SECTION 33 70 00 - ELECTRICAL DISTRIBUTION PACKAGED GENERATOR ASSEMBLIES Generator Fire Safety: Generator assemblies should be located outside the building. All fuel piping from the outside of the building for day tank filling and venting shall be hard piped. A high liquid level device shall be provided for day tank overflow protection. A generator fuel system shall be arranged to automatically shut down upon a fire, detected leak or high day tank level. Consult with Facilities Management- Environmental Services for information on generator operating permits and Spill Prevention Control and Countermeasures (SPCC). All generator sets shall be located to disperse exhaust fumes, vibration and noise without affecting the normal functions of the building and surrounding site. On-site fuel source shall provide for a minimum of 48 hours of run time. Diesel Engine-Generators are preferred. Other fuel types shall be evaluated on an individual project basis. All generators shall have an automatic transfer switch. Provide startup services and training for Owner s personnel by a factory certified service representative. Minimum training time shall be 4 hours. Reactive Load Bank test is required, minimum 4 hours with 2 hours at 100%, 0.8pf. Acceptable Manufacturers Caterpillar, Cummins or Kohler; a factory authorized service center must be located within 100 mile radius of the University of South Alabama. The generator fuel system should be arranged to automatically shut down upon a fire, detected leak or high day tank level. BATTERY EQUIPMENT Sealed batteries shall be used for emergency lighting systems when an emergency generator is not available. Provide adequate ventilation and cooling of battery rooms and battery cabinets to maintain full life expectancy. Batteries on racks or in cabinets shall be accessible for maintenance. Vertical access above batteries shall be a minimum of 6 inches. UPDATED NOVEMBER 17, 2017 Page 1 of 8
TRANSFER SWITCHES All transfer switches shall be automatic and rated Service Entrance with 100% Main Breaker when serving entire building. Provide a minimum of two sets of auxiliary form C contacts for normal and emergency transfer switch positions. TRANSIENT VOLTAGE SUPPRESSION Some users may require transient voltage surge suppression. The Design Professional shall review options with the user to determine specific needs. When suppression equipment protects an entire panelboard, locate this equipment inside the panelboard enclosure. Provide a disconnecting means to isolate the suppression equipment for repair and replacement. LOW VOLTAGE CONDUCTORS Aluminum conductors are prohibited. The minimum wire size for lighting and power branch circuits is #12 AWG. The minimum wire size for Class 1 control circuits is #14 AWG. Any conductors installed in flexible conduit at terminal connections of rotating, vibrating or moveable equipment shall be of stranded wire. Normal, emergency, life safety, 120/208, and 277/480 shall not occupy the same raceways. Neutral conductor capacity shall be increased as necessary for harmonics. Provide dedicated neutrals (one per phase with phase color tracer). GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS All grounding system conductors shall be copper. Provide a grounding conductor with all circuits. SECONDARY CIRCUITS Color code secondary service, feeder, and branch circuit conductors with factory applied color as follows: 208/120 Volts Phase 480/277 Volts Black A Brown Red B Orange Blue C Yellow White Neutral White or Gray (with tracer for each associated phase) Green Ground Green UPDATED NOVEMBER 17, 2017 Page 2 of 8
SERVICE ENTRANCE At the points where conduit penetrates concrete that is in contact with soil, that conduit shall be Schedule 40 PVC conduit bedded in sand; transition to rigid elbows with asphaltum paint (two coats) for turning up into equipment. SWITCHBOARDS Phase, neutral and ground bus shall be copper. The phase arrangement on three phase bus shall be A-B-C from left to right, top to bottom, front to back as viewed from the front of the switchboard. Provide a minimum 20% spare, usable space in new switchboards for future increases in electrical requirements. Provide continuous ground bus the full length of the switchboard. In existing buildings, new switchboards shall match existing switchboards. Acceptable Manufacturers: General Electric Cutler-Hammer Siemens PANELBOARDS Provide 5-1 spare conduit stubs from flush mounted panels into suspended ceiling space or other accessible space. Provide a minimum 20% spare circuit space and 20% spare capacity in new panelboards. Phase, neutral and ground bus shall be copper. All panelboards shall have separate neutral and grounding busses. All grounding and neutral wiring shall be terminated on the proper bus. In existing buildings, new panelboards shall match existing panelboards. Provide each panel with a clear, plastic covered, typed circuit schedule. The schedule shall identify circuits by room number and location in room using final room numbers provided by the Owner. Provide a nameplate on the inside of the panelboard door with panel ID, voltage & phase, and power origin. Circuit breakers on branch circuit panelboards shall be bolt-on type. Covers to consist of full-length hinge (door within a door). Acceptable Manufacturers: UPDATED NOVEMBER 17, 2017 Page 3 of 8
