Network Customer Built Transformer Vault Guideline · Network Customer Built Transformer Vault Guidelines Last Revised: ... LIGHTING AND DUPLEX RECEPTACLES ... To ensure that the

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Electrical Engineering

Network Customer Built Transformer Vault Guidelines

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ENMAX Power Corporation (EPC)


Last Revised: January 2, 2014

Electrical Engineering ENMAX Power Corporation (EPC)

141 - 50 Ave. SE Calgary, Alberta T2G 4S7 Important - Please note the following: If there is any inconsistency between this document and any applicable EPC tariff or agreement, the terms of that tariff or agreement will prevail. The contents of this document are provided for information purposes only. The information contained within this document is not binding on EPC and can be modified by EPC without notice.

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January 2, 2014 Page i

TABLE OF CONTENTS

1. INTRODUCTION................................................................................................................. 1 1.1 Purpose of This Guideline............................................................................................................... 1 1.2 Types of Transformers To Be Used ................................................................................................ 2 1.3 Easements ....................................................................................................................................... 2 1.4 Customer Checklists ....................................................................................................................... 2

2. DESIGN GUIDELINES FOR STRUCTURES AND FACILITIES ................................ 3 2.1 Location of Customer Built Transformer Vault .............................................................................. 3 2.2 Customer Built Transformer Vault Dimensions ............................................................................. 4 2.3 Location of Emergency Disconnect Device Room ......................................................................... 4 2.4 Electrical Load Criteria for Customer Built Vaults......................................................................... 5 2.5 Grounding Of Transformer Vaults.................................................................................................. 5 2.6 Customer Equipment Bonding........................................................................................................ 6 2.7 Painting ........................................................................................................................................... 6 2.8 Vault and Emergency Disconnect Device Room Wall Construction.............................................. 6 2.9 Floor/Ceiling Loading Weights....................................................................................................... 6

3. EQUIPMENT AND PERSONNEL ACCESS REQUIREMENTS .................................. 7 3.1 Air Testing ...................................................................................................................................... 7 3.2 Equipment Access........................................................................................................................... 7 3.3 Lift Out Well Equipment Access .................................................................................................... 8 3.4 Equipment Access Door Ramp Requirements ................................................................................ 8 3.5 Personnel Access Doors.................................................................................................................. 9

4. LIQUID CONTAINMENT ................................................................................................ 10 4.1 Door Sill........................................................................................................................................ 10 4.2 Drainage System ........................................................................................................................... 10 4.3 Sump Pits And Covers .................................................................................................................. 10

5. FIRE PROTECTION AND DETECTION....................................................................... 12 5.1 Alarms........................................................................................................................................... 12 5.2 Smoke and Heat Detectors ............................................................................................................ 12 5.3 Sprinkler Systems ......................................................................................................................... 12 5.4 Fire Rated Walls ........................................................................................................................... 13 5.5 Fire Rated Doors ........................................................................................................................... 13 5.6 Fire Dampers................................................................................................................................. 13 5.7 Fire Extinguishers ......................................................................................................................... 13

6. LIGHTING AND DUPLEX RECEPTACLES................................................................. 14 6.1 General Room Lighting And Duplex Receptacle Requirements .................................................. 14 6.2 Emergency Lighting And Duplex Receptacles ............................................................................. 14

7. VENTILATION SYSTEM................................................................................................. 15 7.1 Customer Built Indoor Vaults ....................................................................................................... 15 7.2 Emergency Disconnect Device Room .......................................................................................... 16

8. DOCUMENTATION HISTORY ...................................................................................... 17

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January 2, 2014 Page ii


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January 2, 2014 Page 1 of 17

1. INTRODUCTION

1.1 Purpose of This Guideline

In Calgary, unlike many other cities, the customer has the option of constructing the building’s transformer vault. To ensure that the integrity and quality of service of the network system is maintained, the Electrical Engineering section has written this guideline that lists the basic procedural and technical requirements that must be met in the construction of the customer built vault.

The term “Network,” as it is used in this publication, refers to the area of EPC’s electrical distribution system that is located in Calgary’s downtown core and portions of the adjacent communities (see Network Boundary Map).

