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EIABC - November Newsletter 
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Message from the President 


The September issue of “The Inspector” had an announcement about the development of a new EIABC web site. I am very pleased to announce that the new site is now up and running. I would be remiss if I did not thank Rick Porcina for his many years of service to our association as web site manager. Rick has decided to get a little further into retirement and asked us to make other arrangements for the web site management. Many thanks Rick from the board and membership for a job well done.

I think that I would also be remiss if I did not bring up the subject of electrical safety in this message. We think primarily in terms of electrical safety of course, however we need to be constantly aware of safety concerns in general as well. This is a good time of the year to reflect on our successes and also on how we can make improvements in our continuing challenge of helping to provide a safe environment for the people of BC.

The fall season is upon us. On December the 1st we will be holding our Christmas dinner meeting complete with our traditional gift draw and silent auction. Last years donors can be very proud to have played a part in making possible a donation of over $15,000 to the CKNW Orphans Fund. This year, Santa Len is already busy contacting his list of potential donors in an effort to meet and maybe even beat last years donation amount Please come out and support this worthy cause. 

On behalf of the entire board I wish you and your families a safe and joyous festive season and happiness in the new year.

Warm Regards,

Rick May
President
EIABC

November 2014


Inside This Issue


Message from the President
- Rick May

Section 22 of the CE Code
Understanding of confusing requirements

- Ark Tsisserev

EIA Code Article - Nov 2014
- Ted Simmons

 



EIA Executive

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Electrical Inspector’s Association of British Columbia

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B.C., V5C 6N5

Phone: 604-294-4123
Fax: 604-294-4120
Email: info@eiabc.org

Section 22 of the CE Code
-understanding of confusing requirements

 
By Ark Tsisserev, P.Eng.
Ark Tsisserev is an independent electrical fire and safety Ark Tsissserev, P.Eng.consultant. Prior to becoming a consultant, he was an electrical safety regulator / Chief Electrical Inspector for the City of Vancouver . EFS Engineering Solutions Ltd.    ark.tsisserev@efsengineering.ca

Scope of Section 22 applies to the installation of electrical equipment “in locations in which corrosive liquids, vapours, or excessive moisture are likely to be present”

Section 22 also covers installation of electrical equipment in sewage lift and treatment plants.

Areas covered by Section 22 are classified as Category 1 or Category 2 locations, and the Code users should be able to classify the respective areas accordingly based on the definitions of Category 1 or Category 2, and select types of electrical equipment and wiring methods, as appropriate for the established Category.

In addition, sewage lift and treatment plants must be also classified for hazardous areas in accordance with Section 18.

So, at the first glance - everything should be reasonably simple for the purpose of applying appropriate requirements of Section 22. 

However, there appears to be some confusion in respect to application of installation requirements in wet locations in conjunction with the installation requirements in Category 1 locations.

Apparently, there is also a degree of confusion whether a typical sewage lift and treatment plant must be automatically classified as Class I hazardous location.

Let’s deal with a couple of illustrations of such confusion. One traditional example of confusion - is vehicle washing areas in industrial or commercial facilities.

Some Code users are under impression that a typical industrial or commercial vehicle washing area should not be covered by Section 22, as it is not necessarily a Category 1 location, and it is not shown among the examples in the Appendix B Note Table on Rule 22-002. Arguments are made that even if a vehicle washing area should be considered to be “wet location”, the “wet location” is not necessarily a “Category 1” location, and the relevant provisions of Section 22 for Category 1 location are not applicable.

Perhaps, before analyzing the relationship between “wet location” and “Category 1 location”, let’s review the Code definitions in conjunction with this subject.

“Wet location — a location in which liquids may drip, splash, or flow on or against electrical equipment“
“Category 1 — the location is one in which moisture in the form of vapour or liquid is present in quantities that are liable to interfere with the normal operation of electrical equipment, whether the moisture is caused by condensation, the dripping or splashing of liquid, or otherwise“

It should be noted that the NEC offers a more comprehensive definition of “wet location”, and it uses vehicle washing areas as an example of wet location as follows:

“Location, wet. Installation underground or in concrete slabs or masonry in direct contact with the earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations exposed to weather”.

