termination fittings listed for the
application.
FPN: See 727.4 and 727.5 for restrictions on use of
Type ITC cable.

(d) Type MI cable with termination fittings listed for Class I, Zone 1 or Division 1 locations. Type MI cable shall be installed and supported in a manner to avoid tensile

stress at the termination fittings.

(e) Threaded rigid metal conduit, or threaded steel

intermediate metal conduit.

(f) Type PVC conduit and Type RTRC conduit shall be permitted where encased in a concrete envelope a minimum of 50 mm (2 in.) thick and provided with not less than 600 mm (24 in.) of cover measured from the top of the conduit to grade. Threaded rigid metal conduit or threaded steel intermediate metal conduit shall be used for the last 600 mm (24 in.) of the underground run to emergence or to the point of connection to the aboveground raceway. An equipment grounding conductor shall be included to provide for electrical continuity of the raceway system and for grounding of non-current-carrying metal parts.

(2) Flexible Connections. Where necessary to employ flexible connections, flexible fittings listed for Class I, Zone 1 or Division 1 locations or flexible cord in accordance with the provisions of 505.17 shall be permitted.

(C) Class I, Zone 2.

(1) General. In Class I, Zone 2 locations, the wiring meth- ods in (C)(1)(a) through (C)(1)(h) shall be permitted.

(a) All wiring methods permitted by 505.15(B).

(b) Types MI, MC, MV, or TC cable with termination

fittings, or in cable tray systems and installed in a
manner to avoid tensile stress at the termination
fittings. Single conductor Type MV cables shall be
shielded or metallic-armored.

(c) Type ITC cable as permitted in 727.4.

(d) Type PLTC cable in accordance with the

provisions of Article 725, or in cable tray systems. PLTC
shall be installed in a manner to avoid tensile stress at
the termination fittings.

(e) Enclosed gasketed busways, enclosed gasketed

wireways.

(f) Threaded rigid metal conduit, threaded steel

intermediate metal conduit.

(g) In industrial establishments with restricted public

access where the conditions of maintenance and
supervision ensure that only qualified persons service the

installation and where metallic conduit does not provide

sufficient corrosion resistance, reinforced thermosetting

resin conduit (RTRC), factory elbows, and associated

fittings, all marked with the suffix -XW, and Schedule 80

PVC conduit, factory elbows, and associated fittings shall

be permitted. Where seals are required for boundary

conditions as defined in 505.16(C)(1)(b), the Zone 1

wiring method shall extend into the Zone 2 area to the

seal, which shall be located on the Zone 2 side of the

Zone 1-Zone 2 boundary.

(h) Nonincendive field wiring shall be permitted using any of the wiring methods permitted for unclassified locations. Nonincendive field wiring systems shall be installed in accordance with the control drawing(s). Simple apparatus, not shown on the control drawing,
shall be permitted in a nonincendive field wiring circuit, provided the simple apparatus does not interconnect the nonincendive field wiring circuit to any other circuit.
FPN: Simple apparatus is defined in 504.2.
Separate nonincendive field wiring circuits shall be