Location of control devices — are we consistent on this subject?

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Although “control devices” are not specifically defined in the Canadian Electrical Code, Part I, application of control devices is well-described throughout the Code, and particularly in Section 14.

Rule 14-010 provides fundamental requirements for automatic and manual control devices as follows:

“14-010 Protective and control devices required Electrical apparatus and ungrounded conductors shall, except as otherwise provided for in this Section or in other Sections dealing with specific equipment, be provided with (a) devices for the purpose of automatically opening the electrical circuit thereto,

(i) if the current reaches a value that will produce a dangerous temperature in the apparatus or conductor; and

(ii) in the event of a ground fault, in accordance with Rule 14-102;

(b) manually operable control devices that will safely disconnect all ungrounded conductors of the circuit at the point of supply simultaneously, except for multi-wire branch circuits that supply only fixed lighting loads or non-split receptacles, and that have each lighting load or receptacle connected to the neutral and one ungrounded conductor; and

(c) devices that, when necessary, will open the electrical circuit thereto in the event of failure of voltage in such a circuit.”

It is quite clear from this Rule of the Code that in general (unless allowed by specific exceptions), electrical equipment and ungrounded conductors must be provided with means of manual control (manual disconnecting means) and with means of automatic control (automatic disconnecting means which open the circuit upon overcurrent or upon a fault current).

Rule 14-100 (with a few exceptions) mandates that automatic control devices (i.e., overcurrent devices), must be installed as follows:

“14-100 Overcurrent protection of conductors (see Appendix B)

Each ungrounded conductor shall be protected by an overcurrent device at the point where it receives its supply of current and at each point where the size of conductor is decreased.”

Location of overcurrent devices is prescribed by Rule 14-106 as follows:

“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.”

It is interesting to note use of the terminology “readily accessible” in this Rule and in the Code requirements indicated below, as this terminology (readily accessible) and terminology “accessible” in application to the electrical equipment have different meanings.

The Code defines “accessible” in application to electrical equipment as follows:

“Accessible (as applied to equipment) — admitting close approach because the equipment is not guarded by locked doors, elevation, or other effective means.”

This definition means that when any Rule of the Code requires equipment to be “accessible,” the access must be made available to the equipment so that locked doors, fences, barriers, elevation or other similar means will not create obstacles for persons to get to such equipment.

The Code, however, defines “readily accessible” as follows:

“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.”

These definitions mean that the equipment may be located behind locked doors, fences, or barriers, but such obstacles will not prevent authorized staff with keys, access cards or similar tools from getting to the equipment. However, this definition also means that such qualified staff would not have to carry with them portable ladders, nor would they be forced to remove specific obstacles on their way to the equipment.

And what about location of control devices (automatic or manual disconnecting means) in general? Rule 14-406 provides the following answer:

“14-406 Location of control devices

(1) Control devices, with the exception of isolating switches, shall be readily accessible.

(2) Remotely controlled devices shall be considered to be readily accessible if the means of controlling them are readily accessible.”

As we now clearly understand the definition of “readily accessible,” we know that control devices, in general, could be located in any place (unless specifically restricted by the CE Code or by other relevant Codes and Standards), as long as authorized staff with keys, access cards or similar tools are not prevented from getting to the equipment without resorting to use of portable ladders or having to deal with removal of specific obstacles on their way to the equipment.

Does it mean that a circuit breaker located inside the distribution panel in the electrical room in one part of the building could function as a control device for a transformer located in another electrical room? The answer is a resounding “yes.”

What about disconnecting means for elevating equipment, motors in general, fire pumps or fire alarm systems?

Let’s check it out.

Rule 28-604 provides the following requirements for motor disconnecting means:

“28-604 Location of disconnecting means

(1) The motor branch circuit disconnecting means described in Rule 28-602(1)(a), (b), (c), and (d) shall

(a) be located at the distribution centre from where the motor branch circuit originates; and

(b) where intended to serve as a single disconnecting means for a motor branch circuit, motor, and controller or starter, also be

(i) located in accordance with Subrule (3); or

(ii) capable of being locked in the open position by a lock-off device approved for the purpose and be clearly labelled to describe the load or loads connected.