It should be also noted that although definition “Category 1” does not explicitly reference “wet location”, it could be seen from the Category 1 definition that attributes of a typical wet location are already included in the Code definition of Category 1 location. (Category 1 location is such area where moisture or liquid is present in quantities that may interfere with the normal operation of electrical equipment, regardless whether such moisture or liquid is a result of condensation or the result of spaying, splashing or dripping).

Furthermore, Rule 22-200 references “wet locations” in requirements for wiring methods in Category 1 locations.

Therefore, there should be no doubt that electrical equipment in the areas of an industrial or commercial vehicle washing facilities must be covered by the applicable provisions of Rule 22-100 – 22-108, and the wiring methods in the vehicle washing areas must be covered by Rule 22-200.

Of course, the referenced Table in Appendix B represents only some examples (but far from all possible illustrations) of Category 1 Location.
However, there is also no doubt that Appendix B Table on Rule 22-002 could be (and should be) expanded – to include such areas as car/vehicle wash and other similar industrial washing faculties.

Let’s now review provisions of Section 22 regarding areas classification of a sewage lift and treatment plant.

The CE Code offers the following definitions and classification requirements:
“22-702 Special terminology In this Subsection, the following definitions apply:

Continuous positive pressure ventilation — a ventilation system capable of maintaining a positive pressure in a room or area and of changing the air in the room or area at least six times an hour with means for detecting ventilation failure.
Dry well — the location below ground designed to accommodate equipment associated with wastewater pumping and isolated from the wet well location to prevent the migration of gases and vapours into the dry well.
Suitably cut off — an area rendered impermeable and cut off from an adjoining area with no means of liquid, gas, or vapour communication between the areas at atmospheric pressure.
Wet well — the location below ground where the raw sewage is collected and temporarily stored before passing through the lift pumps or being processed in a treatment plant.

22-704 Classification of areas (see Appendix B)
(1) Sewage lift and treatment plants shall be classified for
  • (a) hazardous areas in accordance with Section 18; and
  • (b) corrosive liquids, vapours, or moisture in accordance with this Section.
(2) Wet wells provided with adequate continuous positive pressure ventilation shall be considered Class I, Zone 2.
(3) Except as permitted by Subrule 5(c), all locations below ground suitably cut off from locations in which sewage gases may be present shall be considered Category 1.
(4) All locations in which sewage gases may be present in explosive concentrations shall be considered hazardous areas and Category 2.
(5) The following areas shall be permitted to be classified as ordinary locations:
  • (a) all locations suitably cut off from a Category 2 location and not classified as a Category 1 location;
  • (b) all locations not suitably cut off from a Category 2 location but with adequate continuous positive pressure ventilation; and
  • (c) dry well locations below ground where adequate heating and adequate continuous positive pressure ventilation is installed”
The Code users should be aware that Appendix B Note on Rule 22-704 invites the users to apply NFPA 820 for classification of hazardous areas.

It is interesting to note that the NFPA 820 definitions of “dry well” and “wet well” are bit different (see below):
“3.3.71 Well.
3.3.71.1* Dry Well. The portion of a pumping station designed to provide isolation and shelter or accommodations for controls or equipment associated with pumping of wastewater and designed to completely and permanently exclude wastewater or wastewater-derived atmospheres.
3.3.71.2* Wet Well. The portion of the pumping station that receives and temporarily stores wastewater for the purpose of pumping”.

 

It is also interesting to note that in addition to Rule 22-704, Table 4.2 of NFPA 820 offers very comprehensive criteria for classification of hazardous areas, and that in accordance with specific conditions (i.e. ventilation with at least 6 air changes per hour and pressurization conforming to NFPA 496), dry well locations and other areas that are not suitably cut off from dry well locations (motor rooms, control rooms, etc.) could be classified as ordinary (non-hazardous) locations for the purpose of installation of electrical equipment.

Therefore, the Code users should be cognizant that a sewage lift and treatment plant is not automatically considered to be Class I hazardous location, and that NFPA 820 provides important mitigating means under which this area could be deemed as an ordinary location. Classification of these areas should be done by qualified professionals.
 
