Transcript
ELECTRICAL DESIGN CRITERIA
A. Normal Power Distribution System
1. For existing facilities, the consultant shall visit the site, determine the present load conditions (max. demand) and provide detailed information on the existing service including voltage/phases, switchgear, number of conductors, conduit size, etc. The consultant shall coordinate with FPL regarding the existing load plus the load that had been added to determine if the existing FPL transformers and/or vault need to be replaced. In existing facilities, when the FPL service is upgraded the consultant shall determine if the existing switchgear AIC rating is appropriate. For new facilities, the consultant shall coordinate with FPL to determine the characteristics of the new service based on his preliminary load analysis. It is the standard of the School Board of Broward County (SBBC) to provide an FPL vault in all new facilities. Pad mounted FPL transformers will be considered at owners discretion on a case by case basis. For new FPL vaults the consultant shall contact FPL for their requirements. Contact Mr. Paul C. “Chico” Harlacher at (954) 717-2076. For existing and new facilities, provide the following information on the working drawings. a. Power Distribution System: Indicate the following characteristics: Voltage _________ Phases _________ Wires _________Ampacity _________ b. Service Point: Vault _________ Coordinate with the Design Criteria Professional to obtain the standard vault specs and details as developed by the SBBC Design Services Section and FPL. c. Main Distribution: (1) Free standing switchboard/fusible/breakers. (2) Distribution panel/fusible/breakers. (3) Surge Protection - Manufacturer and characteristics. (4) Short circuit bracing for new switchboards d. Fault Current: Provide fault current analysis in symmetrical RMS amps at specified voltage. e. Grounding System: (1) (2) (3) (4) (5) f. g. h. i. Connect to Building Steel Water system Driven ground system (minimum of two 3/4" x 10 feet) Connect the telephone equipment room ground to the service ground system. Note: Chemical ground rods "XIT" can be considered for those installations where soil conditions make it difficult to obtain low resistance values when standard ground rods are used. Provide a dedicated room for the main switchboard. Ensure that this room opens to the exterior. Provide dedicated electrical rooms throughout the facility. No storage shall be allowed in electrical rooms. Provide voltage drop computations for all large feeders. For existing facilities, the consultant shall test the existing grounding system and provide a field LOG report for evaluation by the SBBC Design Services Section.
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B. Emergency Power System
1. Emergency power for facilities shall be such that in the event of failure of the normal supply to, or within the building or group of buildings concerned, emergency lighting, emergency power of both will be available within the time required for the application but not to exceed ten (10) seconds. The supply system for emergency purposes shall be permitted to comprise one or more of the types of systems described below. a. Systems required as per Article 700 of the National Electric Code (NFPA-70).
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
b. c. d. e. f. 2.
Storage batteries. Generator set. Uninterruptible power supplies. Separate service. Connection ahead of service disconnecting means.
Emergency Generator on Site: a. Specify: KW Rating _______ Voltage _______ Phases _______Wires _______ b. Connect the following systems to the emergency generator: (1) Andover System Panel (EM/S) (2) Cooler/Freezer/Ice Maker/Reach in Refrigerators (3) Dedicated outlets (4) Emergency Lighting (5) Fire Alarm System (6) Intercom System (7) Main Telephone Board (8) Security System (9) UPS System (10) Combination fire/smoke, fire and smoke dampers. The consultant shall obtain from the SBBC information as to whether the school is an EHPA shelter or a Special Needs EHPA shelter. Special needs EHPA shelters have greater requirements and thus the generator needs to be sized accordingly.
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No Emergency Generator on Site: a. Provide connection ahead of the main for fire alarm system. b. Battery lights connected to local lighting circuit ahead of any switching. c. Inverter packs for fluorescent lamps connected to local lighting circuit ahead of any switching. d. Self-powered exit signs connected to local lighting circuit ahead of any switching. e. Provide battery back-up for the fire alarm system. f. Separate electrical service with automatic switch over by the utility. g. Connect the intercom system and main telephone board to the UPS System.