General Electric Cutler-Hammer Siemens MOTOR CONTROL CENTERS Starters shall have circuit breakers, H-O-A, RED RUN GREEN-STOP LEDs and control power fuses. Control circuit voltage shall be 120 volts or less. Provide a minimum of two auxiliary contacts (1 N.O. and 1 N.C.) in magnetic starters in addition to what is being used. Design each motor control center section so starter units may be rearranged, removed or added. Provide a minimum 20% spare, usable space in each new motor control center. In existing buildings, new motor control centers shall match existing motor control centers. Acceptable Manufacturers: FUSES General Electric Cutler-Hammer Siemens Renewable fuses shall not be used. As much as possible, equipment should be specified with fuse holders that shall accept fuses dimensionally the same as Class H fuses. Each project shall supply one set of three spare fuses for each type and size fuse installed. SAFETY SWITCHES AND CIRCUIT BREAKERS Safety switches shall be heavy duty. To provide an immediate and observable point of electrical disconnect, locate a disconnect switch near each piece of fixed electrical equipment. Tandem branch circuit breakers are prohibited. Circuit breakers in branch circuit panelboards shall be bolt-on type. In existing buildings, new enclosed switches and circuit breakers shall match existing enclosed switches and circuit breakers. UPDATED NOVEMBER 17, 2017 Page 4 of 8
All safety switches shall have a durable label permanently attached to the inside of the cover describing the fuse size, type, current limiting ability and devices controlled. All safety switches intended for use on circuits where current limiting fuses are required shall be specified with rejection clips designed to permit installation of Class R fuses only. Covers on safety switches shall be provided with a method of opening the cover without opening the switch. All safety switches shall have a grounding bar and nameplate attached with screws. Safety switches in mechanical rooms shall have NEMA 3R enclosures unless the environment or usage requires a more restrictive enclosure; outdoor and wet locations shall be NEMA 4X. Acceptable Manufacturers: General Electric Cutler-Hammer Siemens ADJUSTABLE SPEED DRIVES (ASD) VARIABLE FREQUENCY DRIVES (VFD) The design shall address the effects of VFD input current harmonics on the distribution system. Specify harmonic criteria and require field testing of harmonic performance where appropriate. Manufacturer shall provide harmonic analysis of the supplied VFD, total harmonics are not to exceed 3%. Provide VFD s that are compatible with the motors they control. Provide bypass switching capability when back-up equipment is not provided. Provide three (3) contactor bypass switching capability when back-up equipment is not provided. A variable frequency motor controller shall not serve more than one piece of equipment. In existing buildings, new variable frequency motor controllers shall match existing variable frequency motor controllers. Provide startup services for the Owner s personnel by a factory certified service representative. Minimum training time shall be 4 hours. Where motors are 40 HP and larger, VFD shall be 480 volts with step up transformers as required. Where we are not trying to maintain consistency with existing ASDs, acceptable manufacturers are: ABB Eaton Allen Bradley Drives shall include manual bypass of the VFD for the following: 480 volt drives 125 HP and larger UPDATED NOVEMBER 17, 2017 Page 5 of 8
