pdf Conference 2012 Submissions Draft

2012 Annual Technical Conference

Agenda item # 2012ag-0000                                  

FIRE CODE VARIANCE – INTERCONNECTION OF SMOKE ALARMS IN EXISTING SECONDARY SUITES

Question/enquiry:  

Are you aware of this relaxation? (for existing secondary suites only)

Recommendation: For information only

 Background information: 

• The AFC removes the requirement for wired interconnect but all units must still have a 120V supply.
• 120v wireless interconnected smoke alarms do not appear to be available yet in the Canadian market (listed to CAN/ULC-S531)
• Below is an example of this type of alarm on the US market

 How can First Alert® OneLink® alarms be relevant for Electrical Contractors who have existing home additions projects?

When dealing with new construction for existing home additions, the First Alert® OneLink® “Bridge” unit (SA520B) is a perfect solution. It is often difficult to connect to the existing alarm circuit when dealing with home additions. Concrete, steel, laminated beams, etc. are blocking easy access. The SA520B can be used in the new addition, where power can be obtained locally from a lighting or outlet circuit. In the existing part of the home, just replace one of the existing hardwired units with the SA520B. Link the two alarms to “bridge” the old and the new sections. Now all alarms will be interconnected, including other existing hardwired alarms that were interconnected in the old section.

First Alert® OneLink® smoke alarms will interconnect with most competitive smoke alarms, so retrofitting will not require replacement of existing competitive alarms. (Note: this is not true for competitive carbon monoxide alarms). In the new section, additional 9120B’s or 7010B's can be used and in the old section, other First Alert® OneLink® battery operated alarms can be used to bring the bedrooms, hallways, etc. up to code. First Alert® OneLink® alarms are a cost effective solution to renovation and remodeling.

 

 

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                               12-608 Continuity of armoured Cable                   

                                                                                                                      

Submitted by: Alberta Major Municipalities Meeting

Question/enquiry:   Is zero the allowable distance allowed to run just the interior jacketed cable of a Teck90 cable once the armour has been removed, even if the armour is properly terminated and bonded? 

Revised rule 12-608 cleared up the requirement to have the armour mechanically and electrically continuous for the entire run. Many installers still want to remove the armour and continue the inner jacketed cable at location changes. Examples:

• Detached residential garage feeds  - strip the armour at an outside junction box and continue the inner cable inside the building’s wall-space to a panel
• At a transition in an (ordinary location) industrial location from outside to inside , strip the armour at a coupling attached to a nipple and run the inner jacketed cable as a tray cable.

 

Recommendation:    For discussion.

 Background information: 

12-608 Continuity of armoured cable

Armoured cable shall be run in a manner such that the mechanical and electrical continuity of the armour is maintained throughout the run, and the armour of cables shall be mechanically and electrically secured to all equipment to which it is attached.

Armoured cables consist of single strips of interlocking steel or aluminum and provide good mechanical strength and flexibility. For mechanical and electrical continuity, Rule 12-608 requires that the cable be handled with care so as not to open the armour convolutions and be securely fastened to electrical equipment. Electrical continuity is important for bonding of the armour to ground. Mechanical continuity is obtained when the cable is securely supported on runs between and to equipment, in accordance with Rule 12-510. For a good mechanical and electrical connection, the armour of the cable must be gripped securely by the box connector or cable clamp.

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                           6-206 Length of service conductors in buildings                     

Submitted by: Alberta Major Municipalities Meeting

Question/enquiry:   When running service conductors over 3 m but less than 7.5 m, is it permissible to run part of the run in Rigid PVC and other parts in Rigid Steel or does the entire run need to be in rigid steel?

Recommendation: For discussion.

 Background information: 

CE Code 6-206 Consumer's service equipment location (see Appendices B and G)

(1) Service boxes or other consumer's service equipment shall be (e) as close as practicable to the point where the consumer's service conductors enter the building.

 

 

 

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                                   10-806 Installation of system grounding conductors                  

Submitted by:

Question/enquiry:

In Southern Alberta, it is a common practice to install a bonding bridge outside of the panelboard. The system grounding conductor is typically threaded through this bonding bridge and runs continuously to the neutral bar of the panelboard. Electricians then use this bonding bridge to bond the gas line and to terminate the primary protector grounding conductor for the communication system.

• If a system grounding conductor is too short, is it permissible to terminate it on a bonding bridge outside the panel and run a second piece of grounding conductor to the neutral bar in the panelboard?
• In a Solar PV system that will share the ac system grounding electrode, can the solar PV dc system grounding conductor terminate on this bonding bridge rather than at the neutral bar?

 

Recommendation: For discussion.

Background information: 

CE Code 10-806 Installation of system grounding conductors

(1) The grounding conductor for a system shall be without joint or splice throughout its length, except in the case of busbars, thermit-welded joints, compression connectors applied with a compression tool compatible with the particular connector, or where it is necessary to control the effects of stray earth current, devices specifically approved for connection in series with the grounding conductor.