C. Site Distribution
1. Systems: Routing of all listed systems is required. a. Normal lighting and power b. Emergency lighting and power c. Fire Alarm d. Intercom e. Television f. Telephone g. Security h. Energy management i. Electrical Service j. Telephone Service k. Computer Networking
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
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Closed Circuit Television
Installation: a. Underground: (1) (2) (3) Individual raceways Ductbank Manholes/Handholes sized by NEC 370-28. Provide separate manholes for normal power, emergency power and communications. (4) Grounding
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One Line Diagram (Power): Indicate the existing installation and new system(s).
D. Lighting
1. Ensure all new construction complies with this section and the building codes referenced elsewhere in these rules. a. Illumination of Means of Egress: Provide illumination of each means of egress under provisions with this rule for every educational plan. For the purposes of this rule, means of egress includes designated stairs, aisles, corridors, ramps, escalators, covered walkways and other passageways leading to the public right of way. (1) Ensure illumination of means of egress is continuous during the time that the building is occupied. Utilize lighting at such places for such time as required to maintain the illumination to the minimum required foot-candles. (2) Illuminate means of egress at all points including angles, intersections of corridors, passageways, stairways, ramps, landings and exit door to a minimum of not less than one (1) footcandle, measured at the floor. In auditoriums and other places of assembly, the illumination at the floors of exit access may be reduced as required during performances to a minimum of not less than one-fifth (1/5) foot-candle. (3) Ensure illumination is from a source of reasonably assured reliability such as public utility electric service. (4) Arrange illumination so that the failure of any single lighting component such as the failure of an electric bulb or the failure of one branch circuit will not leave any means of egress in darkness. (5) Where electricity is used as a source of illumination of means of egress, make the installation under provisions of NFPA 70, National Electrical Code. General Illumination: Ensure illumination levels in educational facilities conform to the IES lighting handbook latest edition. Design and circuit illumination so that the failure of any single lighting component such as an electric bulb or failure of one branch circuit will not leave any occupied area in darkness. (1) Classroom Lighting: (a) (b) Ensure the average initial illuminance level is not less than 60 RAW foot-candles. Base the average initial illuminance level on a light loss factor equal to the product of the ballast factor (BF) when multiplied by the voltage drop factor (VDF). Voltage drop is normally taken as 3 percent, therefore the voltage drop factor will be LLF = BF x VDF = BF x 0.97. All other factors shall be taken as one. Ensure the minimum RAW foot-candle illuminance level is not less than forty (40) footcandles. The maximum allowable rate of RAW foot-candle levels at task height within any 4 foot distance from one another shall be at a ratio of two to one (2:1). Provide a computer illuminance analysis printout for every typical classroom layout and special use areas. Consider surface reflectance as close as possible to actual and properly documented. Base the lamp lumen output on lamp manufacturer's published data.