208 volt drives 60 HP and larger Critical applications Drive Isolation Transformer (where required for changing voltage): General: Factory assembled and tested, air cooled dry type transformer, having characteristics and ratings as indicated. Units shall be designed for 60 Hz service. Transformer shall be a threephase, Delta Wye, or Delta-Delta unit. Grounding: The transformer shall operate with an ungrounded delta primary and a grounded wye secondary, or a corner grounded Delta secondary. Core: Grain Oriented, non-aging silicon steel. Coils: continuous windings with no splices except for taps. Insulation System: UL recognized 220ºC. Performance shall be obtained without exceeding 150ºC temperature rise while operating in 30ºC ambient (24 hour average). Enclosure: Constructed of heavy gauge steel with electrostatic applied finish. Enclosure shall be ventilated, drip-proof with lifting holes. Sound levels shall not exceed 55 db. Non-linear rating: Harmonic rating shall be equal to or greater than the harmonic distortion produced by the supplied VFD, as determined by the harmonic analysis supplied by the VFD manufacturer. IDENTIFICATION All switching, protective devices and metering on main distribution panels shall be identified with labels. Labels shall be adhesive backed vinyl or plastic with ½ inch letters. Identification labels are required for all distribution equipment from the service through branch circuit panelboards and motor control centers. The Design Professional shall specify the wording of identification labels. Label all receptacles on the cover plate with self-adhesive labels. Label shall indicate panel name and circuit number. All light fixtures shall be labeled with the panel number and circuit number from which they are fed. Place label out of public view. Coordinate label location with the Owner. All junction box covers shall be labeled with the panel number and circuit numbers contained in the junction box. Exposed boxes in finished areas: label on inside of cover. Exposed boxes in unfinished areas: label on outside of cover. UPDATED NOVEMBER 17, 2017 Page 6 of 8
Concealed boxes above accessible ceilings: label on outside of cover. FEEDERS All feeders shall have a separate copper grounding conductor installed. In no case shall the conduit or raceway be used as the grounding conductor. All conduit sizes and conductor numbers and sizes shall be shown on the drawings. All panelboards shall have separate grounding and neutral busses. All grounding and neutral wiring shall be terminated on the proper buss. No snap-in breakers shall be allowed. Bolt-in type breakers shall be used. I-Line and GE Spectra Series are acceptable. BRANCH CIRCUITS All wiring systems shall be installed using conduit. Flexible wiring systems shall not be used. A separate grounding conductor shall be installed. Use of the conduit or raceway is not an acceptable grounding method. All general purpose power circuits shall be a minimum of 20 amps. No piggyback breakers shall be allowed. No power circuits shall have shared neutrals. CONDUIT AND BOXES Conduit shall be supported from the building structure. Attachment to other pipes, conduits, ductwork, etc. shall not be allowed. Non-metallic conduit or boxes shall not be used except in wet locations. In cases where it is used, conduit 2 and smaller shall be a minimum of Schedule 40. Conductors carrying more than 150v to ground shall not be installed in conduits with conductors carrying less than 150v to ground. Schedule 80 PVC conduit shall be utilized anywhere conduit emerges from concrete or where conduit may receive physical abuse. EMT shall not be used outdoors, in wet locations, in floor crawl spaces, or below 5 AFF. For Branch Circuits, the minimum conduit size shall be 3/4. For Feeders, conduit is to be sized at least one size above the NEC requirement of wire being installed or anticipated to be installed, with minimum size of 1. PVC conduit shall be used for underground electric circuits less than 600 volts that are: Under paved areas and areas scheduled to be paved. UPDATED NOVEMBER 17, 2017 Page 7 of 8
Next to permanent buildings, under formal planting beds and in extremely high areas that would be difficult to excavate due to regular heavy use. All other applications shall be direct bury. A red plastic tracer tape is to be buried 18 above the cable or conduit in all installations. PVC conduit for Blue Cap phones and parking gates shall be sized a minimum of 1. PVC conduit shall be Schedule 40 minimum weight and to be designed for electric application with all connections solvent welded. All metallic fittings shall be compression type rated for ground connection. Thin wall indenter fittings are prohibited. All fittings shall be galvanized steel or malleable iron. The use of flexible metal conduit shall be limited to recessed lighting fixtures. Six foot length maximum. Liquid Tight flexible metal conduit shall be used to connect transformers, rotating, vibrating or moveable equipment. Empty conduits shall have nylon pull cords installed with temporary caps or plugs. Raceways, boxes and their supports shall be compatible with the atmosphere of the area in which they are installed. To reduce sound transmission, wall outlet boxes shall not be installed back-to-back in partitions. UPDATED NOVEMBER 17, 2017 Page 8 of 8