And as usual – any contentious issues should be discussed with the local AHJ responsible for administration of the CE Code.
EIA Code Article - Nov 2014
By Ted Simmons 
Ted is the Chief Instructor, Electrical Apprenticeship Program - British Columbia Institute of Technology and is a member of the CSA Part 1 Code Committee.

In the previous article we reviewed the changes made to Sections 0, 2 & 4. This article will cover the changes made to Sections 6, 8, 10 & 12.
 
Section 6 – Services and service equipment
 
Rule 6-102 – Number of supply services permitted
 
In order to provide clarity, the wording “from the same system of any one supply authority” has been removed from Subrule (1).  The previous wording appeared to permit an installation to have two supply services of the same voltage provided they were supplied from different systems.
 
Rule 6-206 – Consumer’s service equipment location
 
A new Subrule (3) has been added which now permits the service disconnecting means to be placed on the outside of the building or on a pole.  This is indeed a major change to the CEC and should provide greater flexibility with regards to the location of the service disconnecting means for new and existing installations.
For example, it will now be possible to install a 4-gang meter mounting device and have the 4 service disconnecting means placed on the outside of the building or on a pole.  As noted in Subrule (3)(a) the service disconnecting means must be installed in an enclosure approved for the location such as a Type 3R or protected against the weather.
 
In addition, Subrule (3)(b) requires the service disconnecting means to be protected from mechanical damage if it is located less than 2m above ground.
 
Rule 6-300 – Installation of underground consumer’s service conductors
 
In order to provide a means for transitioning between conductors with different insulation temperature ratings, Item (b) has been added and now permits a splice to be made in single or multiple-conductor cable for service entrance use below ground.
 
Rule 6-302 – Installation of overhead consumer’s service conductors
 
Subrule (1)(f) has been revised to include copper-sheathed cable as an acceptable wiring method for an overhead consumer’s service.
 
Rule 6-310 – Use of joints in consumer’s service neutral conductors
 
Due to the adverse effects of open neutral connections, Rule 6-310 generally does not permit the use of splices in the neutral or identified conductor.  The Rule does, however provide exceptions to this requirement and now includes a new Subrule (3) permitting the neutral to be spliced where a cable transition is made to accommodate the requirements of Rule 4-006.
 
Section 8 – Circuit loading and demand factors
 
Rule 8-200 – Single dwellings
 
Due to the ever increasing cost of fuel, there has been a significant increase in the use of electric vehicles.  In fact, it is anticipated that 1 of every 20 vehicles on our roads will be electrically powered by the year 2020.  As a result of the rapid increase in the use of electric vehicles the CEC has introduced several new requirements.  For example, in order to ensure the ampacitiy of the service conductors for single dwellings is adequate for the vehicle charging equipment, a new Item (vi) has been added to Rule 8-200(1)(a) and requires any electric vehicle charging equipment loads to be added with a demand factor of 100%.
 
Figure 1 illustrates a typical single dwelling demand calculation which includes the load for an electric vehicle charger.
 
Figure 1

It should be noted that the requirement as to whether or not to install a receptacle for electric vehicle charging equipment is located in Rule 26-710(o).  This rule states that the receptacle is required only when mandated by the National Building Code of Canada.  Appendix “B” should be consulted for further information on this requirement.
 
Rule 8-202 – Apartment and similar buildings
 
Again, in order to ensure the service conductors are adequate for the electric vehicle charging loads, a new Item (d) was added to Rule 8-202(3).  The new Subrule requires any electric vehicle charging equipment loads not located in dwelling units to be added with a demand factor of 100%.  This new requirement could have a significant impact on the size of the main service equipment for apartments and similar buildings.
 
For example, if 20 of the car spaces in a 100 suite apartment complex are each equipped with a 6kW electric vehicle charger, the demand on the main service would be calculated at 20 suites x 6kW x 125% = 150kW.  The use of the 125% factor is a result of
Rule 86-302 which considers electric vehicle charging equipment loads to be continuous for the purposes of Rule 8-104.
 
Section 10 – Grounding and bonding
 
Rule 10-000  -  Scope
 
In order to provide clarity, the Scope of Section 10 has been revised significantly to clearly indicate that the Rules in this section cover the following requirements pertaining to:
 
1) bonding non-current carrying metal parts of electrical equipment and metal systems together with a connection to the grounded system conductor where present. 
 