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
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In specific cases, a full visibility analysis might be required in which case visual comfort probability and equivalent sphere illumination must be considered. (i) Classroom lighting fixtures shall be oriented perpendicular to the white board. (2) Chalkboard Lighting: Provide supplementary lighting for the chalkboard so the ratio of task background existence to chalkboard exitance does not exceed three to one (3:1). (3) Indirect Lighting Systems: Ensure the surface luminance (brightness) of any surface does not exceed 250 footlamberts. Ensure the uniformity ratio does not exceed five to one (5:1). (4) Parking Lot Lighting: Design the illuminance of the parking lot to provide a minimum of one (1) foot-candle at ground level with a maximum to minimum not to exceed twelve to one (12:1). Emergency Lighting: Provide emergency lighting where required by NFPA 101. In addition, provide emergency lighting in group toilets, electrical rooms, student occupied areas, mechanical rooms serving the EHPA shelter and the generator room. (1) When maintenance of illumination depends upon changing from one energy source to another, ensure that there are no appreciable interruption of illumination during the changeover. When emergency lighting is provided by a prime mover-operated electric generator, a delay of not more than ten (10) seconds shall be permitted. (2) Suitably illuminate every exit sign by a reliable light source. Continuously illuminate externally or internally illuminated signs whether in the normal or emergency power mode. (a) Externally Illuminated Signs: Illuminated by not less than five (5) foot-candles and employ a contrast ratio between letters and background of not less than one to two (1:2). (b) In an internally illuminated sign with translucent letters and an opaque background ensure the average luminance of the letters are a minimum of two (2) foot-lamberts and a maximum of three (3) foot-lamberts. Illuminate the letters such that the brightest spot is not more than four (4) times as bright as the darkest spot. (c) In an internally illuminated sign with translucent background and opaque letters, ensure the average luminance of the background is a minimum of three (3) foot-lamberts. Illuminate the background such that the brightest spot is not more than four (4) times as bright as the darkest spot. Ensure the contrast ratio between letters and background is at least one to two (1:2). (d) In an internally illuminated sign with translucent background and translucent letters, ensure the average luminance of the brighter portion is a minimum of six (6) foot-lamberts due to internal sources only. Illuminate the background such that the brightest spot is not more than four (4) times as bright as the darkest spot. Ensure the entrust ratio between letters and background is at least one to two (1:2). (e) DO NOT install self-luminous or phosphorescent exit signs in educational or ancillary facilities. (f) Ensure illumination of exit signs are at the required level for the emergency lighting of a minimum of 90 minutes. Illumination may decline to 60 percent of the required illumination level after 90 minutes. (g) Internally Illuminated Exit Signs: Illuminated by Light Emitting Diodes (L.E.D.'s) configured in such a way that failure of any one (1) single L.E.D. will not disrupt the continued illumination of the remaining L.E.D.'s. Single Face and Double Face Signs shall not consume more than 2 Watts. Ensure the rated average life of the sign is at least 30 years. The sign must be UL-924 listed. Conform to the following general illumination requirements:
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Classrooms Chalkboard lighting Laboratories
Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
Average FC (Maintained)
60 Provide exitance computer analysis 70
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Teaching Auditoriums (multiple systems) (*) Media Center Principal's and Assistant Principal's office Offices/ Clerical (*) Physical Education (Gym) (*) Cafeteria Interior Corridors Exterior Corridors Computer Laboratories (*) (* *) Covered Walkways and Connector Walks LEGEND:
30/70 70 70 60 30/50 range 50 30 10 30/50 range 5 FC
(*) Provide multiple level switching. (**) Indirect systems can be considered when ceiling is at 10'-6" minimum. Maximum of 250 footlamberts with a uniformity ratio of 4:1. e. Fluorescent Lamps and Ballast: (1) Lamps: T-8 (triphosphors) with minimum initial output of 2800 lumens, cool white GE Osram - Westinghouse. (2) Ballasts: Fully electronic integrated circuit. Total harmonic distortion - less than 12 percent THD, crest factor 1.4 or less, Magnatek - Universal - Advance - Motorola - Toshiba. f. Bottom of luminaires above finish floor, refer to SREF requirements. g. All Other Interior Areas: See IES Application Volume latest edition. Provide illuminance computer print out for all rooms/spaces under design. h. Parking Lot Lighting: (1) Minimum of one (1) maintained foot-candle with a max/min of 12/1 and not to exceed 0.05 watts/sq. ft. (2) Indicate Light Loss Factor: (a) Suggested MH Luminaires LLF = 0.75, HPS Luminaires LLF = 0.9 (b) SBBC reserves the right of actual performance verification. (c) Computer Analysis: Based of a 10 foot grid. i. Sport Fields: Discuss design criteria with SBBC Design Services Section prior to designing (IES RP-6). At a minimum two 4”C stub-outs in a pull box shall be provided from the closest electrical room with the capacity for the sports field lighting to the proposed location of the sports field. j. Provide emergency lighting requirements in all classrooms, public spaces and administration suites. k. Provide two (2) luminaires connected to emergency power in each classroom. Automatic switching of emergency luminaires will be allowed when luminaires are back to "ON" in the event of power failure. l. For Indoor Applications: Do not compute "Initial LLF" as "one" (1), but as the product of the "ballast factor" (BF) multiplied by the voltage drop factor (VDF) (minimum 0.97). m. The Florida Energy Conservation Manual lists an energy budget for school building interior lighting of 2.0 watts per square foot. If a lighting layout using more than 2.0 watts per square foot is selected, the engineer will be required to submit calculations to show that the entire building does not exceed the 2.0 watts per square foot for energy budget. n. Provide systems/power stub-outs terminated in a pull box to the proposed location of the future portables. The design shall take into consideration the power and system requirements of the portables
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and the electrical room where the power conduit originates shall have the capacity to serve the portables.
