Lesson 3: The requirements for Electrical Installations in Calss I Hazardous (classified) Locations

Type PVC conduit, Type RTRC conduit, and Type HDPE conduit shall be permitted where encased in a concrete envelope a minimum of 50 millimeters (two inches) thick and provided with not less than ? of cover measured from the top of the conduit to grade.

24" 501.10(A)(1)(1)Exception

Totally enclosed motors of the types specified in 501.125(A)(2) or (A)(3) installed in Class I, Division 1 locations shall have no external surface with an operating temperature in degrees Celsius in excess of ? the autoignition temperature of the gas or vapor involved.

80% 501.125(A)

Seals are required in each conduit entry into an enclosure containing apparatus, such as switches, circuit breakers, fuses, relays, or resistors that may produce arcs, sparks, or temperatures that exceed 80% of the ? , in degrees Celsius, of the gas or vapor involved in normal operation.

A. Autoignition temperature 501.15(A)(1)(1)

Enclosures installed in Class I locations, identified for the location, and marked "Leads Factory Sealed," "Factory Sealed," "Seal not Required," or the equivalent, shall not be considered to serve as a seal for another ? enclosure that is required to have a conduit seal.

A. adjacent 501.15(A)(1)(2)

Sealing compound must be used in Type ? cable termination fittings to exclude moisture and other fluids from the cable insulation.

B. MI 501.15

Match the following hazardous locations equipment with the type designator for the equipment.

CPP, CPH, FSQC, APJ

All boxes and fittings installed in a Class I, Division 1 location must be listed for Class I, Division 1 locations.

False (approved) 501.10(A)(3)

Threaded rigid metal conduit, threaded steel intermediate conduit, or electrical metallic conduit is permitted to be used in Class I, Division 1 locations.

False 501.10(A)(1)(1)

Listed 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 are permitted to be installed in all Class I, Division 2

False 501.10(B)(1)(6)

Match the following hazardous locations equipment with the type designator for the equipment.

GFS-1, EFS, EBMC, EIB

Drag and drop the correct sealing fittings (conduit seals) onto the illustration.

See first day handouts. going top to bottom Seal, EFS switch, EYS seal, EZS seal.

Fused or unfused disconnect and isolating switches for transformers or capacitor banks that are not intended to interrupt current in the normal performance of the function for which they are installed shall be permitted to be installed in general-purpose enclosures.

True 501.115(B)(2)

In Class I, Division 2 locations, shielded cables and twisted pair cables installed in required sealing fittings shall not require the removal of the shielding material or separation of the twisted pairs, provided the termination is by an approved means to minimize the entrance of gases or vapors and prevent propagation of flame into the cable core.

True 501.15(E)(1)exception 2

The locknut-bushing and double-locknut types of contacts are not permitted to be used for bonding purposes in Class I, Division 1 or Class I, Division 2 locations.

True 501.30(A)

Where luminaires are pendant mounted in Class I, Division 1 locations, stems longer than ? require permanent and effective bracing against lateral displacement.

a. 12" 501.130(A)(3)

The sealing fitting required to be installed in conduit runs leaving a Class I, Division 2 location shall be permitted to be installed on either side of the boundary within ? of the boundary.

b. 10' 501.15(B)(2)

Transformers and capacitors that do not contain a liquid that will burn may be installed in Class I, Division1 locations where they are installed in vaults complying with 501.100(A)(1) or ? for Class I locations.

b. identified 501.100(A)(2)

Motors installed in Class I, Division 2 locations must be open, non-explosionproof enclosed motors, such as squirrel-cage induction motors without brushes, switching mechanisms, or similar arc-producing devices that are not ? for use in a Class I, Division 2 location.

b. identified 501.125(B)(3)

There shall be no uninsulated exposed parts, such as electrical conductors, buses, terminals, or components, that operate at more than ? ( ? in wet locations) installed in Class I, Division 1 or Class I, Division 2 locations.

c. 30v / 15v 501.25

Where two or more explosionproof enclosures that require conduit seals are connected by nipples or runs of conduit not more than ? long, a single conduit seal in each such nipple connection or run of conduit shall be considered sufficient.

c. 36" 501.15(A)(3)

Flexible cords permitted for process control instruments must not exceed three feet and must be ? for extra-hard usage, or may be hard usage if protected by location.

c. Listed 501.105(B)(6)(2)

Where Type MI cable is used in Class I, Division 1 locations, it shall be installed and supported in a manner to avoid ? at the termination fittings.

c. Tensile stress 501.10(A)(1)(2)

Machines containing motors, generators, and other ? electrical machinery installed in industrial establishments with restricted public access, where conditions of maintenance and supervision ensure that only qualified persons service the installation, may be of a type designed to be submerged in flammable liquids under certain conditions.

c. rotating 501.125(A)(4)

Equipment that is permitted to be installed in general-purpose enclosures in Class I, Division 2 locations shall be permitted to be marked to indicate the temperature class for which it is ? , using the temperature class (T Code) of Table 500.8(C).

d. suitable 501.105(B)(1)

The required enclosures for meters, instruments, and relays in Class I, Division 1 locations include ? enclosures and purged and pressurized enclosures.

explosionproof 501.105(A)

Drag and drop the correct identification for each sealing fitting shown.

refer to day 1 handout EYS, EYSR, EZS, EYD, ESWP

Drag and drop the statement to the arrow that best describes the protection component provided at that point on the luminaire.

see first day handouts

In Class I, Division 1 locations or in Class I, Division 2 locations where boxes, fittings, or enclosures are required to be explosionproof, flexible cords shall be terminated with cord connectors or attachment plugs listed for the location or listed cord connectors installed with seals listed for the location.

true 501.140(B)(4)