Special Occupancies, Equipment, Motors, and Signaling

Class I covers flammable gases/vapors, Class II combustible dust, Class III ignitable fibers/flyings.

Division 1 means the hazard exists under normal conditions; Division 2 under abnormal conditions.

Seals are required within 18 in of enclosures containing arcing devices in Class I, Division 1.

Approved wiring methods (threaded RMC, Type MC with listed fittings) are required in classified areas.

General care patient beds require at least 8 receptacles; critical care beds at least 14.

Pool equipotential bonding uses a solid copper conductor no smaller than #8 AWG.

A dwelling pool receptacle must be 6-20 ft from the inside pool wall and GFCI protected.

Underwater luminaires must be GFCI protected unless operating at 15 V or less.

Motor disconnecting means must be rated at least 115% of the motor full-load current.

Air-conditioning conductors are sized to the marked minimum circuit ampacity (MCA); the breaker follows the maximum overcurrent protection (MOCP).

Single motor-compressor conductors are sized at 125% of rated-load or branch-circuit selection current.

Compressor branch-circuit short-circuit protection may be up to 175% (225% where needed to start).

Class 2 circuits are inherently limited low-energy circuits used for control and signaling.

Power-limited fire alarm cables carry the FPL family markings (FPL/FPLR/FPLP).

Article 411 low-voltage lighting is limited to 30 V AC and supplied through a listed power source.