(2) The motor branch circuit disconnecting means described in Rule 28-602(1)(f) shall be located in accordance with Subrule (3).

(3) Except as required in Subrule (5), the motor and motor starter or controller disconnecting means shall be located

(a) within sight of and within 9 m of the motor and the machinery driven by it; and

(b) within sight of and within 9 m of the motor starter or controller.

(4) Notwithstanding Subrule (3), where a motor or group of motors is fed from a single branch circuit in which the branch circuit disconnecting means is not capable of being acceptably locked in the open position and where the motor disconnecting means is a manually operable across-the-line type of motor starter, the motor disconnecting means shall be permitted to be located beyond the limits defined in Subrule (3), provided that

(a) it is capable of safely making and interrupting the locked rotor current of the connected load;

(b) it is capable of being locked in the open position; and

(c) it can be demonstrated that the location specified in Subrule (3) is clearly impracticable.

(5) The motor disconnecting means for air-conditioning and refrigeration equipment shall be located within sight of and within 3 m of the equipment.

(6) The disconnecting means shall be readily accessible or have the means for operating them readily accessible.

(7) Motor-driven machinery of a movable or portable type for industrial use shall have a motor-circuit switch or circuit breaker mounted on the machine and accessible to the operator.”

This requirement is certainly based on the safety criteria, as disconnecting means for rotating machinery must be located within the site of such machinery, unless specific lockout procedures are implemented.

Rule 32-206 offers criteria for installation and location of the circuit breaker in the normal power supply circuit of the fire pump — immediately downstream from the service box as follows:

“32-206 Disconnecting means and overcurrent protection (see Appendices B and G)

(1) No device capable of interrupting the fire pump circuit, other than a circuit breaker labelled in a conspicuous, legible, and permanent manner identifying it as the fire pump disconnecting means, shall be placed between the service box and a fire pump transfer switch or a fire pump controller.

(2) The circuit breaker referred to in Subrule (1) shall be lockable in the closed position.”

Rule 38-051 governs location of disconnecting means for an elevator equipment as follows:

“38-051 Disconnecting means (see Appendix B)

(1) A single disconnecting means shall be provided for the opening of all ungrounded conductors of each of the following:

(a) the drive motor and its ventilation and control circuits in each elevator, escalator, dumbwaiter, or lift for persons with physical disabilities operating individually or as one of a group; and

(b) the branch circuit(s) supplying the lighting and ventilation, heating, and air conditioning in each car, and such circuit(s) shall not be controlled by the disconnecting means described in Item (a).

(2) Each disconnecting means shall be an externally operated fusible switch or a circuit breaker and shall be equipped with means for locking it in the open position.

(3) Where circuit breakers are used as a disconnect means, they shall not be opened automatically by a fire alarm system.

(4) Means shall be provided on the switch or circuit breaker to indicate the disconnected position.

(5) The disconnecting means shall be located where it is visible on entry to the machinery area and readily accessible to authorized persons.

(6) When the disconnecting means required by Subrule (1)(a) is not visible from, or is located more than 9 m from, the motor controller(s), an additional manually operable motor controller disconnecting switch, whose opening is not solely dependent on springs, shall

(a) be installed so that it is visible from, or adjacent to, the remote equipment;

(b) open all ungrounded conductors; and

(c) be capable of being locked in the open position.

(7) (a) Driving machines or controllers other than motor controllers not within sight of the disconnecting means shall be provided with a manually operated switch installed in the control circuit to prevent starting.

(b) The manually operated switch(es) shall be installed adjacent to this equipment.

(8) Where there is more than one driving machine in a machine room, the disconnecting means shall be numbered to correspond to the identifying number of the driving machine that it controls.