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Please note the following:

For all other aspects of Network servicing, please refer to the Network Servicing Policies and Guidelines

This guideline does not exempt the customer from the City of Calgary building codes.

Prior to any construction that will affect EPC’s Network system EPC requires a site coordination meeting. At the meeting, an ENMAX Network representative will review, with the project manager, any outstanding conflicts that will need to be corrected prior to the beginning of the construction of the vault. The EPC Network coordinator will then establish a tentative schedule for construction that will commence when the customer meets all the requirements in the Network guidelines.

1.2 Types of Transformers to Be Used

The transformers that are used in the customer built vault are filled with an insulating fluid that is approved for indoor application. EPC will supply and install the transformers at the customer’s expense.

1.3 Easements

Please contact the EPC Electrical Engineering section for further details.

EPC requires the customer to grant a general easement to EPC for the customer built transformer vault, the emergency disconnect room, and the associated conduit system. The conduit system includes the conduit connecting the customer built vault(s) to the external EPC system.

1.4 Customer Checklists

Checklists for the construction and energization of the customer transformer vault and Emergency Disconnect Device room can be obtained from the EPC Network Coordinator at (403) 514-2917. Failure to have the respective checklist signed off by the EPC Network Coordinator may result in a delay in the construction or energization of the transformer vault.

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2. DESIGN GUIDELINES FOR STRUCTURES AND FACILITIES

2.1 Location of Customer Built Transformer Vault

The customer built transformer vault must be located in a manner so that EPC is provided with the following:

There are two (2) access points. EPC personnel must have 24 hour direct access from outside the building via one of the access points. Direct access, 24-hours a day, is necessary so that EPC personnel can perform emergency and/or routine switching and maintenance on the ENMAX system without delays.

The installation of equipment access doors meet all of the conditions outlined in Section 3. Access Requirements and/or the installation of a standard EPC vault steel hatch and slab assembly.

Sufficient space in the area immediately outside of the customer built transformer vault to allow EPC work vehicles to maneuver.

The customer built transformer vault must be located on the customer’s property and cannot be located above the +15 level of the building.

Grade level vault locations will require the following additional requirements:

o A flat level platform that will eliminate any grade deviation between the floor of the vault and the outside grade level (2.1 meters (W) x 3.0 meters (L)).

o The platform must be

removable for storage inside of the vault for future equipment removal or installation

light enough to be carried by 2 men without the aid of a mechanical device

able to temporarily attach to the building to avoid any movement during use

Capable of handling the weight of the network transformer (Engineering drawing that is stamped and signed by a professional engineer)

Smooth surface that will permit the use of an air pallet device

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2.2 Customer Built Transformer Vault Dimensions

The size of the customer built transformer vault must be large enough to house a minimum of four (4) Network style transformers with protectors. There must also be enough room to permit safe operation of the equipment by EPC Network staff and allow for safe removal of the equipment if required.

The minimum internal dimensions for a customer built transformer vault are shown in the table below. Also, see EPC drawings 536-1010-202/203/211 in the Appendix.

Typical Internal Vault Dimensions

(L x W x H)

5m x 11m x 4.5m (120/208 - volt)*

5m x 11m x 4.5m (277/480 - volt)*

11m x 12m x 4.5m (347/600 - volt)*

*These dimensions exclude the space requirement for the mechanical ventilation equipment.

Please contact the EPC Electrical Engineering section regarding any vault for 347/600 volts.

2.3 Location of Emergency Disconnect Device Room

EPC requires an emergency disconnect device room that contains the equipment that will disconnect the EPC primary cable system from the transformers in the event of an emergency. To facilitate access to a building during an emergency, it is essential the emergency disconnect devices be installed at a location that is always accessible to EPC crews.

The emergency disconnect device room must be located in a manner so that EPC is provided with the following:

24-hour direct access from outside the building.

may be incorporated as part of the customer built transformer vault lift out well. Please contact the EPC Electrical Engineering section for details.

when the emergency disconnect device room cannot be incorporated into the customer built transformer vault lift out well the customer has 2 options:

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construction of a room inside the building that meets the access ـrequirements under section 3.(2.5 meters (W) x 5.0 meters (L) x 2.1 meters (H))

an external underground chamber constructed by EPC on ـcustomer property with minimum internal dimensions of 2.4 meters (W) x 3.6 meters (L) x 2.1 meters (H).

