltage as usual (usual means that the device operates at 9V or more: the FieldBarrier delivers 10V).

For the 5nF in case of Entity, I am checking with Germany whether the certificate is accurate or whether that was a spelling mistake.
I will get back to you latest Wednesday.
Best regards
Andreas Agostin

Product Manager
Process Automation Division
Pepperl + Fuchs Pte Ltd
18 Ayer Rajah Crescent
P+F Building
Singapore 139942
Tel : +65 67 79 90 91 Ext: 439
Direct : +65 67 77 05 28
Fax: +65 68 73 16 37
<mailto:aagostin@sg.pepperl-fuchs.com>
Fieldbus: www.fieldconnex.info
General: www.pepperl-fuchs.com

Have a nice day!

[Saulius]

Here is Andreas Agostin replay:
Hello Saulius,
concerning the 5nF, my suspection was right. The initial certificate is misleading in this point. I already have in hand the first ammendmend to the certificate, but only in German language.
I attached it for your reference, and you will notice that the headlines of this section looks different. Page four now shows the Entity model, and there are values listed for IIC and IIB gas group.
This is how it should look like, and that means that the respective section in the initial certificate did actually not fit to the Entity model. It related to an obsolete FISCO approach in mid 1990s.

According to the ammendment, you can connect up to 355nF in IIC (note that you have to consider the cable capacitance in an Entity environment). The inner capacitance Ci of the FieldBarrier is already included in this value.
The ammendment is signed in december, the translation should be available soon, maybe in 2 to 4 weeks time.
I hope this is good news for you.
I would be happy if you see a chance of using the FieldBarrier; we have a highly-reliable power source avaiable as well, to enable long cable lengths and to provide high power into the field.
If you require further assistance, please contact me again or any of the P+F staff.

Best regards,
Andreas

Andreas Agostin
Product Manager
Process Automation Division
Pepperl + Fuchs Pte Ltd
18 Ayer Rajah Crescent
P+F Building
Singapore 139942
Tel : +65 67 79 90 91 Ext: 439
Direct : +65 67 77 05 28
Fax: +65 68 73 16 37
<mailto:aagostin@sg.pepperl-fuchs.com>
Fieldbus: www.fieldconnex.info
General: www.pepperl-fuchs.com

Have a nice day!

[Saulius]

Here is my conversation with Mr. Bernd Schuessler I hope it can be usefull.

Hello Mr Zilinskas,

Yes you are right! I'm sorry but I was so focused on the capacitance and inductance that I missed the Imax!! Based on that you cannot use the FieldBarrier with your device. The FieldBarrier and most other barriers are designed based on the FF standard recommended practices for devices (I believe it was 30V, 250mA, 5nF and 20uH). Interesting enough, your device does not follow these recommendations.

At this point I can only offer you our IS power repeater (KLD2-PR-EX1.IEC). It would work with your device!

Sorry for the confusion!
Best Regards,
Bernd
__________________________
Bernd Schuessler
Product Manager, Bus Systems
Pepperl+Fuchs, Inc.
Twinsburg, OH
Phone: (330) 486-0199
Mobile: (216) 570-0804
www.am.pepperl-fuchs.com

-----Original Message-----
From: Saulius Žilinskas [mailto:Saulius.Zilinskas@nafta.lt]
Sent: Monday, January 26, 2004 10:03 AM
To: Schuessler, Bernd
Subject: RE: Applying IS for fieldbus

Dear Mr Schuessler,
Thank you for your answers. Concerning suitability of P+F FieldBarrier (F2D0-FB-EX4) can you explain more in detail. According Entity Aproval Imax(AT100 has Ii<=200mA)>=Isc(FieldBarrier Imax=248mA?). So if we are connecting one device we are not satisfying this requirement. As I understand we should connect more devices to satisfy current requirement. please comment. Also about pacity and inductivity characteristics you have provided in your answer (Co=0.478 uF (groups A,B), Lo=0.4mH) can you give me source of it, in EC type examination certificate provided in www.pepperl-fuchs.com site there is different values provided please find attached. Please comment.

Best Regards

Saulius Zilinskas

-----Original Message-----
From: Schuessler, Bernd [mailto:BSCHUESSLER@us.pepperl-fuchs.com]
Sent: Monday, January 26, 2004 4:44 PM
To: Saulius Žilinskas
Cc: Brickner, Marty
Subject: RE: Applying IS for fieldbus

Dear Mr. Zilinskas,

Thank you for you questions. Please find my answers below in "blue".
Feel free to contact me directly if you have ant further questions.
Best Regards,
Bernd Schuessler
___________________________

Bernd Schuessler
Product Manager, Bus Systems
Pepperl+Fuchs, Inc.
Twinsburg, OH
Phone: (330) 486-0199
Mobile: (216) 570-0804
www.am.pepperl-fuchs.com

-----Original Message-----
From: Saulius Žilinskas [mailto:Saulius.Zilinskas@nafta.lt]
Sent: Monday, January 26, 2004 3:28 AM
To: BSCHUESSLER@us.pepperl-fuchs.com
Subject: Applying IS for fieldbus

Dear Mr. Bernd Schuessler,
I have got your e-mail from Mr. Ian Verhappen in FF forum. And I hope you will have time answer to my questions. I am from Oil Refinery Instrumentation shop. We are starting our first Foundation fieldbus project. It will be LPG tank farm. We have ordered K-tek AT100 level transmitters and Emerson 3051S pressure transmitters with foundation fieldbus. K-tek's has Atex I.S. EE x ia IIB T4 certification. Emerson pressure transmitters has Atex FISCO intrinsic Safety certification. I have several questions.
Can they to be connected on one I.S. segment?