Would you consider an exterior bonding bridge as a "busbar" 

 

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                                                                18-070 combustible gas detection                  

                                                                                                                      

Submitted by: Dan Green

Question/enquiry:  

Is the use of TEFC motors in Class 1 Zone 2 areas an acceptable practice? It seems some SCO’s are calling this as unacceptable.

Recommendation:  For discussion.

 Background information: 

Some have suggested rule 18-070 could be used to support the use of TEFC motors & equipment in Zone 2 locations. Some feel this rule alone can be used to de-rate a building. Under this rule, general purpose equipment can be used in a Zone 2 area IF (And here is the controversy) no other equipment is available (controversial on what this means) and failure will activate alarms, fans and shuts down equipment when LEL is reached. At first this rule was intended for Class I Div 1 Gas compressor ignition systems, as there is no Class I  Div 1 ignition systems available. Since then, most all gas compressors are Class I Zone 2 based on fugitive emissions studies. It is industry standard to have Gas detection in the building to shut down the equipment on high LEL gas.   18-070 Combustible gas detection

Electrical equipment suitable for non-hazardous locations shall be permitted to be installed in a Class I, Zone 2 hazardous location and electrical equipment suitable for Class I, Zone 2 hazardous locations shall be permitted to be installed in a Class I, Zone 1 hazardous location, provided that (a) no specific equipment suitable for the purpose is available; (b) the equipment, during its normal operation, does not produce arcs, sparks, or hot surfaces, capable of igniting an explosive gas atmosphere; and (c) the location is continuously monitored by a combustible gas detection system that will (i) activate an alarm when the gas concentration reaches 20% of the lower explosive limit; (ii) activate ventilating equipment or other means designed to prevent the concentration of gas from reaching the lower explosive limit when the gas concentration reaches 20% of the lower explosive limit, where such ventilating equipment or other means is provided; (iii) automatically de-energize the electrical equipment being protected when the gas concentration reaches 40% of the lower explosive limit, where the ventilating equipment or other means referred to in Item (ii) is provided; (iv) automatically de-energize the electrical equipment being protected when the gas concentration reaches 20% of the lower explosive limit, where the ventilating equipment or other means referred to in Item (ii) cannot be provided; and (v) automatically de-energize the electrical equipment being protected upon failure of the gas detection instrument.

Normal operation is the condition in which the installation and equipment operate within their design parameters. Combustible gas detection instruments are not only approved for their safety in hazardous locations, but also tested for performance in conditions outside of normal operation because of the importance of their readings to the user. CSA C22.2 No. 152 requires that these devices perform under many adverse conditions (e.g., extreme temperatures, humidity, and air velocity; high gas concentrations; and power fluctuations) without errors. They are also subjected to tests involving sudden changes in gas concentration and to long-term stability tests under simulated field conditions. As a result of this extensive testing and the favourable results obtained, these instruments are now considered a form of protection.    Rule 18-070 permits the installation of electrical equipment approved for Class I, Zone 2 hazardous locations in Class I, Zone 1 hazardous locations and permits the installation of equipment for non-hazardous locations in Class I, Zone 2 locations, provided that it complies with all of the conditions it lists.    Appendix H should be consulted for application, installation, and maintenance recommendations.

Apx B  Rule 18-070

It is intended that this Rule be used only where suitable equipment, certified for use in the hazardous location, is not available. For example, Class I, Division 1 ignition systems for internal combustion engines are not available; only Class I, Division 2 ignition systems are available. Therefore, ignition systems rated for Class I, Division 2 are currently the only hazardous location ignition systems available and could possibly be used in Class I, Zone 1 locations.    In many situations, proper area classification will eliminate the need to use this Rule. Rule 18-070 should not be used to compensate for improper area classification.    When this Rule is used, the gas detection system should consist of an adequate number of sensors to ensure the sensing of flammable gases or vapours in all areas where they may accumulate.    Electrical equipment that is suitable for non-hazardous locations and that has unprotected arcing, sparking, or heat-producing components must not be installed in a Zone 2 location. Arcing, sparking, or heat-producing components may be protected by encapsulating, hermetically sealing, or sealing by other means such as restricted breathing.    Before applying this Rule, the user should fully understand the risks associated with such an installation. When applying this Rule, it remains the responsibility of the owner of the facility, or agents of the owner, to ensure that the resulting installation is safe. Simply complying with the requirements of this Rule may not ensure a safe installation in all situations.

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                                                14-606 Panelboard Overcurrent Protection                  

                                                                                                                           

Question/enquiry:   Does this small 2 circuit panelboard meet the requirements of 14-606 when used in a service entrance application?

Recommendation: for discussion

 Background information: 

CE Code 14-606 Panelboard overcurrent protection

(1) Except for panelboards where more than 90% of the overcurrent devices supply feeders or motor branch circuits, every panelboard shall be protected on the supply side by overcurrent devices having a rating not greater than that of the panelboard.