EPC will supply and install the emergency disconnect devices, at the customer’s expense.

2.4 Electrical Load Criteria for Customer Built Vaults

The following table outlines the maximum aggregate service panel size that can be connected to a customer built vault at the given voltages.

Design Criteria for Customer Built Vaults (Maximum Allowable Service Size)

Secondary Voltage (Volts)

Transformer Size (kVA) Maximum Aggregate Service Panel Size

(amps)

120/208 750 7,600

120/208 1000 8,800

277/480 750 2,800

277/480 1000 3,600

277/480 1500 6,000

277/480 2000 7,600

347/600 2500 8,000

2.5 Grounding of Transformer Vaults

For the protection of EPC staff, a ground grid is required for all indoor customer built vaults. The location of the ground grid has to be either under the lift out well or the first EPC structure external to the building. The ground grid must be installed as shown in drawing 536-1200-001.

EPC will verify and record the impedance value of the ground grid before energizing the EPC equipment.

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2.6 Customer Equipment Bonding

It is the customer’s responsibility to bond any metallic component that extends into public space. The customer must install his own ground plate in the indoor vault room and connect the ground plate to the building’s ground grid.

2.7 Painting

The customer is responsible for painting all of the interior vault surfaces, emergency disconnect device room (if applicable) and lift out well including the ceiling and floors. All floors must be smooth and free of irregularities to permit the use of air-pallet equipment. Non-slip surfaces are NOT to be installed on any floors. The color of the paint must be white and be latex based.

2.8 Vault and Emergency Disconnect Device Room Wall Construction

The walls of the customer built vault and emergency disconnect device room (if applicable) must be a “cast in place” concrete with a fire resistant rating of not less than 3-hours.

2.9 Floor/Ceiling Loading Weights

The customer is responsible for ensuring that the floor and/or ceiling load ratings are capable of supporting the EPC installed equipment. The table below outlines the approximate weights for transformers and the associated secondary buss work and cables.

ENMAX Power Standard Weights (per Transformer with Protector)

Service Voltage Base Footprint

(W x L)) Unit Weight

120 / 208 Volts 1.3m x 1.6m 6500kg

277 / 480 Volts 1.5m x 1.6m 9000kg

347 / 600 Volts 1.4m x 2.1m 10000kg

Secondary Buss Work and Cables

N/A 2000kG

*The base footprint is not the same as the transformer dimensions and the secondary buss work and cables are supported via I-beams mounted to the walls

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3. EQUIPMENT AND PERSONNEL ACCESS REQUIREMENTS

EPC personnel must have 24-hour access via one of the access points. This access must be directly from the outside of the building and not require the permission or assistance of a third party such as building security or the fire department.

A minimum of two (2) access points at the floor grade of the vault are required and (1) access point at floor grade for the emergency disconnect device room (if applicable).

Note: EPC will be installing signage on the customer side of the doors to the electrical vault room (see Appendix section for details).

3.1 Air Testing

Provision to test the air quality of the indoor vault, lift out well or emergency disconnect room will be required. The testing method must be such that opening of the door or lid is not required. Contact EPC Electrical Engineering for details.

3.2 Equipment Access

Either a ceiling or wall access design may be used to provide the entrance to install the EPC electrical equipment in the vault.

An outside ceiling access to the customer built transformer vault room can be built by installing a standard EPC vault steel hatch and slab assembly. Please contact the EPC Electrical Engineering section for details.

This assembly is installed in the portion of the customer built transformer vault room roof that is outside the building. The minimum overhead clearance at the slab assembly is 7.62 meters.

EPC will supply the vault steel grates and slabs but it will be at the customer’s expense.

The ceiling access can be combined with the emergency disconnect device vault for equipment access.

The wall style equipment access door must meet the following requirements:

The minimum internal dimension for the wall access equipment doors is 2.1 meters wide x 2.743 meters high. Typically this is a double door without a centre piece. Doors must swing out from the transformer vault room and the emergency disconnect device room (if applicable).

