Copy
EIABC - The Inspector Newsletter - 2016 February
View this email in your browser

Message from the President 

 
Hello fellow members. 

Last weekend’s code review was a huge success and I wanted to thank the membership on getting the word out to the electrical community. We had a large demand for the seminar and had to unfortunately turn some people away. At present we are looking on having one more additional seminar to include any that may have missed out on the event. Time and date will be announced once we confirm numbers.

I would also like to send out a big thank you to our existing board members for all the time and effort they spent on association business and for the code review seminar this past year. This has not been a typical year and their efforts this past year has not gone unnoticed.
 
Our next dinner meeting is fast approaching and will be held at the Burnaby Mountain Golf Course on February 22nd. This will be an important meeting due to election of the board for the 2016 year. Please sign up early and let me know if you may be interested in becoming a board member for this upcoming year.
 
Please check out our website for all of our scheduled dinner meetings for this year. Complete schedule is under the Events tab / Event Calendar on the website.
 
Our strength is in our membership. Please do not hesitate to send all your suggestions and ideas to myself on how we, as your executive board, can better support the membership. I can be reached at president@eiabc.org.
 
Thanks and see you in February.

Thanks,
Jason Rowley
President  EIABC
president@eiabc.org
AGM Dinner tickets are available on our website.
Buy Ticket

February 2016


Inside This Issue


Message from the President
- Jason Rowley

Outdoor Installation of Dielectric liquid-Filled Equipment...Are Requirements Clear to Code Users?
- Ark Tsisserev

EIA Code Article - February 2016
- Ted Simmons

 


EIA Executive
 

Electrical Inspectors Association of British Columbia

Suite 201, 3989
Henning Drive Burnaby,
B.C., V5C 6N5

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

Buy or Renew Your Membership Online
Membership

Outdoor Installation Of Dielectric Liquid-Filled
Equipment... Are Requirements Clear To Code Users?

 
By Ark Tsisserev, P.Eng.
Ark Tsisserev is an independent electrical fire and safety 
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

When dielectric liquid-filled electrical equipment is intended to be installed indoors, requirements of Rule 26-012 of the CE Code would have to be met (i.e. this equipment would have to be located in an electrical equipment vault or in a service room, and construction of such a vault or a service room would have to conform with the applicable provisions of the National Building Code of Canada). 

But what about installation of dielectric liquid-filled equipment outdoors? Does such equipment have be located in fire rated rooms and vaults? The answer can be found in Rules 26-014, 26-242 and 26-244 of the CE Code. 

While Rules 26-242 and 26-244 apply only to installation of dielectric liquid-filled transformers, Rule 26-014 covers generic safety requirements for such installation of all types of dielectric liquid-filled electrical equipment as follows:
 
“26-014 Dielectric liquid-filled equipment – Outdoors (see Appendix B) 
  1. Except as permitted by Subrule (3), dielectric liquid-filled electrical equipment containing more than 46 L in one tank, or 137 L in a group of tanks, and installed outdoors shall not be located within 6 m of 
    (a) any combustible surfaces or material on a building; 
    (b) any door or window; or 
    (c) any ventilation inlet or outlet. 
  2. The dimension referred to in Subrule (1) shall be the shortest line-of-sight distance from the face of the container containing the liquid to the building or part of the building in question. 
  3. Notwithstanding the requirements of Subrule (1), the equipment shall be permitted to be installed within 6 m of any item listed in Subrule (1)(a), (b), and (c), provided that a wall or barrier with non-combustible surfaces or material is constructed between the equipment and that item.
  4. Where dielectric liquid-filled electrical equipment containing more than 46 L in one tank, or 137 L in a group of tanks, is installed outdoors it shall 
    (a) be inaccessible to unauthorized persons; 
    (b) not obstruct firefighting operations; 
    (c) if installed at ground level, be located on a concrete pad draining away from structures or be in a curbed area filled with coarse crushed stone; and 
    (d) not have open drains for the disposal of the liquid in proximity to combustible construction or materials
The safety objective of Rule 26-014 of the CE Code is to prevent burning insulating liquid (which could burn under certain fault conditions) from reaching doors, windows or other openings on a building or from reaching combustible surfaces of a building – 6 m clearance mandated by this Rule is deemed to be sufficient to prevent a potential fire hazard from burning insulating liquid. This Rule allows reducing the required clearance under a very specific condition (i.e. provided that a wall or a barrier with a non-combustible surface is constructed between the piece of equipment and the building). 