These small panelboards are often used in small service applications such as telecommunications booster pedestals and  irrigation services.

• There is no main breaker.
• Service conductors terminate on the main bus bar lug. Load circuits are fed off the 2 pole breaker (typically a receptacle in an irrigation service)
• Neutral terminates on a neutral bus c/w removable brass tub bonding screw
• It is marked with: ’This Square D Sub Panel is suitable for use as service entrance equipment when used with a 2 pole breaker.”  (note a 2 pole breaker will take up all available spaces)

   QO2L70S

Square D   70 Amp QO Sub panel load center with 2 spaces, 4 circuits maximum

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                 14-106 Location and Grouping (of protective devices)                  

                                                                                                                            

Submitted by: City of Calgary

Question/enquiry:  

In multiple occupancies it is possible that a tenant does not have access to their overcurrent devices. An electrical panel can be located in a basement suite being used for rental and the other tenants cannot get at their breakers unless access is arranged through the owner. This could lead to unsafe situation if the power had to be turned off in a hurry.

Recommendation:

Rule 14-106 states that overcurrent devices shall be located in a readily accessible location. 

• Clarification on multiple occupancy buildings to be released as a Standata item
• For discussion at the conference on how other municipalities feel about this issue.

Background information:  When the Province went through all the issues in the last several years surrounding Secondary Suites and how the rules will work for building and fire codes, was the electrical discipline involved in those discussions?  Calgary would like to see not two services but perhaps an upstairs subpanel.   14-106 Location and grouping

Overcurrent devices shall be located in readily accessible places, except as provided for elsewhere in this Code, and shall be grouped where practicable.

Over time, overcurrent devices need maintenance, replacement, or resetting, so they must not be located where access is difficult. If they are not grouped together, it might be difficult to locate them when maintenance or replacement is required. Rule 14-106 requires that overcurrent devices be readily accessible and grouped, where possible, or be located as required by other Rules of the Code [e.g., Rule 6-102(3)].

Readily accessible

Capable of being reached quickly for operation, renewal, or inspection, without requiring those to whom ready access is a requisite to climb over or remove obstacles or to resort to portable ladders, chairs, etc.

                                             

                                                   2012 Annual Technical Conference

Agenda item # 2012ag-0000                 10-400-024 equipment bonding                  

                                                                                                                            

Submitted by: Don Bradshaw City of Airdrie

Question/enquiry:   When bonding the aluminum frame of Solar Photovoltaic module using tin plated lay in lugs, what is the correct sequence of installing the fasteners? What is most problematic to me is the misinformation published in the installation instructions provided by the PV module manufacturers.

Recommendation: For discussion.

Background information: 

WANT TO EXPAND THIS AREA WITH MORE INFO ON BONDING OF ALUMIMUM FRAME PRODUCTS FROM THE NABCEP INSTALLERS GUIDE

This suggested best practice is adapted from several sources - IAEA news Perspectives on PV Sept-Oct 2011; NABCEP PV installers guide; Homepower Magazine Q&A site; CE Code handbook for installing aluminum conductors;  several PV module manufacturers installation instructions.

 

 

 When using Ilsco GBL-4DBT (or similar) lay-in lugs as the module bonding method:

 

Module Frame surface preparation:

• The module frame is required to be bonded only at the point(s) where a designated bonding provision has been made by the manufacturer.
• The module frame must be prepared for the bonding lugs. Where electrical contact is made to an aluminum framed PV module, the clear coating anodizing and oxidation  (which are insulators) must be penetrated or removed before the bonding lug is installed. Code reference 10-600.
• A stainless steel brush should be used to remove any anodization or oxidation from the aluminum module frame
• A thin coat of anti-oxidant film (such as Penetrox) should be placed on the cleaned aluminum surface.

Fastener Installation:

• All hardware must be stainless steel, usually 8-32 or 10-32 machine screws are used.

• Do not place any washers (flat or lock) between the module frame and the lug to interfere with its electrical contact with the module frame.
• Do not place a lock washer in contact with the bonding lug as this is a violation of the listing for the lugs. The use of star washers on these lugs is often shown in the grounding instructions provided by the PV module manufacturers – this is incorrect information. Star lock washers on tin plated copper lugs will dig into the relatively soft copper of the plated lug which creates loss of compression force but most importantly they remove the tin plating which will expose the underlaying metal to corrosive/cathodic action.
• Proper installation typically requires a flat washer to be installed at the screw head. A lock (star) washer is used under the nut, in contact with the aluminum frame of the module. The lock washer not only locks the nut in place, it also improves electrical contact by penetrating the anodized coating of the aluminum frame of the module.
• The fasteners are to be torqued to provide the proper mechanical force to hold the electrically conductive parts together for the life of the installation. Torque value depends on bolt size, but will be around 20 to 25 inch-pound for a 10-32 bolt.