If you are using the Pepperl+Fuchs FieldBarrier (F2D0-FB-EX4) the answer is yes! Our FieldBarrier allows the connection of either entity devices or FISCO devices! The FieldBarrier also supports a non-IS trunk connection, which allows you to connect the maximum number of devices to you segment. FieldBarrier basically combines the features of a Segment Protector (short circuit protected junction box) and an IS barrier in a field mountable package. The trunk can be non-IS since the trunk and spurs are galvanically isolated! This enables you to just use a general-purpose power supply to power your segment. Using a general purpose Fieldbus power supply also enables you put the maximum number of devices on your segment.

I attached the FieldBarrier data sheet for your reference. You can also go to www.fieldconnex.info for more information.

Can non FISCO, but I.S. instruments to be connected to FISCO certified barriers such like Smar SB312-LP or MTL 9122-IS FISCO power supply?

That depends on their control drawings. Like I mentioned above, our P+F FieldBarrier allows the connection of both, IS and FISCO devices. When using the FieldBarrier, there is no need to use a special IS or FISCO power supply! You can use a simple and highly reliable power conditioner (KLD2-PC-1.1.IEC) with redundant or simplex power feed modules. They give you up to 1A for your segment and are very inexpensive ($325 US LIST). Based on a passive design they have up to 5000 years MTBF.

Can device with safety parameters of Ui<=36VDC, Ii<=200mA, Ci=15nF, Li<=10mikroH, Pi<=1W be connected to Pepperl-Fuchs field barrier F2D0-FB-Ex4.CG. In barriers Ex certificate written that each device in hazardous area should have capacitance of <=5nF. So it looks like it can not be connected with this type of barrier. Can you comment.

Yes you can connect this device to our FieldBarrier! The actual entity parameters of our FieldBarrier (F2D0-FB-EX4) are:
Voc=15.75 VDC, Isc=247.7mA, Pmax= 975.34 mW, Co=0.478 uF (groups A,B), Lo=0.4mH
Hopefully I could answer you questions. Let me know if you need anything else.

Thank you in advance.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Saulius Zilinskas
Engineer of Design section
Instrumentation shop
Oil Refinery "Mazeikiu Nafta"
Phone: +370 443 92669
Fax: +370 443 92701
e-mail:sauliusz@nafta.lt
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[Mike ONeill]

Back to the original question of interfacing Entity & FISCO devices together in the same segment; why bother if you can get all the devices you need with Entity approvals and an I.S. power supply that can drive as many as you need in that segment? FISCO is a terrific attempt to overcome conventional I.S. design restrictions, but Hawke's RM100 system drives 350mA per I.S. segment and can connect FF816 devices in any gas group and any Zone/Division.
Even the FISCO approach of considering worst case cable parameters so that any cable length can be safe is matched by the freedom to use any length of Type A cable with capacitance less than 200pF/km and L/R or less than 30uH/Ohm (Ohm's law restrictions notwithstanding).
The issue of the low Imax value is also similar to that of the Emerson DVC5000, which has an Entity Parameter of 216mA i.e. not suitable for I.S. interfaces designed to match FF816 devices (24V/250mA/1.2W).
Hawke have a certificate for Hawke I.S. interfaces to be compatible with the DVC5000, and where an OEM has no objection, we can usually derive a compatible certificate for most things.

[Peter]

MTL offers a low cost "spur connector" for just this purpose. Both IIC and IIB versions are available. Part number 9322-SC (IIB) or 9321-SC (IIC)

Peter Inns

Hello,
I am from Oil Refinery Instrumentation shop. We are starting our first Foundation fieldbus project. It will be LPG tank farm. We have ordered K-tek AT100 level transmitters and Emerson 3051S presure transmiters with foundation fieldbus. K-tek's has Atex I.S. EE x ia IIB T4 certification. Emerson pressure transmitters has Atex FISCO intrinsic Safety certification. I have several questions.
Can they to be connected on one I.S. segment?
Can non FISCO, but I.S. instruments to be conected to FISCO certified barriers such like Smar SB312-LP or MTL 9122-IS FISCO power supply?
Can device with saftey parameters of Ui<=36VDC, Ii<=200mA, Ci=15nF, Li<=10mikroH, Pi<=1W be connected to Pepperl-Fuchs field barrier F2D0-FB-Ex4.CG. In barriers Ex certificate written that device hazardous area should have capacitance of <=5nF. So it looks like it can not be connected with this type of barrier. Can you comment.

Thank You in Advance
Saulius Zilinskas
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