The objective of this Rule is also to prevent access to the live parts of the dielectric liquid-filled equipment to unauthorized persons. Although the safety provisions of the CE Code in general (and of Rule 26-014 – in particular) apply only when electrical equipment is being installed in conformance with the CE Code, some jurisdictions are using the safety objective of Rule 26-014 in respect to the clearances from already existing dielectric liquid-filled equipment, when electrical work takes place on newly constructed buildings or on the existing buildings subjected to renovations or additions projects. 

For example, City of Vancouver Electrical Inspections Branch has published the explanatory Bulletin on application of Rule 26-014 of the CE Code – by clarifying that every newly constructed building or every existing building that is subjected to electrical work associated with additions and alterations, has to be evaluated for compliance with the clearances required by Rule 26-014. This Bulletin was issued in light of the fact that BC Hydro traditionally provided overhead services to its Vancouver customers, and as a result, there have been too many existing high voltage installations of pole mounted dielectric liquid-filled transformers throughout the City of Vancouver that are in conflict with clearance requirements of the current CE Code. Thus, installations where a close proximity of such pole mounted dielectric liquid-filled equipment present obvious safety hazards. 

As BC Hydro pole-mounted dielectric liquid-filled transformers already exist on streets and alleys, this clarification Bulletin was intended to advise electrical designers and electrical installers that evaluation must be carried out to ensure that a potential explosion of the existing BC Hydro transformers will not adversely affect newly constructed or renovated buildings. Provision of item 26-014(4)(a) of the CE Code “be inaccessible to unauthorized persons” has been also extended by this Bulletin to high voltage overhead conductors used in conjunction with pole mounted dielectric liquid-filled transformers, as Table 33 of the CE Code mandates minimum 3 m horizontal clearance of the high voltage conductors from the adjacent buildings and structures. 

Some jurisdictions publish specific directives or bulletins – to also clarify conditions for application of item 26-014(4)(b) which mandates that the dielectric liquid-filled equipment installed outdoors must “not obstruct firefighting operations”. Therefore, in addition to the generic provisions of Rule 26- 014, existence of all applicable regulatory bulletins or directives should be checked in conjunction with application of Rule 26-014 of the CE Code. 

Let’s now review particular requirements of the CE Code for outdoor installation of dielectric liquid-filled transformers. Rule 26-242 deals with this particular subject as follows: 

“26-242 Outdoor transformer installations 
  1. Except as permitted by Subrule (2), where transformers, including their conductors and control and protective equipment, are installed outdoors, they shall 
    (a) be installed in accordance with Rule 26-014 if they are dielectric liquid-filled; 
    (b) have the bottom of their platform not less than 3.6 m above ground if they are isolated by elevation; 
    (c) have the entire installation surrounded by a suitable fence in accordance with Rules 26-300 to 26-324 if they are not isolated by elevation or not housed in suitable enclosures; and 
    (d) have conspicuously posted, suitable warning signs indicating the highest voltage employed except where there is no exposed live part.
  2. Dielectric liquid-filled pad-mounted distribution transformers shall be installed at least 3 m from any combustible surface or material on a building and at least 6 m from any window, door, or ventilation inlet or outlet on a building, except where
    (a) a wall or barrier with non-combustible surfaces or material is constructed between the transformer and any door, window, ventilation opening, or combustible surface; or 
    (b) the transformer is protected by an internal current-limiting fuse and equipped with a pressure relief device, with working spaces around the transformer of at least 3 m on the access side and on all other sides: 
    (i) 1 m for three-phase transformers; and 
    (ii) 0.6 m for single-phase transformers.” 
It could be seen from this Rule that it mandates compliance of installation of dielectric liquid-filled transformers with generic requirements of Rule 26-014, and that it also specifically states that each such dielectric liquid-filled transformer  must be surrounded “by a suitable fence in accordance with  Rules 26-300 to 26-324” – if the transformer is “not isolated  by elevation or not housed in suitable enclosures”. The wording “not housed in suitable enclosures” as a condition for a  fence around such transformer is selected not by accident.  

It should be noted that a typical pad mounted dielectric liquid-  filled transformer is not made “approved” by means of certification to the CSA certification standard (CSA Part II  standard), as there are no such Part II standards. Therefore, the provision of the installation Code could not rely on the  standard in order to state that the enclosure intended to prevent unauthorized access to the live parts of the equipment  must be specifically marked in accordance with the standard  – to indicate such fact to the users of the transformer.

