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Code Requirements for Flexible Process Wiring Products Hazardous Locations

TURCK 7/20/2018

Hazardous Locations

Even more value can be derived from the TURCK process wiring system in hazardous locations. The system is now FM approved for use in Class I, Divisions 1 and 2 when installed per TURCK drawing QCF-00147 and CSA certified when installed per TURCK control drawing Ni-2.404. Contact TURCK for a copy of the approval documents or visit TURCK website.

Intrinsically Safe Circuits

TURCK Code Requirements for Flexible Process Wiring Products Hazardous Locations

Intrinsically safe circuits may be wired using any of the wiring methods suitable for unclassified locations. The use of connectors is allowed as intrinsically safe circuits are safe against faults, including opening, shorting or grounding. The same requirements for mechanical protection and length limitations apply as in nonhazardous locations.

Nonincendive Equipment

TURCK Code Requirements for Flexible Process Wiring Products Hazardous Locations

FM:
ITC cable is a recognized Division 2 wiring method. NEC in Article 501.10 (B)(1)(5) states "Type ITC cable as permitted in 727.4". This is further reinforced by Article 727.4 (3), which states that ITC cable is permitted "in hazardous locations as permitted in 501.10,...". The same requirements for mechanical protection and length limitations apply as in nonhazardous locations.

CSA:
Canadian installations require the use of specific cable types for non-intrinsically safe circuits in Class I, Division 2 areas. TURCK offers CMX-HL cables for unprotected cable runs and CIC cable (Control and Instrumentation Cable) for cable runs in cable trays.

Process Wiring Products

Quick-disconnects that do not require a tool to disengage are considered "normally arcing". They are not allowed to be used in Division 2 for incendive circuits without additional protection.

TURCK Code Requirements for Flexible Process Wiring Products Hazardous Locations

lokfast guards enable the use of quick-disconnect technology in Class I, Division 2 hazardous locations.

lokfast guards render quick-disconnects not "normally arcing" by:
- Eliminating access to the coupling nut making disconnection impossible.
- Warning the user to disconnect power before removing.
- Requiring a tool for removal.

lokfast guards are available for 7/8-16UN minifast and M12 eurofast molded and field-wireable connectors. Optional M23 multifast home-run connectors with set screw locks also render a connection not "normally arcing".

TURCK Code Requirements for Flexible Process Wiring Products Hazardous Locations

lokfast guards (or integrally locked multifast connectors) on all quick disconnects in Division 2 (Figure 1).

The molded construction of the home-run connector and the gas/vapor tight continuous sheath meet the NEC Article 501-15(E)(2) requirements for cable seals in Division 2.

The same requirements for mechanical protection and length limitations apply as in to nonhazardous locations.

Intrinsic Safety Summary

TURCK Code Requirements for Flexible Process Wiring Products Hazardous Locations

Intrinsically safe circuits do not require additional protection for quick-disconnects. Junction boxes must have FM-approved spacings and entity parameters for intrinsically safe circuits. Boundary seals are not required for this location, as the molded home-run connecter and the gas/vapor tight continuous cable sheath meet the NEC Article 501-15) requirements for cable seals in Class I, Divisions 1 and 2. Requirements for mechanical protection and length limitations are equivalent to nonhazardous locations.

Explosionproof Equipment

TURCK Code Requirements for Flexible Process Wiring Products Hazardous Locations

ITC cable, a recognized Division 2 wiring method, may be used to connect Explosionproof equipment installed in Division 2 when used with an explosionproof feed-through receptacle. The extremely robust receptacle maintains the equipment's explosion containment protection scheme. The external wiring, however, is in Division 2, and can therefore be installed using Division 2 wiring methods.
Explosionproof feed-thru receptacles may also be used to feed intrinsically safe circuits into or out of explosionproof enclosures in Class I, Division 1 hazardous locations.