Mar 11, 2019

By William (Bill) Burr

The Code is a comprehensive document. Sometimes it can seem quite daunting to quickly find the information you need. This series of articles provides a guide to help users find their way through this critical document. This is not intended to replace the notes in Appendix B or the explanations of individual requirements contained in the CEC Handbook** but will hopefully provide some help in navigating, while reading the code. The 24th Edition of the CE-C, Part I, (C22.1-18)* is now available from CSA Group.

In this article: Annex J18, Part B. Annex J18 is optionally permitted for use in additions, modifications, renovations or operation and maintenance of existing facilities employing the Division system of classification. The rules of Annex J18 are normative (mandatory) where used and amend or supplement other requirements of the code. Additional informative (non-mandatory) information is contained in Annex JB. Due to the size of this annex, it is being discussed in multiple parts. This is Part B. Part A appeared in the February 12 issue of EIN.

Annex J18 is divided into four parts — General, Class I, Class II and Class III locations.

Class I Division I locations

Rules J18-100 to J18-128 apply to installations in Class I, Division 1 locations

Rule J18-100 requires that equipment installed in a Class I, Division 1 location be in accordance with Table 18.

Rule J18-102 requires that

• transformers and electrical capacitors that do not contain a flammable liquid be installed in electrical equipment as above or in compliance with Rule J18-100

    • transformers and electrical capacitors containing a flammable liquid be installed in electrical equipment vaults in accordance with Rules 26-350 to 26-356, and have
        ◦ ventilation to ensure the continuous removal of hazardous gases or vapours,
        ◦ vent openings or vent ducts leading to a safe location outside the building containing the vault,
        ◦ vent openings and vent ducts with enough area to relieve pressure caused by explosions within the vault,
        ◦ every portion of a vent duct within the building constructed of reinforced concrete, and
        ◦ no door or other connecting opening between the vault and the hazardous area.

Rule J18-104 requires meters, instruments, and relays, including kilowatt-hour meters, instrument transformers, and resistors, rectifiers, and thermionic tubes, be located outside the Class I, Division 1 hazardous location or comply with Rule J18-100.

Rule J18-106 outlines wiring methods, in Class I, Division 1 locations and requires

• threaded rigid metal conduit or hazardous location cables with associated cable glands complying with Rule J18-100

• explosion-proof boxes, fittings, and joints threaded for connection to conduit and cable glands

• threaded joints having at least five fully engaged threads, and no running threads

• cables installed and supported to avoid tensile stress at the cable glands

• explosion-proof type flexible fittings be used where necessary for flexible connections at motor terminals and similar places

• intrinsically safe equipment and associated circuits designed and installed as intrinsically safe “i” or “ia” be as specified in Rule J18-064

Rule J18-108 specifies the requirements for sealing in Class I, Division 1 locations and requires that

• conduit seals be installed in conduit systems where

◦ the conduit enters an explosion-proof enclosure containing devices that may produce arcs, sparks, high temperatures, or is 53 trade size or larger housing terminals, splices, or taps and be located as close as practicable up 450 mm from the enclosure

◦ the conduit leaves the Class I, Division 1 location with no box, coupling, or fitting in the run between the seal and the point at which the conduit leaves the location, except that a rigid unbroken conduit that passes completely through a Class I, Division 1 area, with no fittings less than 300 mm beyond each boundary, does not need to be sealed, provided the termination points are in non-hazardous areas

◦ the conduit enters an enclosure that is not required to be explosion-proof, except that a seal is not required where an unbroken and continuous run of conduit connects two enclosures not required to be explosion-proof

• only explosion-proof unions, couplings, reducers, and elbows that are not larger than the trade size of the conduit be used between the sealing fitting and an explosion-proof enclosure

• cable seals be provided in a cable system where the cable enters an enclosure required to be explosion-proof; or the cable first terminates after entering the Division 1 area

• where secondary seals, cable seals, or conduit seals are required, they conform to the following:

◦ the seal be made in a field-installed sealing fitting or cable gland that is accessible and complies with Rule J18-100; or in a sealing fitting provided as part of an enclosure, marked to indicate that such a seal is provided

◦ no splices and taps be made in fittings intended only for sealing nor fill fittings with splices, or taps are made with compound

◦ prevent accumulation or permit periodic draining of liquid or condensed vapour within enclosures for control equipment, raceway systems, and motors or generators provided at the time of manufacture as an integral part of the machine

• runs of cables, each having a continuous sheath, either metal or non-metal, may pass through a Class I, Division 1 location without seals, and

• cables that do not have a continuous sheath, either metal or non-metal, be sealed at the boundary of the Division 1 location.

Rule J18-110 requires that switches, motor controllers, circuit breakers, and fuses including push buttons, relays, and similar devices in Class I, Division 1 locations be provided with enclosures complying with Rule J18-100.

Rule J18-112 requires that transformers, impedance coils, and resistors located in a Class I, Division 1 used in conjunction with control equipment for motors, generators, and appliances, and any associated switching mechanism comply with Rule J18-100.