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The equipment access doors must either be equipped with removable door hinge pins so the doors can be taken off of their hinges or the doors must be able to open a full 180 degrees.

Each of the equipment access doors must accept a Best lock system and EPC will supply the cores and retain the keys. The equipment access door must be equipped with a pull style “D” handle, panic bar that has active trim and a night latch. A copy of the proposed door hardware specification accompanied by a drawing showing the door swing and pinning is to be submitted to the Network Coordinator prior to the customer ordering the material.

3.3 Lift Out Well Equipment Access

When a transformer vault is constructed below grade, a lift out well is required for the removal of EPC equipment. The minimum size for the lift out well is shown on drawing 536-1010-207 in the Appendix. To safely remove equipment from the vault, a minimum overhead clearance of 7.62 meters, above the removable concrete slabs, is required.

The preferred location of the lift out well is the outside of an exterior wall of the building and adjacent to the transformer vault.

The lift out well must be equipped with a sump pit (please see Section 4.3 - Sump pit and cover). The sump pit must have a perforated cover and a removable hatch with a minimum diameter of 0.2 meters to allow for pumping out any liquid.

A pump will be supplied by EPC. It will be connected to the building storm system. The sump pump connection to the building and liquid discharge into the storm system must be covered by an appropriate agreement between the building owner and EPC.

The lift out well must drain towards the sump pit.

The location of the sump pit must be approved by the EPC Electrical Engineering section before construction.

3.4 Equipment Access Door Ramp Requirements

This subsection which discusses concrete ramps and removable sills, applies ONLY to the customer built vaults that do not have an attached lift out well.

The purpose of the concrete ramp or removable sill at the equipment access doorway is to confine the oil or transformer liquid in the case of a leak from one transformer (drawing #536-1010-208 in the Appendix). The EPC Electrical Engineering section will provide details on the volume of liquid that must contained which are based on the type of units being installed. The following requirements must be adhered to:

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The concrete ramp at the equipment access doorway must have a height of 100mm at the centre.

The ramp must have a gradual slope on each side of the doorway with a minimum span of 1.0 meter.

3.5 Personnel Access Doors

EPC personnel must have 24-hour access via one of the access points. This access must be from outside of the building and lead directly into the vault when the customer built transformer vault is not equipped with a lift out well.

For locations where the emergency disconnect device chamber is a room, the access must be from outside of the building and lead directly to the emergency disconnect device room.

If the access to the personnel doors of the customer built vault room is via the ceiling, a fixed in place EPC ladder is required to permit access via the grates. EPC will supply the ladder at the customer’s expense. Installation of the ladder may only be performed by EPC personnel and at a time deemed appropriate by the EPC coordinator.

Wall located personnel access doors must include the following items:

The personnel access doors shall have dimensions of 0.91 meters wide x 2.1 meters high.

Entrance hardware that will accept a Best lock 7-pin core. A Best lock 1E rim cylinder is typically used – EPC will supply the cores and retain the keys.

A pull style “D” handle, panic bar that has active trim and a night latch. A copy of the proposed door hardware specification accompanied by a drawing showing the door swing is to be submitted to the Network Coordinator prior to the customer ordering the material.

A concrete sill with a minimum height of 100mm. The sill must be high enough to confine oil or transformer liquid in the case of a leak or spillage from one transformer (drawing 536-1010-208 Detail 2 in the Appendix). The EPC Electrical Engineering section will provide details on the volume of liquid to be contained based upon the units being installed.

The door may be alarmed if required by the customer. The supply and installation of any building security related equipment is the responsibility of the customer.

If the personnel access door does not open into public space, the next door must also be equipped with a panic bar.

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4. LIQUID CONTAINMENT

4.1 Door Sill

All access points to the customer built transformer vault room must be equipped with a concrete sill (drawing 536-1010-208 Detail 2 in the Appendix).

Locations with equipment access doors must be equipped with a removable sill supplied by EPC (drawing 536-1010-208 Detail 4 in the Appendix)

4.2 Drainage System

4.2.1 Customer Built Transformer Vault Room

The floor of the transformer vault room must drain towards equipment access doors as seen in the drawing 536-1010-208 in the Appendix. Please contact the EPC Electrical Engineering section for approved locations for the dry sump pit (0.3 x 0.3 x 0.3 meters).