These types of dielectric liquid-filled transformers are traditionally  used by utilities, and these transformers are  designed, constructed and tested to the CSA engineering  standard C227.4. Scope of this engineering (and not certification)  standard clearly states that when a transformer constructed  in accordance with the standard is, in fact, intended  for installation under provisions of the CE Code, then the  local inspection authorities should be consulted for acceptance  of such equipment. This means that the
  1. transformer would have to be made “approved” by a  means of field evaluation to the CSA Model Code SPE  1000, and
  2.  field evaluation must be performed by a “Special Inspection”  body accredited by the Standards Council of  Canada, and
  3. “approval” would have to be subjected to the acceptance  by the AHJ which inspects the installation.
Thus, if the SI body which performs a field evaluation of  such transformer could state that the transformer is housed in  a “suitable enclosure” for the purpose of prevention of unauthorized  access, then construction of a fence around such  dielectric liquid-filled transformer would not be warranted in  accordance with paragraph 26-242(10(c) of the CE Code.

It should be also noted that in majority of cases, a complete integrated assembly comprising a HV load break, metering equipment, dielectric liquid-filled transformer and  a LV switchboard is brought for installation on a concrete pad (see photos).
Such integrated assembly is called “unit substation”, and  this unit substation would have to be made “approved” before  the AHJ could allow it to be installed under provisions of the  CE Code. This “approval” would have to be also performed  by means of a special inspection to the CSA Model Code SPE  1000, as there are no other means available to make such  integrated assemblies “approved”.  

A proposal has been recently submitted to the CSA – to  amend Rule 26-242 so, as to reflect this practical issue.

Let’s now take a look at Rule 26-244, which regulates  installation of dielectric liquid-filled transformers on roofs of  buildings:

“26-244 Transformers mounted on roofs (see Appendix B)  
  1. Except as permitted by Subrule (2), dielectric liquid-filled  transformers installed on the roof of a building shall be  located in an electrical equipment vault in accordance with  Rules 26-350 to 26-356, and adequately supported by means of non-combustible construction.  
  2. Transformers containing a non-propagating liquid, suitable  for the purpose and having a flash point not less than  275°C, that are installed on the roof of a building need not  be located in an electrical equipment vault but shall not be  placed adjacent to doors or windows, nor within 4.5 m of  discharge vents for flammable fumes or combustible or  electrically conductive dusts”.
It could be seen from this Rule that the dielectric liquidfilled  transformers intended to be located on the roof of a building, must be installed in an electrical equipment vault, unless conditions specified in Subrule (2) are met.  

However, as usual – in each specific installation case, the  AHJ with jurisdictional authority for administration of the CE Code should be consulted.
EIA Code Article - February 2016
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. Ted_Simmons@bcit.ca


The 23rd edition of the CE Code Part I was introduced to the electrical industry across Canada in January 2015. The new Code has been extensively updated and contains over 200 revisions.  The changes which are a result of a consensus based process will improve electrical safety, enable Code users to keep pace with emerging technologies, and will provide positive benefits to the entire industry.
 
It is important to recognize that despite the fact that the 2015 CE Code has been published and is available for purchase, the 2012 CE Code will remain in effect until the new Code is adopted by the respective authority having jurisdiction.
 
In the previous article, we provided a detailed review of the changes made to Sections 0 and 2.  In this article we will analyze the revisions made to Section 4.

Rule 4-004 – Ampacity of wires and cables
 
Subrule 4-004(1)(d) and (2)(d)
 
In the previous Code, the diagrams pertaining to the installation configurations for underground cables and raceways were located in Appendix B, with the corresponding conductor ampacity tables located in Appendix D.  At times this was cumbersome and as a result, the installation configuration diagrams for underground cable and raceways have been relocated adjacent to their appropriate ampacity Tables in Appendix D.  An example of this revised arrangement is illustrated in Figure 1.  As noted, Subrules (1)(d) and (2)(d) have been revised to reflect this change.

Figure 1  -  Diagram D8 & Table D8A

 

In addition to the inclusion of the installation configurations with the underground ampacity Tables located in Appendix D, the previous maximum continuous load requirements have also been removed.  This change appears to have increased the ampacities for underground installations, however, it must be noted that the requirements for maximum circuit loading outlined in Rule 8-104 still apply. 
 
The removal of the continuous loading requirements also resulted in a reduction in the number of Tables.  ie: the removal of Tables D12A to D15B.

Subrule 4-004(1)(g) and (2)(g)
 
Up until now, the Code has not provided a specific method for determining conductor ampacities for high voltage cables.  In order to address this issue, Subrules 4-004(1)
and (2) have both been revised to include a new Item (g).  Item (g) indicates that for shielded cables rated 5kV to 46kV in sizes No. 2 AWG to 1000 kcmil, installed in accordance with the configurations specified in Diagrams 17A to 17N, and the conditions of use outlined in Table D17, the conductor ampacity shall be obtained from Tables D17A to D17N or as calculated by the IEEE 835 calculation method.
 