Rule J18-114 requires that motors, generators, and other rotating electrical machines comply with Rule J18-100.

Rule J18-116 requires that Ignition systems for gas turbines comply with Rule J18-100.

Rule J18-118 requires that

• luminaires and portable lighting be complete assemblies marked for use in Class I locations and have the maximum wattage clearly marked

• luminaires intended for portable use shall be complete assemblies

• each luminaire be protected against physical damage by a suitable guard or by location

• pendant luminaires be suspended by and supplied through threaded rigid conduit stems, and threaded joints be provided with set screws or other effective means to prevent loosening, and for stems longer than 300 mm, provided with permanent and effective bracing against lateral displacement at a level not more than 300 mm above the lower end of the stem, or flexibility in the form of a fitting or flexible connector in compliance with Rule J18-100 situated not more than 300 mm from the point of attachment

• luminaires be supported by boxes, box assemblies, and fittings in accordance with Rule J18-100.

Rule J18-120 requires that portable and fixed utilization equipment, including electrically heated and motor-driven equipment, comply with Rule J18-100, and that ground fault protection be provided to de-energize all normally ungrounded conductors of an electric heat tracing cable set, with the ground fault trip setting adjusted to allow normal operation of the heater.

Rule J18-122 requires that

• flexible cords be used only for connection between a portable lamp, or other portable utilization equipment, and the fixed portion of its supply circuit and, be of the extra-hard-usage type, contain, a bonding conductor; and provided with glands marked for the class and group where the flexible cord enters a box, fitting, or enclosure of the explosion-proof type

• flexible cord meeting the above requirements and protected from damage by location or by a suitable guard can also be used where fixed wiring methods cannot provide the degree of movement for fixed and mobile electrical utilization equipment

Rule J18-124 specifies receptacles and attachment plugs be of the type providing for connection to the bonding conductor of the flexible cord and shall comply with Rule J18-100.

Rule J18-126 requires where condensed vapours or liquids may collect on or come in contact with the insulation on conductors, such insulation be of a type intended for use under such conditions, or the insulation be protected by a sheath of lead or by other means intended for the purpose.

Rule J18-128 requires that signal, alarm, remote control, and communication systems apparatus and equipment comply with Rule J18-100; and all wiring comply with Rules J18-106 and J18-108.

Class I, Division 2 Locations

Rules J18-150 to J18-160 apply to installations in Class I, Division 2 locations

Rule J18-150 requires equipment installed in a Class I, Division 2 location be in accordance with Table 18 and marked accordingly and allows

• transformers, capacitors, solenoids, and other windings that do not incorporate sliding or make-and-break contacts, heat-producing resistance devices, and arcing or spark-producing components

• conduit and cables as specified in Rule J18-152 (1)

• non-explosion-proof or non-flameproof enclosures housing:

◦ non-arcing connections and connecting devices such as joints, splices, terminals, and terminal blocks, switches, controllers, and circuit breakers meeting the requirements as above

◦ unfused isolating switches that are interlocked with associated current-interrupting devices that they cannot be opened under load, or

◦ not more than ten sets of enclosed fuses, or circuit breakers supplying fixed lighting and not used as switches for the normal operation of the lamps

• for the protection of motors, appliances, and luminaires

◦ a standard plug or cartridge fuse placed within an explosion-proof or flameproof enclosure

◦ a fuse installed within a non-explosion-proof or non-flameproof enclosure, provided that the operating element of the fuse is immersed in oil or other suitable liquid, or enclosed within a hermetically sealed chamber, or

◦ a fuse installed within a non-explosion-proof or non-flameproof enclosure, provided that the fuse is a non-indicating, filled, current-limiting type, or an indicating, filled, current-limiting type, constructed in a manner that the blown fuse indication does not cause the fuse body to be penetrated;,and

◦ motors, generators, and other rotating electrical machines of the open or non-explosion-proof type that do not incorporate arcing, sparking, or heat-producing components except as permitted above, or arcing, sparking, or heat-producing components that comply with Rule J18-100.

The machines referred to are permitted to contain anti-condensation heaters suitable for non-hazardous locations, if they

    • do not use arcing or sparking components
    • do not use temperature-limiting controls
    • comply with Rule J18-054 under normal operating conditions
    • are marked on a separate nameplate on the machine with the maximum surface temperature of the heater in degrees Celsius, or a temperature code that indicates the maximum surface temperature

Rule J18-152 outlines wiring methods for installations in Class I, Division 2 locations and requires that

• wiring methods be:

◦ threaded metal conduit

◦ hazardous location cables

◦ Type TC cable, installed in cable tray in accordance with Rule 12-2202

◦ armoured cable with overall non-metallic jacket, such as TECK90, ACWU90, copper-sheathed RC90, or aluminum sheath RA90

◦ control and instrumentation cables with an interlocking metallic armour and a continuous jacket in control circuits (Type ACIC)