Lift out well drainage may be designed as a floor drain connected to the buildings Storm water system. An agreement between EPC and the building owner is required to cover the connection. An alternate design consisting of a dry sump (0.6 x 0.6 x 0.6 meters) may be considered.

4.2.2 Emergency Disconnect Device Room

Floor drains are not allowed in the emergency disconnect device room.

4.3 Sump Pits and Covers

When the sump pit is connected to the building’s storm water system, the lift out well sump pit must be designed with a passive flow drainage system.

When the lift out well sump pit is not connected to the building’s storm water system then the sump pit must be large enough to contain 200 litres of liquid.

To maintain safety and still ensure ease of entrance into the sump pit, the sump pit must be equipped with a removable steel cover with a minimum thickness of 6.35mm. For stand alone systems (no storm water connection) the lid must have a separate hinged or

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removable cover 0.3 meter in a diameter to facilitate the insertion of a pump hose for liquid removal.

The sump pit cover must be perforated to permit liquid to enter the sump pit.

The sump pit within the vault must be 0.3 meters in depth. All joints must be properly sealed to prevent any leakage. As part of the design a method must be included for the removal of any liquid. For sump pits with storm water connection, an oil containment system must be provided.

For safety and ease of maintenance, the sump pit must be equipped with a removable steel cover with a minimum thickness of 6.35mm. The cover must be perforated to allow liquid to enter the sump pit.

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5. FIRE PROTECTION AND DETECTION

5.1 Alarms

EPC does not require alarms within the vault. The location and type of alarms deemed necessary by the customer must be approved in advance by the EPC Electrical Engineering section.

5.2 Smoke and Heat Detectors

Each room of the customer built transformer vault must be equipped with two (2) ceiling mounted heat detectors and two (2) smoke detectors. The detectors must be located so that there is a smoke detector between each pair of Network transformers. The specific location for each project must be confirmed by EPC Electrical Engineering in advance. This will provide detection of overheating or potential hot spots.

If the emergency disconnect device room is inside the building but not part of the lift out well, the room must be equipped with (1) ceiling mounted heat detector and (1) smoke detector.

All of the smoke and heat detectors must be connected to the building alarm system and actuate the main building alarm if fire or overheating occurs in the vault room. EPC requires access to the alarm points so its staff can install an additional connection to the EPC monitoring system. The following requirements must be adhered to:

The alarm points (EPC use) must be dry contacts.

Smoke detectors must be configured to disable the ventilation system when activated.

Heat detectors must be equipped with an alarm point (EPC use) at 40o

Celsius to indicate room high temperature.

5.3 Sprinkler Systems

If the City of Calgary building code stipulates that the customer must install a sprinkler system, then the following is required:

A non-pressurized, dry type, sprinkler system.

The approval of the EPC Electrical Engineering section for the location of the sprinkler heads.

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5.4 Fire Rated Walls

The floors, ceiling and walls of the customer built transformer vault room and emergency disconnect device room (if applicable) must be “cast in place” concrete that has a fire resistant rating of not less than three (3) hours.

Special consideration will be given to proposals for different ceiling materials and must be approved by EPC Electrical Engineering prior to construction.

5.5 Fire Rated Doors

In those locations where the customer built transformer vaults and emergency disconnect device room have wall access style personnel and equipment access doors, the doors must have a fire resistant rating of not less than two (2) hours.

5.6 Fire Dampers

When an intake or exhaust outlet is not on an exterior building wall, the outlet must have a fire damper rated for a minimum of two (2) hours.

5.7 Fire Extinguishers

EPC field staff will be responsible to supply and mount a fire extinguisher beside each vault doorway and the entrance/exit of the emergency disconnect device room (if applicable).

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6. LIGHTING AND DUPLEX RECEPTACLES

6.1 General Room Lighting and Duplex Receptacle Requirements

The customer is responsible for the cost of supplying and installing the general room lighting and duplex receptacles, in accordance with the following EPC standards (see the Appendix section for further details). Note all lighting and power is to be on a generator equipped circuit. Note that the general room lighting must be rated for temperatures down to 0 degrees Celsius.