2) grounding the electrical system and associated non-current carrying metal parts.
 
3) the use of ungrounded systems or systems incorporating neutral grounding devices.
 
Rule 10-002  - Object
 
In previous editions of the Code, the objectives of “grounding” and “bonding” were treated jointly, which in some cases led to confusion with interpretation and application of rules.  The 2012 CEC has been revised to provide a separate object for each of these terms as well as addressing the use of ungrounded systems or systems incorporating neutral grounding devices.
 
As noted, the object of bonding metal parts and metal systems together, and to the grounded system conductor, is basically to reduce the danger of electric shock or property damage by providing a low impedance path for fault current and to establish an equipotential plane to minimize the possibility of a potential difference between metal parts.
 
The object of grounding the electric system and non-current carrying metal parts is to connect the earth to the equipotential plane in order to minimize any potential difference to earth.  The new Code indicates the object of using an ungrounded system or a system incorporating a neutral grounding device is to limit the magnitude of fault current and minimize the damage resulting from a single fault.
 
Rule 10-106  -  Alternating current systems
 
In order to align editorially with the rest of the Code the term “ground detection” was revised to “ground fault detection”.
 
Rule 10-212  -  Grounding connections for equipment in an ungrounded system
 
The use of ungrounded systems or a system incorporating neutral grounding devices is not new, however the Code was silent on the grounding connections for these systems.
As a result, Rule 10-212 has been added to the Code and as noted in Subrule (1) requires there be no connection between the grounding conductor and the system neutral, where  one is present.  Subrule (2) requires the grounding conductor for the ungrounded system to connect the grounding electrode to the grounding terminal at the service box, or the equivalent where a service box is not installed.  A new note was added to Appendix “B” to provide further information on this requirement.
 
Rule 10-624  -  Bonding equipment to the grounded system conductor
 
Three new Subrules have been added to this Rule to identify the requirements pertaining to the bonding of equipment to the grounded system conductor. 
 
Subrule (1) indicates the connection between the metal enclosure of the service box, or equivalent equipment such as a transformer or generator, shall be made with a bonding screw or strap supplied with the equipment. 
 
As noted previously in Rule 10-002(1), one of the primary reasons for bonding metal parts together and connecting them to the grounded system conductor was to provide a low impedance path for the fault current back to the source.
 
In order to ensure field installed bonding jumpers are adequate for this purpose,
Subrule (2) was added and requires where a bonding screw or strap is not provided, a bonding jumper sized in accordance with Table 16 shall be used. 
 
For example, a 600A, 3-phase, 4-wire service is installed using a 600A main switch supplied with parallel runs of 350 kcmil, TW75 copper conductors.  The main switch is not equipped with a bonding screw or strap.  The size of copper bonding jumper required between the metal switch enclosure and the grounded conductor bus would be determined as follows:
 
Step 1) Use Table 2 to determine the ampacity of the service conductors.
            Table 2 → 350 kcmil → 75°C → 310A
                                       Parallel runs →     x 2
                                                                   620A
Step 2) Use Table 16 to determine the size of bonding conductor.
            Table 16 → Note: because the conductor ampacity exceeds 600A
                                          we must use 800A which requires a #1/0 copper
                                          bonding conductor.
 
The same process would be followed when determining the minimum size of bonding conductor required between a metal transformer enclosure and the grounded conductor bus or “X0” terminal.
 
For example, if a 75KVA dry-type transformer uses 300 kcmil, R90 XLPE conductors to supply a 225A, 120/208V, 3-phase, 4-wire panelboard, the bonding jumper would be determined as follows:
Step 1) Use Table 2 to determine the ampacity for the secondary conductors.
            Table 2 → 300 kcmil → 90°C → 320A
 
Step 2) Use Table 16 to determine the minimum size permitted for the bonding
            conductor.  As noted previously, because the conductor ampacity exceeds 300A
            we must use 400A, which requires a No.3 AWG copper bonding conductor.
 