For example, a No. 2 copper, full neutral, 15kV cable installed in accordance with the configuration shown in Diagram 17A and the conditions of use outlined in Table D17 would have an ampacity of 221 amps.  A new note providing further information on Subrules 4-004(1)(g) and (2)(g) has been added to Appendix B.
 
The introduction of the requirements for determining high voltage conductor ampacities has also resulted in the titles of Tables 1 to 4 being restricted in their use to unshielded conductors rated not more than 5000V.

Subrule 4-004(10)
 
Several questions have been raised regarding the correct application of this Subrule.  In the 2012 CE Code this subrule indicated that for up to and including four single conductor cables in free air spaced at less than 25% of the diameter of the largest cable, the ampacity was to be in accordance with Subrules (1)(b) and (2)(b) multiplied by the correction factor obtained from Table 5B.  This appeared to be a fairly straightforward calculation, however, being that Subrules (1)(b) and (2)(b) refer to Tables 2 and 4 respectively, questions were raised as to why the Code directed users to apply the correction factors from Table 5B which, as noted in the table heading, apply specifically to Tables 1 and 3.
 
In order to address this issue, Subrule 10 has been revised to reference Subrules (1)(a) and (2)(a) instead of Subrules (1)(b) and (2)(b).
 
Subrule 4-004(12)
 
In order to provide additional clarity, the wording “based on the total number of conductors” was added at the end of the Subrule.
 
Subrule 4-004(13)
 
This Subrule has been revised to correct a previous editorial error and now indicates where the length of a single-conductor cable run spaced at less than 25% of the largest cable diameter is less than 600mm, the correction factor from Table 5C shall not apply.
 
Subrule 4-004(14)
 
This longstanding Subrule which was omitted from the 2012 CE Code has been reinstated in the 2015 CE Code.  It has been revised to clarify that the correction factors obtained from Tables 5C shall be based on the total number of conductors in the cables.
 
For example, six 3c#10 cables are installed to supply six 3Ø squirrel cage induction motors.  If the cables are run in contact with each other for 900mm, Table 5C would require an ampacity correction factor based on 18 conductors which is 0.70.
 
Subrule 4-004(23)
 
This is a new Subrule which now permits service conductors for single dwellings, and feeder conductors supplying single units of row housing of apartments and similar buildings, to be sized in accordance with a new Table 39, provided the calculated load does not exceed the values specified therein.
 
For example, according to Table 39, 2/0 AWG copper 75°C conductors may be used for a 200A single dwelling unit service provided the calculated load does not exceed 184A.
Particular attention should be given to Note 3 in Table 39 which states if the calculated load exceeds the limit shown in the Table, the next larger size conductor shall be used.
The new Table 39 is illustrated in Figure 2.


It should be noted that both Subrule (23) and Table 39 require that the conductors terminate on equipment having a conductor termination temperature of not less than 75°C.  Table 39 also states that the 5% allowance outlined in Rule 8-106(1) cannot be applied to the values in the Table.
 
Rule 4-006 – Temperature limitations
 
This rule has undergone major revision.  However, the intent of the Rule which is to ensure that the ampacity of conductors be selected from the temperature column in Tables 1, 2, 3, or 4 that corresponds to the temperature rating marked on the electrical equipment, has not changed.  The revisions to this Rule include the following:
 
Subrule 4-006(2)(a) indicates where the maximum conductor termination temperature for equipment is not marked, the maximum conductor termination temperature shall be considered to be 60°C for low voltage equipment rated 100A or less, or marked for use with conductors smaller than No.1 AWG.  For equipment rated 100A or more, or marked for use with conductors larger than No.1 AWG, Subrule (2)(b) indicates the maximum conductor termination temperature shall be considered to be 75°C.
 
Subrule 4-006(3) permits the manufacturer to be consulted to establish the permitted termination temperature where the maximum conductor termination temperature is not marked on high-voltage equipment.
 
Subrule 4-006(4) indicates that the temperature limitation requirements outlined in Subrules (1) and (2) apply only to the first 1.2m of conductor length measured from the point of termination.
 
Subrule 4-006(5) indicates where a cable transition is made to satisfy the requirements outlined in Subrules (1) and (2), the length of a conductor terminating on equipment shall not be less than 1.2m.
 
In the next article, we will review the changes made to Sections 6, 8, and 10.
Check the EIA website for important updates, events, and news. 
Visit EIABC Website
Copyright © 2016 Electrical Inspectors Association, All rights reserved.


unsubscribe from this list    update subscription preferences 

Email Marketing Powered by Mailchimp