E. Lighting Control
1. Install lighting fixtures in instructional spaces so that the light level may be effectively reduced to facilitate the use of projected visual aids, allow note taking while the lights are dimmed or to allow the reduction of artificial illumination when natural illumination is provided. In schools with a generator, locate the emergency light switch by the entrance door and the normal light by the teacher’s desk. a. Multiple Switching b. Electronic Dimmers In order to conserve energy, provide one (1) motion detector in each classroom, custodial rooms and storage rooms. In science classrooms or other areas where gas is utilized, do not install motion detectors for light control. Chalkboards: In separate switch. Corridors: At contactor/time clock/energy management/custodial office. Outdoor: Photocell on/time clock off/power reserve/energy management. Group Toilet Light Fixtures: Controlled by a switch located in the custodian room. Dressing Room Light Fixtures: Do not provide incandescent makeup lights; instead provide full-spectrum fluorescent lights.
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F. Electrical Outlets
1. Provide four (4) or more duplex outlets in each instructional space. Consider the use of standard classroom equipment in locating these outlets throughout the space dedicated. Provide additional outlets where applicable for special equipment. Provide special purpose rooms with outlets suitable for the special equipment used. Place sufficient outlets and electrical circuits in strategic locations to serve the drop lights for localized task lighting. Ground all outlets. GFI outlets cannot be downstream protected. Provide all convenience outlets installed within 6 feet of water supplies, wet locations and toilet rooms with a ground fault circuit interrupt protection device (GFI). Where outdoor outlets are provided with direct grade level access they shall be weather proof outdoor GFI. Electrical Receptacles: DO NOT install within flammable or hazard storage rooms. Mechanical Rooms: Minimum of one (1). Connect all receptacles to GFI circuits. Gymnasiums: Minimum of three (3) per wall. Teacher's Lounge: Minimum of four(4). Offices: Minimum of one (1) per wall plus additional floor outlets to satisfy furniture layout. This does not include the computer receptacle.
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10. Secretarial Areas: Minimum of two (2) in each wall plus additional floor outlets to satisfy furniture layout. This does not include the computer receptacle. 11. Electrical Rooms: Minimum of one (1). 12. In accessible classrooms for pre-K through Grade 3, all electrical receptacles within reach of students shall have ground fault circuit interrupt protection devices (GFCI) except for the computer dedicated receptacles. 13. Branch circuits supplying data and printer’s workstations shall be dedicated to this use only. 14. Each phase conductor for computer circuits must have its own neutral.
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15. Lighting and power panels shall be provided with a minimum of 20 percent spare breakers and capacity, and a minimum of 20 percent spare capacity in all main panels and switchboards. 16. Do not provide electrical outlets in storage rooms.