A new Subrule 3 has been added to address situations where the enclosure of the service box or equivalent is not metal.  (For example, RPVC)  In these situations, the Code requires the bonding bus or terminal provided with the non-metallic enclosure to be interconnected with the grounded conductor bus in the same manner as the enclosure would be.  This would generally be accomplished by installing a bonding jumper sized in accordance with Table 16.
 
Rule 10-700  -  Grounding electrodes
 
As a result of the elimination of Table 17, Subrule 10-700(2)(a)(i) has been revised to indicate that when 2 rod electrodes are installed, they shall be bonded together with a grounding conductor sized in accordance with Rule 10-812 instead of Table 17.
 
This change removes a problem which existed in the previous Code where the grounding conductor from the rod electrode to the grounded conductor bus was permitted to be
No.6 AWG copper and the conductor between the two rod electrodes was required to be sized in accordance with Table 17, which in many cases resulted in a conductor size larger than No.6 AWG.
 
Rule 10-810  -  Grounding conductor size for DC circuits           
 
A new Subrule (2) has been added to address the requirements for determining the size of the grounding conductor for photovoltaic systems and renewable energy systems.  The Code now permits the grounding conductor for these systems to be sized in accordance with Rule 10-812.  As a result, a No.6 AWG copper conductor may be used.
 
Rule 10-812  -  Grounding conductor size for alternating current systems and for
                          service equipment
 
This is likely one of the most talked about changes to the Code.  Rule 10-812 has been revised to permit the size of the grounding conductor connected to a grounding electrode conforming to Rule 10-700 to be not smaller than No.6 AWG copper.  This change also led to the elimination of Table 17.
 
As explained in the Appendix “B” note for Rule 10-812, in a fault situation the majority of the fault current will follow the low impedance path provided by the grounded system conductor back to the source.  As a result, it has been determined that a grounding conductor sized not less than No.6 AWG is adequate to carry any portion of the fault current that will flow through it.
Rule 10-814  - Bonding conductor size
 
The wording “permitted to be” has been removed from Subrule (2) to remove any impression that a bonding conductor was not required to be paralleled.  In other words,
a bonding conductor is required in each parallel run
 
Section 12 – Wiring methods
 
Rule 12-012 – Underground installations
 
In order to harmonize with the CSA Standards for sand and gravel particulate sizing, Subrule (4) has been revised and now requires the screened sand used to bed direct buried conductors or cables to have a maximum particle size of 4.75 mm.  The previous Code permitted 6 mm.  A new note was added to Appendix “B” indicating the maximum
size of sand relates to the standard sieve sizes detailed in ASTM D2487.
 
Rule 12-102 – Insulated conductors
 
This rule identifies the requirements that pertain to the installation of insulated conductors when the ambient temperature is liable to become low enough to cause damage to the conductor insulation either during or after installation.
 
The rule originally applied to thermoplastic-insulated conductors only, however it has now been revised to include all insulation types.  A new note has been added in Appendix “B” to provide guidance on how to handle insulated conductors at low ambient temperatures.
 
Rule 12-108 – Conductors in parallel
 
Several changes have been made to this rule.  Subrule (1) has been revised to indicate that it applies to both ungrounded and grounded conductors.  In addition, the rule now refers to conductors that are paralleled together to form a single conductor as a set.
Subrule (1) also contains a new Item (e) which requires each parallel conductor set
to be comprised of conductors that are the same conductor material
 
A new Subrule 2 has been added to provide a means for complying with the equipment temperature ratings outlined in Rule 4-006.  As noted, Subrule (2) now permits a single splice for each conductor forming part of a parallel conductor set provided the splice is made to meet the requirements of Rule 4-006 and the conductors are spliced in the same manner.  In order to satisfy this requirement, approved devices of the same type would be required to splice each conductor of a parallel set.
 
Subrule (3) was added to indicate that in parallel sets, conductors of one phase, polarity or grounded circuit conductor need not have the same characteristics as those conductors of another phase, polarity or grounded circuit conductor. 
 
Rule 12-120 – Supporting of conductors
 
When armoured cables such as TECK90, AC90, ACWU90, etc. are installed in vertical runs, the weight of the internal cable assembly may cause excessive strain on conductor terminations.  In order to address this concern Subrule (4) has been added and requires
the internal assembly of cables such as TECK90, AC90, ACWU90, etc. to be supported at intervals not exceeding those specified in Table 21. 
 