(9) The disconnecting means shall be provided with a sign to identify the location of the supply side overcurrent protective device.

(10) (a) No provision shall be made for automatically closing this disconnecting means.

(b) Power shall be restored only by manual means.

(11) The disconnecting means serving an escalator or moving walk controller shall be installed in the same location as the controller.

(12) Where multiple driving machines are connected to a single elevator, escalator, moving walk, or pumping unit, there shall be one disconnecting means to disconnect the motor(s) and control valve operating magnets.

(13) Where the driving machine of an electric elevator, dumbwaiter, material lift, or lift for persons with disabilities or the hydraulic machine of a hydraulic elevator, dumbwaiter, material lift, or lift for persons with disabilities is located in a remote machine room or remote machinery space, or the motor-generator set is located in a remote machine room or remote machinery space, a single means for disconnecting all ungrounded main power supply conductors shall be provided that is visible from the machine and capable of being locked in the open position.”

Location of disconnection means for a high voltage station are prescribed by Rule 36-214 as follows:

“36-214 Disconnecting means

(1) Where conductors fed from a station enter a building, either

(a) a load-breaking device shall be installed indoors at the entry of the conductors to the building; or

(b) a load-breaking device at the supply station shall be capable of being tripped or operated from within the building.

(2) Unless of the draw-out type, each circuit breaker and each load-break switch having contacts that are not visible for inspection in the open position shall be provided with a group-operated isolating switch on the supply side that shall be

(a) provided with the means for adequate visible inspection of all contacts in both the open and closed position;

(b) interlocked so that it cannot be operated under load; and

(c) provided with positive position indicators.

(3) Where more than one source of voltage exists in a station consisting of two or more interconnected sections operating at high voltage or where there is another possibility of feedback, a visible point of  connection meeting the requirements of Subrule (2) shall be provided in all circuits where the possibility of feedback between sections exists.”

And what about control devices for a dwelling unit? Do they have to be inside that dwelling unit or could they be installed in areas outside the dwelling unit?

Rule 26-400 has the answer which states that every dwelling unit must have a panelboard with control devices for the loads in that particular dwelling unit. The only exception from this requirement applies to the dwelling units in hotels and motels or to dwelling unit which are created by a subdivision of single dwelling and which are not individually metered for consumption of power (see below):

“26-400 Panelboards in dwelling units (see Appendix B)

(1) A panelboard shall be installed in every dwelling unit except for dwelling units in hotels and motels, and dwelling units that

(a) are not individually metered for electrical power consumption; and

(b) have been created by subdivision of a single dwelling.

(2) Every panelboard installed in accordance with Subrule (1) shall have a single supply protected by overcurrent devices and this supply shall be capable of being disconnected without disconnecting the supply to any other dwelling unit.“ 

Although the CE Code has other specific examples of required control devices locations or other necessary conditions for devices controlling specific types of equipment, this discussion will be limited to one more such example – to disconnecting means and overcurrent devices for power supply to a fire alarm system, as shown below:

“32-108 Power supply

(3) Overcurrent devices and disconnecting means for the separate circuit supplying a fire alarm system shall be clearly identified as the fire alarm power supply in a permanent, conspicuous, and legible manner, and the disconnecting means shall be coloured red and be lockable in the ON position.”

And spaking of fire alarm system control devices, how about location of fire alarm manual stations or emergency telephones?

The CE Code users will not find these requirements in the CE Code, but cross-reference in Appendix G of the CE Code to the applicable provisions of the National Building Code of Canada (NBCC) will help the CE Code users to find the relevant NBCC provisions.

Article 3.2.4.16. of the NBCC 2015 offers the following:

“3.2.4.16. Manual Stations

1) Except as permitted by Sentences (2) and (3), where a fire alarm system is installed, a manual station shall be installed in every floor area near

a) every principal entrance to the building, and

b) every exit.”

