Christmas Dinner Meeting

Essential electrical systems and life safety systems
– is there a difference between them?

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

Tn the previous article we reviewed the changes made to Sections 6, 8, 10 and 12.
This article will review the changes made to the 2012 CEC for Sections 14, 16, 18,
20, 24 and 26.
 
Section 14 – Protection and Control
 
Rule 14-104 – Rating of overcurrent devices
 
During our review of the changes to Section 4 in a previous article, we indicated there were concerns regarding the increased ampacities permitted for No.14, No.12 and No.10 copper conductors, as well as No.12 and No.10 aluminum conductors.  In order to address the concerns a new Subrule (2) was added to Rule 14-104 to restrict the overcurrent protection for these conductors as follows:
 
(a)  15A for No.14 AWG copper conductors
(b)  20A for No.12 AWG copper conductors
(c)  30A for No.10 AWG copper conductors
(d)  15A for No.12 AWG aluminum conductors
(e)  25A for No.10 AWG aluminum conductors
 
The new requirements essentially maintain the ampacities for these conductors at their previous 2009 values.  Notes have been added to Tables 1, 2, 3 and 4 to remind Code users to consult Rule 14-104(2) regarding the overcurrent protection requirements for these conductors.  It should be noted that Item (e) does not appear in the text of the Code, however it is part of the CSA errata and as such must be added to the Rule.
 
Rule 14-510 – Use and rating of manually operated general-use ac switches
 
Subrule (1) has been revised editorially to clearly indicate the ampere rating requirements for general-use ac switches.  Subrule (2) was added and now requires that general use ac switches be specifically approved for the purpose and so marked.  The following information has been added to Appendix “B” to clarify the marking requirements:

                           Marking                                                       Indication
 

• elevated from a service or repair area by at least 50mm, or
• separated from a service or repair area by tight-fitting barriers such as curbs, ramps, or partitions at least 50mm high.

 
 Rule 20-110 – Equipment above hazardous areas
 
In the past, Rule 20-110(2) required permanently installed luminaires which were located over lanes through which vehicles are commonly driven or otherwise exposed to mechanical damage to be located at least 3.6m above the floor level.  If this was not possible, the Code required the luminaires to be of the totally enclosed type or be constructed to prevent the escape of sparks or hot metal parts.  Rule 20-110(2) has been revised to relax this requirement and now permits the use of luminaires suitable for non-hazardous locations provided they are protected from mechanical injury by a guard or by location.
 
Section 24 – Patient care areas
 
Rule 24-102 – Circuits in basic care areas
 
Interruption of circuits supplying essential electrical systems could jeopardize the effective and safe care of patients.  As a result, Subrule (6) has been added to
Rule 24-102 and requires that branch circuits supplying receptacles or permanently connected equipment deemed to be part of the essential electrical system not be used to supply receptacles or permanently connected equipment that are not part of the essential system.
 
Rule 24-104 – Bonding to ground in basic care areas
 
In order to minimize the possibility of potential differences between exposed conductive parts in the vicinity of the patient, Subrule (8) has been added and now requires that exposed non-current carrying metal parts of non-electrical equipment located within a patient care area be bonded to ground in accordance with Subrules (3) and (6).
 
A new note has been added to Appendix “B” to clarify which exposed metal parts of non-electrical equipment are required to be bonded to ground.  As noted, metal parts of medical gas equipment and metal parts of support arms or consoles installed in a patient care area should be bonded to ground.  However, metal parts of portable non-electrical equipment or metal parts of the building such as metal door or window frames need not be bonded to ground.
 
Rule 24-106 – Receptacles in basic care areas
 
Subrule (6) has been revised editorially to clarify that all receptacles supplied from circuits in an essential electrical system shall be coloured red.
 
Rule 24-306 – Emergency supply
 
The installation and performance requirements for emergency generators are located in CSA Standard C282.  As a result, the former Subrule (2) which required the prime mover of the generating set to be capable of operating independently of supplies, of water, and fuel from public utilities has been removed.
 
Section 26 – Installation of electrical equipment
 
Rules 26-360 to 26-368
 
The rules for motion picture studios, projection rooms and areas where cellulose nitrate films are stored were previously located in Section 48.  Several of these rules were considered no longer relevant and as a result, Section 48 was deleted from the Code. 
It was decided, however that some of the requirements be maintained for areas where cellulose nitrate films are stored for archive purposes which resulted in these specific rules being relocated to the new Subsection in Section 26 for cellulose nitrate film storage.
 
Rule 26-700 – General
 
To further enhance electrical safety for children, a new Subrule (12) has been added to Rule 26-700 to require all 5-15R and 5-20R receptacles installed in child care facilities to be of the tamper resistant type and so marked.  A new note has been added to Appendix “B” to clarify that unless otherwise designated by an authority having jurisdiction for child care facilities, a child care facility is considered to be an area designed to provide care to persons 7 years of age or less.
 
Rule 26-702 – Receptacles exposed to the weather
 
Subrule (1) has been revised to require the use of “wet location” cover plates for receptacles exposed to the weather.  A new Subrule (2) has also been added and requires receptacles of configurations of 5-15R, 5-20R, 5-20RA, 6-15R, 6-20R and 6-20RA to be provided with cover plates suitable for wet locations whether or not a plug is inserted in the receptacle.  These cover plates are sometimes referred to as “In-use covers”.  A note has been added to Appendix “B” to clarify the use and marking requirements for the two types of wet location cover plates.  As noted, the cover plates required for the specific receptacle configurations specified in Rule 26-702(2) are designed to be suitable for use in wet locations whether or not a plug is inserted into the receptacle.  These cover plates are required to be marked “Wet Locations”. 
 
The other wet location cover plates which are suitable for use in wet locations only when the plug is removed are required to be marked “Wet Location Only When Cover Closed”.
 
Figure 1 illustrates a 5-15R receptacle with a “Wet Location” or “In-use Cover Plate”

Figure 1
 
Rule 26-704 – Receptacles for maintenance of equipment located on rooftops
 
As noted previously Rule 2-314 was added to the Code and requires that where HVAC and similar equipment is installed on a rooftop (other than a dwelling unit) at least one receptacle shall be provided for the maintenance of the equipment.  Rule 26-704 has been
added to identify the installation requirements and requires the receptacle or receptacles to be:
 

• protected by a GFCI of the class A type
• supplied by a separate branch circuit that does not supply any other outlets or equipment
• of CSA configuration 5-20R
• located within 7.5m of the rooftop electrical equipment
• located not less than 750mm above the finished roof

• supplied from a grounded system
• permanently connected to a branch circuit that supplies no other equipment
• protected by a GFCI of the class A type