◦ Type CIC cable (non-armoured control and instrumentation cable) installed in cable tray in accordance with the Rule 12-2202 (2), where the voltage rating of the cable is not less than 300 V, the circuit voltage is 150 V or less, and the circuit current is 5 A or less

◦ rigid RTRC conduit Type XW, provided that associated boxes, fittings, and joints are marked with the suffix “–XW”, and the installation is performed in industrial establishments that are not accessible to the public and where only qualified persons service the installation

◦ intrinsically safe or non-incendive wiring circuits installed in accordance with Rule J18-064, or

◦ liquid-tight flexible metal conduit and connectors, marked for heavy duty;

• explosion-proof or flameproof boxes, fittings, and joints be threaded for connection to conduit and cable glands

• threaded joints that are required to be explosion-proof or flameproof be either tapered or straight and have tapered threads with at least five fully engaged threads, and not use running threads, or straight threads in Groups IIA and IIB atmospheres have at least five fully engaged threads; and straight threads in Group IIC atmospheres, have at least eight fully engaged threads

• where thread forms differ between the equipment and the wiring system, adapters in accordance with Rule J18-150 shall be used

• cables be installed and supported to avoid tensile stress at the cable glands

• boxes, fittings, and joints need not be explosion-proof or flameproof, except as required by the Rules in this Section

• cable glands be compatible with the degree of ingress protection and explosion protection provided by the enclosure that the cable enters, where the area classification and environmental conditions require these degrees of protection.

Rule J18-154 specifies the requirements for sealing in Class I, Division 2 locations and requires that:

• conduit seals be provided in a conduit system where:

◦ the conduit enters an enclosure that is required to be explosion-proof or flameproof and be located as close as practicable to the enclosure, or as marked on the enclosure, but not farther than 450 mm from the enclosure

◦ the conduit leaves the Class I, Division 2 location with no box, coupling, or fitting in the conduit run between the seal and the point at which the conduit leaves the location, except that a rigid unbroken conduit that passes completely through a Class I, Division 2 area, with no fittings less than 300 mm beyond each boundary, need not be sealed, if the termination points of the unbroken conduit are in non-hazardous areas, or

◦ the conduit leaves a Class I, Division 2 location outdoors, in which case the seal may be located more than 300 mm beyond the Class I, Division 2 boundary, if it is located on the conduit before the conduit enters an enclosure or building

• only explosion-proof unions, couplings, reducers, and elbows that are not larger than the trade size of the conduit be permitted between the sealing fitting and an explosion-proof or flameproof enclosure

• cable seals be provided in a cable system where the cable enters an enclosure required to be explosion-proof or flameproof, or the cable enters an enclosure not required to be explosion-proof or flameproof, and the other end of the cable terminates in a non-hazardous location in which a negative atmospheric pressure greater than 0.2 kPa exists

• where a run of conduit enters an enclosure that is required to be explosion-proof or flameproof, every part of the conduit from the seal to that enclosure comply with Rule J18-106

• runs of cables, each having a continuous sheath, either metal or non-metal, may pass through a Class I, Division 2 location without seals

• cables that do not have a continuous sheath, either metal or non-metal, be sealed at the boundary of the Division 2 location

• where seals are required, Rule J18-108 (4) applies

Rule J18-156 requires that

• luminaires be protected from physical damage by suitable guards or by location

• pendant luminaires shall be suspended by threaded rigid conduit stems or other means specified by the manufacturer

• where suspended pendant luminaires are by threaded rigid conduit stems longer than 300 mm they be provided with permanent and effective bracing against lateral displacement at a level up to 300 mm above the lower end of the stem, or flexibility in the form of a suitable fitting or flexible connector located up to 300 mm from the point of attachment

• portable lamps comply with Rule J18-118 (1) and (2)

Rule J18-158 states that the installation of fixed or portable electrically heated equipment in Class I, Division 2 locations comply with Rule J18-100.

Rule J18-160 governs the use of flexible cords in Class I, Division 2 locations and specifies:

• flexible cords may be used for connection between permanently mounted luminaires, portable lamps, or other portable equipment and supply circuits and be extra-hard-usage type, contain a bonding conductor, and be provided with a sealing gland where entering an explosion-proof fitting or an enclosure;

• flexible cord may be used for parts of the circuit needing a degree of movement for fixed and mobile utilization equipment providing meets the above requirements and is protected from damage by location or by a suitable guard.

In the next instalment, we will be discussing Part C of Annex J18 of Appendix J, Class II locations

* The source for this series of articles is the Canadian Electrical Code, Part I, (C22.1-18) published by CSA.

** Note the CEC Handbook is also published by CSA.

William (Bill) Burr is the former Chair of the Canadian Advisory Council on Electrical Safety (CACES), former Director of Electrical and Elevator Safety for the Province of BC, and former Director of Electrical and Gas Standards Development and former Director of Conformity Assessment at CSA Group. Bill can be reached at Burr and Associates Consulting billburr@gmail.com.