Alternatively, as noted in items (a), (b) & (c) the internal cable assembly could also be supported by:
            - incorporating a bend or bends equivalent to a total of not less than 90° at
              intervals not exceeding the distances specified in Table 21.
 
            - installation of a horizontal run of the cable not less than the length of the
              vertical run.
 
            - use of cable that is specifically designed for vertical runs, such as Risertek 90
              cable, etc.
 
Rule 12-510 – Running of cables between boxes and fittings
 
In order to prevent damage to the outer covering on non-metallic sheathed cables, as well as the insulation on the conductors, Rule 12-510(3) and Rule 12-520 have been revised to prohibit fishing of non-metallic sheathed cables where metal sheeting or cladding, metal joists, metal top or bottom plates, or metal studs are used. 
 
Rule 12-600 – Armoured cable work Rules
 
Up until recently armoured cables were not permitted to be installed in raceways (other than situations where the raceway was being used to provide mechanical protection).
The 2012 CEC however, has been revised to permit the use of armoured cable in a raceway provided the installation complies with Rules 12-602(6), 12-614(3) and 12-902(2).
 
Rule 12-602 – Use
 
Subrule (6) was added to permit armoured cable for use in a raceway provided the armoured cable has an overall jacket and is installed in accordance with
Rule 12-902(2).
 
Rule 12-614 – Radii of bends in armoured cables
 
When armoured cables are pulled into a raceway, the armour and inner insulated conductors could be damaged as a result of the required increased pulling tension.  In order to address this concern Subrule (3) has been added to specify that where jacketed armoured cables are installed in raceways, the minimum bending radii measured at the innermost surface of the conduit or tubing shall not be less than:
           
            - 10.5 times the diameter for low-voltage cable
            - 18 times the diameter for high-voltage cable
            - those specified by the cable manufacturer
 
Rule 12-902 – Types of conductors and cables
 
The title and content of this rule have been revised to permit the use of jacketed armoured cables in raceways.  Subrule (2) specifies the requirements that must be satisfied as follows:
 
- Item (a) requires the installation not result in a greater conduit fill than that specified in Table 8.  For example, the minimum conduit size required for a 3-conductor jacketed TECK90 cable with copper conductors and a diameter of 50mm would be calculated as follows:
 
(Area = π r² = 3.1416 x 25² = 1963.5mm²)
Table 8 tells us that we can fill the conduit to 53%.
Table 9 indicates the minimum conduit size permitted would be 78mm or 3 in.
 
- Item (b) also requires that the installation complies with one of the following conditions:
 
            - Item (b)(i) requires that the length of cable pulled into the conduit does not         result in the calculated maximum pulling tension or the calculated maximum            sidewall bearing pressure being exceeded.  As noted in Appendix “B” this      information is available from cable manufacturers.
 
            - Alternatively, Item (b)(ii) requires the run of conduit between draw-in points       not have more than the equivalent of two 90° bends with a minimum bending          radius of not less than .944m for cable rated 1000V or less and 1.524m for cable       rated in excess of 1000V.
 
            - In addition, the length of conduit between draw-in points must not exceed:
                        -15 m for a three conductor copper cable
                        - 45 m for a single conductor copper cable
                        - 35 m for a three conductor aluminum cable
                        - 100 m for a single conductor aluminum cable
 
Using our previous example, if it was not possible to provide the information required by Item (b)(i) then the run of conduit between draw-in points could not have more than the equivalent of two 90° bends with a minimum bending radius of .944m and be restricted to a length of 15m.
 
A new note providing further information on these requirements has been added to Appendix “B”.
 
 Rule 12-1014 – Conductors in conduit
 
As a result of the introduction of RPV 90 and RPVU 90 cables for solar photovoltaic wiring, it was necessary to add Table 10B which provides the dimensions of PV cable for the purpose of calculating conduit and tubing fill.  Subrule (4)(d) has been revised to direct Code users to the new Table.
 