Article 3.2.4.22. provides the following statements in respect to location of fire alarm systems’ emergency telephones intended to be operated by authorized personnel:

“3.2.4.22.(5) The 2-way communication system referred to in Clause (1)(a) shall be installed so that emergency telephones are located in each floor area near exit stair shafts.”

It is interesting to note that Rule 2-122 of the CE Code 2015 references Article 3.8.1.5. of the NBCC 2010 in Appendix G – in respect to the mounting height of control devices.

In 2018 edition of the CE Code, such reference will be made in Appendix G to Articles 3.8.2.6. and 3.8.3.8. of the NBCC 2015.

These NBCC Articles mandate the following height of control devices:

“3.8.2.6. Controls

1) Except as provided in Sentence 3.5.2.1.(3), controls for the operation of building services or safety devices, including electrical switches, thermostats, faucets, door hardware and intercom switches, that are intended to be operated by the occupant and are located in or adjacent to a barrier-free path of travel shall comply with Subsection 3.8.3.

3.8.3.8. Controls

1) Controls described in this Section shall

a) where located in or adjacent to a barrier-free path of travel, and unless otherwise stated,

i) be mounted 400 mm to 1 200 mm above the floor,

ii) be adjacent to and centered on either the length or the width of a clear floor space of 1 350 mm by 800 mm.”

This means that in order to be accessible to all occupants, such control devices cannot be placed higher than 1200 mm.

It is interesting to note that 2014 edition of ULC S524, (the standard that governs installation provisions for fire alarm system devices), has amended such height requirement for manual stations – to be consistent with the NBCC accessibility provisions as follows:

“ 8.1 MANUAL STATIONS

8.1.1 Manual stations shall be installed 1050 mm to 1150 mm above the finished floor level measured from the centre of the manual station.”

And what about mounting height of the fire alarm emergency telephones?

Let’s take a look at Clause 6.3.2 of ULC S524:

“6.3.2 Telephone handset enclosures shall be installed in an accessible location between 1350 mm and 1500 mm above the finished floor level measured to the centre of the enclosure.”

It appears that ULC S524 creates a conflict with accessibility provisions of the NBCC, as it mandates mounting height of the emergency telephones between 1350 mm and 1500 mm. Not necessarily, as the NBCC accessibility provisions apply to the building occupants, and the ULC S524 requirements for mounting height of emergency phones is intended to authorized personnel (i.e., to emergency respondents).

Let’s check out another interesting requirement of the NBCC for location of a very specific control device – for a manual switch to silence audible signal device located in a dwelling unit:

“3.2.4.18.(7) Except as permitted by Sentence (11), audible signal devices located within a dwelling unit shall include a means for them to be manually silenced for a period of not more than 10 min, after which time the devices shall restore themselves to normal operation.”

Although the general provisions of ULC S524 do not allow audible signal devices to be installed less than 2300 mm above the finished floor, the ULC S524 provisions for mounting of audible devices in dwelling units take into account the NBCC accessibility requirements to control devices:

“9.3.1 Where silencing means are separately  installed or incorporated in the audible signal device, the silencing means shall be clearly identified and installed 1050 mm to 1150 mm above the finished floor level measured from the centre of the silencing means.”

These few examples of various provisions for location of control devices clearly demonstrate that the CE Code users need to review all other relevant requirements of the applicable Codes and standards in order to meet safety and performance objectives of the legally adopted codes.

And as usual,  local AHJs should always be consulted as necessary.

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Ark Tsisserev is president of EFS Engineering Solutions, Ltd., an electrical and fire safety consulting company, and is a registered professional engineer with a master’s degree in Electrical Engineering. Prior to becoming a consultant, Ark was an electrical safety regulator for the city of Vancouver. He is currently the chair of the Technical Committee for the Canadian Electrical Code and represents the CE Code Committee on the CMP-1 of the National Electrical Code. Ark can be reached by e-mail at: ark.tsisserev@efsengineering.ca His company web site is: http://www.efsengineering.ca

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