G. Fire Alarm Systems
1. 2. 3. 4. 5. 6. 7. 8. 9. For existing facilities, the consultant shall discuss the re-use of the existing system or total replacement with the SBBC Design Services Section. The consultant shall visit the site and gather all proper information on the existing system. List this information on the design documents in the event of re-use. See the SBBC Design Services Section Specifications for Fire Alarm Addressable Systems, Section 13845. Provide buildings within 60 feet of each other with a common fire alarm. The SBBC goal is to have all existing hard wired systems replaced by new addressable systems. A dedicated zone module for future portable classrooms shall be provided. Upon activation of the fire alarm system, shut off gas supplied via solenoid valves including kitchen gas supply (except to the emergency generator). Reset: Not remote from solenoid valve. In fully fire sprinkled buildings, provide a smoke detector in custodial, storage rooms with electrical receptacles, and electrical rooms. Provide an explosion proof smoke detector in the flammable storage. Provide an audio/visual device in each classroom (horn/strobe).
10. Provide vandalproof smoke detectors in all group toilets. 11. Provide a Fire Alarm Visual Device (strobe) in every single toilet. 12. Provide fire alarm components complying with requirements for an EHPA in accordance with the most current SREF for schools with EHPA shelters. 13. On new construction when the building is provided with a sprinkler system, electrical rooms shall be 2-hour fire rated and provided with a smoke detector in accordance with the exception under NFPA 13. Communication Equipment Rooms (CER) and communication closets shall be provided with sprinkler heads. 14. For projects involving renovations, remodeling or additions, the consultant shall contact the SBBC District Maintenance Department Fire Alarm Supervisor at (954) 928-0200 regarding interface of the new fire alarm appliances with the existing fire alarm system. 15. Provide smoke detectors in dressing rooms. 16. Provide smoke detectors in classrooms with stoves. Devices shall not be located directly above the stove. 17. Do not provide horns/strobes on exterior of buildings. Use the program bells for recall purposes. 18. In schools without a fire sprinkler system, provide smoke detectors in rooms or spaces for storage, custodial closets, spaces under stages with wood structures and other unoccupied or unsupervised spaces. Mechanical Rooms shall be provided with heat detectors. Smoke and heat detector devices shall be installed in accordance with NFPA 72.
H. Master Clock and Intercommunication System
1. 2. 3. For existing facilities, the consultant shall discuss the re-use of the existing system or if the system will be totally replaced with the SBBC Design Services Section. The consultant shall visit the site and gather all proper information on the existing systems. List this information on the design documents in the event of re-use. For new facilities, the consultant shall adhere to the master clock and intercommunication system specifications issued by the SBBC.
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
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Please refer to standard wiring diagrams issued by the SBBC. In the shops, provide handsets for the intercom systems. In new facilities, provide ceiling speakers in the hallways connected to the intercom for all call purposes.
I. Instructional Television System
1. 2. 3. 4. Consultant: For existing facilities, the consultant shall discuss whether to re-use the existing antenna mast and head end or total replacement with the SBBC Design Services Section. If in an existing facility, the decision is made to replace the existing antenna tower and head-end, refer to the SBBC Standard Details and specifications. For new facilities, refer to the SBBC Standard Details provided by the SBBC. BECON ITV shall perform signal test probing to determine the size and location of the pole. The BECON test report shall be generated prior to the completion of the Phase III 50% construction documents and the consultant shall use this information to prepare the drawings. This report shall clarify dish size/configuration and any other equipment that would normally be variable based on proposed pole location. The Contractor shall supply shop drawings for approval by BECON of the complete system showing all duct banks and electrical room tie points and device locations as well as devices used, and cable sweep test certification. Without this approval by BECON, the installation of the system shall not progress to the next phase of construction. BECON reserves the right to perform periodic inspections during installation of the MATV system. Final inspection shall be approved and signed off by BECON. The consultant shall adhere to the SBBC specifications for ITVas provided by the SBBC. Telephone Distribution System: The consultant shall coordinate with the SBBC Design Services Section and Southern Bell for the expandability of the existing system. For new facilities, it is the consultant's responsibility to coordinate the telephone service with Southern Bell.
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10. Provide pull string in each empty raceway.
J. Security System
1. 2. The consultant shall discuss the criteria with the SBBC Design Services Section prior to commencing work. Provide pull string in each empty raceway.
