I wonder if non-incendive circuits require a separation from all other circuits in Div.2 area. Intrinsicaly safe circuits must be in a separate raceway. What about non-incendive? Have a bunch of pressure transmitters that are approved per UL1604 (non-incendive)- wonder how many conduits to run - mix them with the rest of signals or in a separate raceway.
Non-incendive components in Class 1 Div.2
- Thread starter alte
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petersonra
Senior Member
- Location
- Northern illinois
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- engineer
Re: Non-incendive components in Class 1 Div.2
The circuits are not non-incendive. The devices are. No special requirements.
The circuits are not non-incendive. The devices are. No special requirements.
- Location
- Mission Viejo, CA
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- Professional Electrical Engineer
Re: Non-incendive components in Class 1 Div.2
What you are describing is nonincendive field wiring:
What you are describing is nonincendive field wiring:
The essential element is: Nonincendive field wiring systems shall be installed in accordance with the control drawing(s).?
The control drawing will generally specify the necessary separation of nonincendive circuits from ?common? light and power circuits because they are usually power-limited circuits similar to those specified in Art 725.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: Non-incendive components in Class 1 Div.2
Bob - when did all this stuff get added to the code?
As a practical matter, does it really change anything?
Bob - when did all this stuff get added to the code?
As a practical matter, does it really change anything?
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Non-incendive components in Class 1 Div.2
It was "officially" introduced in the 2002 Code.
Part of coordinating Divisions and Zones required updating a lot of product standards. The ISA is the US organization dealing with coordinating with the IEC for "Protection Techniques" (Section 500.7) since they represent a broad range of interests, especially manufacturers. (They are classified as a "Manufactures" on the CMP)
Many of the concepts were in place before, like the wiring was often Art 725 installations and then modified to adapt to Classified locations.
As a practical matter, Section 500.4 "documentation" is an OHSA enforcable item and the "Control Drawings" are part of it.
It was "officially" introduced in the 2002 Code.
Part of coordinating Divisions and Zones required updating a lot of product standards. The ISA is the US organization dealing with coordinating with the IEC for "Protection Techniques" (Section 500.7) since they represent a broad range of interests, especially manufacturers. (They are classified as a "Manufactures" on the CMP)
Many of the concepts were in place before, like the wiring was often Art 725 installations and then modified to adapt to Classified locations.
As a practical matter, Section 500.4 "documentation" is an OHSA enforcable item and the "Control Drawings" are part of it.
Re: Non-incendive components in Class 1 Div.2
Bob,
In my case there is no control drawing available. The second part of 501.4(B)(3) calls for "separate non-incendive wiring" to be installed in cables. It really contradicts the first part when any wiring method is allowed, unless in my understanding "separate" is required by the control drawing. On the same note if I have a simple apparatus (i.e. thermocouple) - it is permitted as non-incendive wiring and can be wired using any method permitted in unclassified location and installed together with the rest of 24VDC regular circuits in single conduit.
And by the separate conduit I meant separate non-incendive circuits only (apart from 24VDC low voltage DC circuits). Power and light are obviously in their respective conduits.
The canadian electrical code specifically calls for a separate raceway for non-incendive field wiring only. It seems this is not required in NEC.
Mike
Bob,
In my case there is no control drawing available. The second part of 501.4(B)(3) calls for "separate non-incendive wiring" to be installed in cables. It really contradicts the first part when any wiring method is allowed, unless in my understanding "separate" is required by the control drawing. On the same note if I have a simple apparatus (i.e. thermocouple) - it is permitted as non-incendive wiring and can be wired using any method permitted in unclassified location and installed together with the rest of 24VDC regular circuits in single conduit.
And by the separate conduit I meant separate non-incendive circuits only (apart from 24VDC low voltage DC circuits). Power and light are obviously in their respective conduits.
The canadian electrical code specifically calls for a separate raceway for non-incendive field wiring only. It seems this is not required in NEC.
Mike
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Non-incendive components in Class 1 Div.2
You are leaving me with a big problem here.
The lack of a control drawing means you have to treat the installation as Art 725 circuits which specifies separation. That assumes that the transmitters are indeed Class 2 or 3 power-limited supplies; otherwise, they would be ?ordinary? power installations and separation is simply a design issue with regard to signal conditioning.
Note: the second part of 501.4(B)(3) does NOT call for ?separate nonincendive wiring" to be installed ..., but that ?separate nonincendive field wiring circuits .? The intent is to avoid interconnection between the circuits that may increase the available ignition energy.
You are leaving me with a big problem here.
The lack of a control drawing means you have to treat the installation as Art 725 circuits which specifies separation. That assumes that the transmitters are indeed Class 2 or 3 power-limited supplies; otherwise, they would be ?ordinary? power installations and separation is simply a design issue with regard to signal conditioning.
Note: the second part of 501.4(B)(3) does NOT call for ?separate nonincendive wiring" to be installed ..., but that ?separate nonincendive field wiring circuits .? The intent is to avoid interconnection between the circuits that may increase the available ignition energy.
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