Typical Customer Built Vault Lighting Standard for Customer – 208 or 480 Volt (536-1010-211).

Typical Customer Built EDD Room Lighting Standard (536-1220-100).

Note that vault lighting for 600-volt vault rooms must be submitted to EPC Electrical Engineering in advance.

6.2 Emergency Lighting and Duplex Receptacles

The customer is responsible for the cost of supplying and installing the emergency lighting for the customer built vault and the emergency disconnect device room (if applicable). Note that the general room lighting must be rated for temperatures down to 0 degrees Celsius

An emergency exit sign and battery powered emergency light will be located directly above each point of exit.

In locations where the emergency exit from the indoor vault leads into a second room, the customer will install a 24-hour light in the second room.

The installation of these emergency services must comply with drawings 536-1010-211, for the indoor customer vault, and 536-1220-100, for an Emergency Disconnect Device Room (if applicable).

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7. VENTILATION SYSTEM

7.1 Customer Built Indoor Vaults

The customer built transformer vault must have both sufficient heat and ventilation to prevent the ambient air temperature from falling below freezing (0 degrees Celsius) or exceeding +40 degrees Celsius (CEC 2-318, 2009). Typical transformer heat losses for EPC equipment, on a per transformer basis, are listed in the following table.

EPC Standard Heat Loss (per Transformer)

Service Voltage Transformer Size Transformer Loss

120 / 208 Volts 500kVA 7000 Watts

120 / 208 Volts 750kVA 8000 Watts

120 / 208 Volts 1000kVA 12000 Watts

277 / 480 Volts 750kVA 8000 Watts

277 / 480 Volts 1000kVA 11000 Watts

277 / 480 Volts 1500kVA 12000 Watts

277 / 480 Volts 2000kVA 14000 Watts

347 / 600 Volts 2500kVA 19000 Watts

A typical ventilation system will be comprised of a passive air intake opening, an exhaust fan, and exhaust opening. The location of the air intake and exhaust system inlet must maximize the air flow across the EPC transformers. Location of all ventilation equipment requiring routine maintenance must be located external to the room to facilitate the maintenance activity. Note that the annual testing and maintenance of the ventilation system and components (air filters, motors, etc.) is the responsibility of the building owner.

The air intake must provide fresh outside air (non parking lot) and be covered by louvers, a bird screen, and include an air filter. The air filter(s) must be a common standard size,

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disposable, available locally, and may be required to meet the City of Calgary’s current building codes and have a two hour rated fire damper.

To ensure a safe and efficient outlet for the exhaust air, the exhaust outlet must be installed in a place that will not allow the room exhaust to be drawn into the vault air intake. For this reason the location of the exhaust outlet cannot be in the lift out well. The exhaust system outlet must be covered by louvers and a bird screen. A two hour fire rated damper may be required for the exhaust opening to meet the City of Calgary’s current building codes.

It is the customer’s responsibility to supply and install the control panel and supply the energy to power all the ventilation related equipment within the transformer vault. The control panel must be installed at the designated 24-hour access point which has been reviewed by the EPC Electrical Engineering section. The control panel must have a manual off, manual on, and an automatic position. The switch must have a light that indicates the status of the ventilation equipment.

The design of the ventilation equipment is the responsibility of the customer. The ventilation equipment must meet current building regulations and be approved by the City of Calgary Building Inspection Division.

Prior to construction, a copy of the plans of the physical layout for the ventilation equipment must be submitted to EPC Electrical Engineering for review and approval.

7.2 Emergency Disconnect Device Room

Ventilation is not allowed in the emergency disconnect device room.

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8. DOCUMENTATION HISTORY

Date Description of Changes August 31, 2011 Updated document format; changes to section 2.2 and 2.9 January 2, 2014 Updated document format

Documents

Network Customer Built Transformer Vault Guideline · Network Customer Built Transformer Vault Guidelines Last Revised: ... LIGHTING AND DUPLEX RECEPTACLES ... To ensure that the