K. Energy Management System
1. Provide an empty conduit system from the main EM/S to each mechanical room containing air handler unit (AHU’s) and an automatic interlock for ON/OFF operation.
L. Special Systems
1. Provide the following special systems: Coordinate with the SBBC Design Services Section for the standard specifications for all systems listed below. a. Gymnasium Sound System. b. Gymnasium Score Board. c. Auditorium Stage Lighting System/Sound System. d. Music Rooms Intercom. e. Stage (Platform) Intercom System. f. Stage (Platform) Sound System.
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
M. Special Considerations
1. Dry Type Transformers: a. Ensure transformers are energy efficient per SREF requirements. b. Provide transformers with the following temperature rating: (1) Less than and Including 9 KVA - 115 Degree C. (2) Above 9 KVA - 80 Degree C. c. Provide vibration pads for all transformers. d. Provide a disconnect on the primary side of the transformer when the source of power is not within sight. Electrical Motors: a. Ensure motors are energy efficient. b. Provide motors with a minimum power factor of 0.85 at 100 percent load. c. Motor Efficiency: Comply with IEEE Test Procedure 112, Method B. d. Provide motors with a Motor Saver Catalog No. 455 as manufactured by Sym Com, Inc. Emergency Generators: a. Emergency generators sized 100 KW or less shall be LPG engine driven. Emergency generators sized over 100 KW shall be diesel engine driven. b. Provide a cost comparison analysis for the use of LPG vs. diesel fuel. Address and comply with EPA and DPEP environmental requirements. Emergency Power: Types of emergency backup power shall not be mixed on any one campus. Backup emergency power shall be provided by any one of the following: a. Rechargeable central storage battery system. b. Generator-Supplied automatic transfer switch. c. Non-Interruptible power supply with integral automatic transfer mechanism. d. Exception: “Unit equipment” type emergency lighting devices in accordance with NEC Article 700-12 will satisfy the requirement for initial and backup emergency power to emergency lighting equipment and exit signs only when connected to the very same branch lighting circuit that serves the general illumination in that room in which the “unit equipment” fixture is mounted. Cord and plugs are not allowed. Each area being used as the EHPA shelter shall be provided with a duplex receptacle connected to the generator with a red cover plate to allow for the connection of a portable TV. The EHPA Manager’s Office shall be provided with a dedicated telephone line. In the case of a Special Needs EHPA shelter, two dedicated telephone lines shall be provided in the manager’s office. Luminaires: a. Provide all luminaires above 20 Watts with a minimum of 0.85 power factor. b. Base all classroom lighting layout on an illuminance computerized analysis for evaluation. Control Panels for HVAC Equipment: a. Ensure all panels are "UL" labeled or listed. This requirement includes all air conditioning control panels and energy management control panels as well. Electric Panels: a. No half (1/2) size or tandem breakers allowed. b. When main breaker is required, ensure it is not of the feedback type.
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
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Electrical Panels: DO NOT install panels in classrooms, corridors or in storage rooms. Provide electrical rooms for the installation of the electrical panels. Provide surge protection in all panels. Electrical panels shall be properly labeled and circuits shall be identified as to use by typewritten directories installed inside the panel door. Voltage drops for NEC 215-2 shall be calculated using Note 2 of Table 9 of the NEC and shall not exceed three percent of the nominal line voltage.