Rule 12-1308 – Supports
 
Up until now the Code has been silent regarding the support requirements for liquid-tight flexible conduit which in this regard has led to inconsistency and confusion.  In order to address this concern, Rule 12-1308 has been added to the Code and requires liquid-tight flexible conduit to be supported by straps or other devices within 300mm of every outlet box, junction box, or fitting and with spacing between supports of not more than 1.5m.
A new Subrule (2) which permits liquid-tight flexible conduit to be fished has also been included with Rule 12-1308.
 
Rule 12-2104 – Conductors in raceways
 
In order to provide clarity, Subrule (2) has been revised to indicate that each compartment of a divided wire-way may be treated separately when determining the maximum number of conductors and the interior cross-sectional area.
 
Rule 12-2200 – (Cable trays) Method of installation
 
In the previous Code, Subrule 12-2200(2) required that the maximum design and support spacing for cable trays not exceed the ratings specified by the manufacturer.  To assist installers with determining these requirements, Subrule (2) has been revised to require the maximum design load and associated support spacing not exceed the load/span ratings of the cable tray, which as noted in Appendix “B”, is required to be included with the marking on the cable tray.
 
Figure 1 is an example of the Part II product marking requirements for cable tray.
(Courtesy of Unitray Systems Inc.)



Cablebus – Rules 2250 to 2260
 
A new Subsection to address the installation requirements for cablebus has been added to Section 12.   Cablebus is defined in Section 0 as an assembly of insulated conductors with fittings and conductor terminations in a completely enclosed, ventilated, or non-ventilated protective metal housing.  The note for cablebus, located in Appendix “B”, indicates cablebus is normally assembled at the point of installation from the components furnished or specified by the manufacturer in accordance with the instructions for the specific installation.
 
Figure 2 illustrates a cross-sectional view of a cablebus assembly.
(Courtesy United Wire & Cable)

The new cablebus subsection contains 6 new rules which identify the requirements pertaining to:
  • use of cablebus
  • methods of installation
  • connection to other wiring methods
  • provisions for bonding
  • ampacities of conductors in cablebus
 Special attention should be given to the extensive information pertaining to cablebus systems that has been added to Appendix “B”.
 
Rule 12-3000 – Outlet boxes
 
Three new Subrules have been added to this Rule.  In order to eliminate potential shock hazards, Subrule (3) now requires that metallic fittings used to terminate non-metallic wiring methods to a non-metallic outlet box be bonded to ground.  This requirement is typically accomplished by installing a bonding bushing.
 
Subrule (8) was added to exempt switches and receptacles having an integral enclosure from the requirements of Subrule (1) which state a box or an equivalent device shall be installed at every point of outlet… 
Figure 3 provides an example of a receptacle with an integral enclosure.
(Courtesy Pass & Seymour a business unit of Legrand)


These devices are typically used where wall depth is an issue such as recreational vehicles, mobile homes, etc.
 
Subrule (9) has also been added and indicates where a pendant ceiling fan and all possible accessories weigh less than 16kg and are intended to be supported by a ceiling outlet box, the outlet box must be approved and marked for fan support.
 
Rule 12-3010 – Outlet box supports
 
This rule also contains 3 new Subrules.  Subrule 12-3010(7) was added to exempt switches and receptacles having an integral enclosure from the support requirements identified in Subrule (1).  Subrule 12-3010(8) requires where a ceiling outlet box marked for fan support is installed, the outlet box must be securely attached to the building structure or be attached by a bar hanger attached directly to the building structure.  Subrule 12-3010(9) requires fans and all possible accessories weighing 16kg or more to be supported independently of the outlet box.
 
Rule 12-3022 – Entrance of conductors into boxes, cabinets, and fittings
 
As noted in the revised Subrule (7) the previous requirements pertaining to single conductor cables or conductors entering metal boxes through separate openings have been relocated to Rule 4-010.
 
Rule 12-3032 – Wiring space in enclosures
 
Subrule (4) has been added to permit enclosures which house overcurrent devices, controllers and externally operated switches to be used as a raceway for wiring associated with instrument transformers and energy usage metering devices provided:
  • the enclosure is approved to house these devices
  • the wiring does not fill the wiring space at any cross-section to more than 75% of the cross-sectional area of the space
In the next article, we will review the revisions made to Sections 14, 16 and 18.
Check the EIA website for important updates, events, and news. 

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