10. Wiring: a. Provide a grounding conductor in each wiring raceway (conduit, EMT, PVC, etc.). b. Ensure all conductors are stranded copper. 11. Raceways: Ensure all conduits in the cells of a blockwall are rigid galvanized conduit. Minimum conduit size shall be 3/4 inch. 12. Site Visitation: a. The consultant shall coordinate with the SBBC Design Services Section in order to conduct the field inspection. He shall be assisted by an electrician from the SBBC District Maintenance Department for the opening and field data gathering of the electrical panels, devices, etc. 13. For the AS400 equipment, provide a quad of 120V outlets for the monitor, modem and printer. This circuit shall be dedicated and on the UPS. There is an AS400 terminal that will reside on the DPC’s desk and requires 120V on the building UPS. The AS400 requires a single dedicated receptacle type NEMA 6-15R connected to the UPS on a one branch circuit 208/240V, 1 Phase, 15 Amp, 3 wire (two hot and ground). 14. Facilities provided with elevator and an emergency generator shall have the elevator connected to the generator wherever possible. The elevator shall be provided with a dedicated telephone circuit which rings to a 24 hour emergency service. 15. The cable tray, if applicable, shall be for the sole use of the Telecommunications and Energy Management Department (EM and Security). The HVAC equipment control wiring not installed in the cable tray shall be installed in a separate conduit. 16. In EHPA shelters, the main fire alarm panel shall be located in the shelter manager’s office and a fire alarm remote annunciator panel, with the characteristics as listed in the SBBC Specification Section 13848 – Fire Alarm, shall be located in the school’s main administration office. 17. For new or replacement Bell South entrance facilities, the consultant shall be required to provide to the Facilities Telecommunications Coordinator one 30”x42” copy of the Civil Site Survey and the electrical drawing sheet showing the demarcation room where the cable will be terminated. The Facilities Telecommunications Coordinator will coordinate with Bell South. 18. Systems (fire alarm, intercom, clock, security) panels shall be located in the electrical rooms. Communications closets are dedicated to communication equipment only. 19. PVC conduit is allowed to be used when embedded in the concrete of the tiltup wall construction with a minimum cover of 2 inches concrete only when the facility is fully fire sprinkled.
N. Exhaust Fans
1. Ensure all general exhaust fans in toilets and in non-classroom areas such as gymnasiums, auditoriums, etc. are started and stopped by a single zone switch on the central H.O.A. Control Panel already dedicated to close the outside air damper of the air handler unit serving that zone. Continuously exhaust these areas during occupied periods and shut down during evenings, weekends and holidays when the building is unoccupied. Design all exhaust fans, with the exception of the kitchen hood exhaust fan, to immediately shut down upon activation of the building fire alarm system.
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
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All custodian room exhaust fans shall be electrically interlocked to the associated air handler unit serving that zone. Only as a last resort and approval by the SBBC Design Services Section shall the fan be equipped with a time-delay switch so that the fan continues to operate for a minimum of five minutes after the light has been turned off. Provide the Science Material Storage/Preparation Area Organic and Inorganic Storage Rooms with continuous operating, explosion-proof exhaust fans coated with a chemical resistant coating. The same applies to the Flammable Storage Room with the exclusion of the chemical resistant coating. An audible alarm activated by a pressure differential switch in the exhaust ductwork shall be provided to indicate fan failure. The Dust Collector shall operate only when the starter is activated in the "ON" position. The dust collector shall be electrically connected to the zone AHU so that shutting down the AHU by the fire alarm system shall also shutdown the dust collector. The kiln room exhaust fan shall operate when the local control starter is in the 'ON' position. A local firestat shall shutoff the fan in the event of a fire. Ensure that the fan is not interlocked with the air handling unit. Exhaust fan is to be interconnected with the kiln operation. Ensure that the kitchen waterwash exhaust hood is independent of the kitchen air conditioning system. The Spray Booth Compressor shall be interlocked with the exhaust fan.
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O. Emergency Cutoff Switch
1. Provide every laboratory space that has electrical receptacles at student workstations, with an emergency cutoff switch key reset within 15 feet of the instructor's workstation. Ensure that the emergency cutoff switch is operable by a single motion and interrupts power to all student workstations. Provide every shop space which has power operated machinery accessible to students with at least two emergency cutoff switches which shuts off power to student accessible machines and receptacles in the shop. Locate one emergency cutoff switch near the machinery and one in the instructor's office if there is a clear view of the entire shop area. Ensure the emergency disconnect switch is operable by a single motion. In addition, all equipment in the shop space shall be provided with electro magnetic starters controlled by a Start/Stop station. EXCEPTION: Non-hazardous machines not requiring emergency cutoff includes office machines, computers, sewing machines and potter's wheels. 3. Provide a "Panic" switch inside the sauna and steam room, two (2). Tie the panic switch into an alarm or other approved warning device in a supervised space inside the sauna and/or steam room. Label the operation of the switch to indicate the intended function. Ensure the backup power supply for NEC Article 700 emergency systems are storage batteries per NEC 700-12(a) or an on-site engine driven emergency generator per NEC 700-12(b) or uninterruptible power supply per NEC 700-12(c). When an on-site engine driven generator is used to serve emergency circuit in several buildings, install only one (1) automatic transfer switch. Unit equipment in accordance with NEC 700-12(f) is permitted for emergency illumination in NEC 700-16, only if all emergency equipment is battery backup powered.
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P. Energy Management/Security (EM/S) System
1. The SBBC Educational Technology Services Department has an on-going project to install an integrated energy management and security (EM/S) at every school site. The EM/S system consists of Andover Controls Corp. based equipment which starts and stops the HVAC equipment and optimizes the outside
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Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
lighting. In addition, the system interfaces to the electronic security devices which report intrusion alarms to a central monitoring station. 2. The Central H.O.A. Control Panel shall be located in the Media Center Communications Equipment Room (CER). A 36 inch x 24 inch EM/S panel shall be mounted adjacent to Central H.O.A. Control Panel so an open wall space will be required. In existing schools requiring renvation, the new HVAC systems shall be wired back to the exisating Central H.O.A. Control Panel. A simplified sequence of operation geared to a non-technical individual explaining the HVAC system operation shall be installed behind a Plexiglass or Lexan cover adjacent to the Central H.O.A. Control Panel. An electrical schematic drawing of the equipment shall also be provided in a similar manner for use by SBBC repairmen during servicing of the equipment. Ensure all AHU's, chilled water and condenser water pumps, general exhaust fans, toilet exhaust fans and outside air dampers are started and stopped by zone from a Central H.O.A. Control Panel. Should the installed automatic temperature controls (ATC) be manufactured by Johnson Controls (approved for building additions only), the panel shall be provided with separate, face mounted Hand-Off-Auto (H.O.A.) switches, zone status pilot lights and permanent engraved labels for each zone. In most cases, the ATC shall be as manufactured by Andover Controls Corp. and the front panel shall be blank since the above functions shall be controlled by a desktop computer at the facility and at the TSS Building located offsite. Each zone should not exceed a total of 20 HP connect fan motor load. The mechanical room outdoor air dampers and toilet exhaust fans shall be on one zone and separate from the AHU’s. The HVAC equipment is to be enabled and disabled by a single zone switch. All electrical wiring interface between the SBBC EM/S system and the HVAC system will be done at the auto side of the H.O.A. switch for Start/Stop control. Electrical Requirements: Without having a specific building design, it's nearly impossible to specify conduit layouts. The basic idea is to provide a 1-inch conduit from each electric room, home run to the Custodian's Office. Install a 120 VAC quad outlet for the security power supply in each electrical room. During the Phase plan review, contact the SBBC designated EM/S representative, Telephone #765-6496, for site specific conduit layout requirements and additional information concerning the EM/S interface and ATC requirements.
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Q. Communications Infrastructure
1. 2. Refer to Technical Specifications (Computer Networking, and Computer Networking Electrical). Refer to SBBC Communication Networking Design Layout Documents.
R. Details
1. Refer to the installation details as prepared by SBBC Design Services Section.
S. General Comments
1. Standard SBBC electrical details to assist the consultant on the execution of his work are available from the SBBC Facilities and Construction Management Department, Design Services Section.
Design Considerations and Criteria The School Board of Broward County, Florida Issue Date June 5, 2003
Electrical Design Criteria Page 12 of 12