1、 ATIS-0600311.2007 DC POWER SYSTEMS TELECOMMUNICATIONS ENVIRONMENT PROTECTION AMERICAN NATIONAL STANDARD FOR TELECOMMUNICATIONS The Alliance for Telecommunication Industry Solutions (ATIS) is a technical planning and standards development organization that is committed to rapidly developing and prom
2、oting technical and operations standards for the communications and related information technologies industry worldwide using a pragmatic, flexible and open approach. Over 1,100 participants from over 300 communications companies are active in ATIS 22 industry committees and its Incubator Solutions
3、Program. AMERICAN NATIONAL STANDARD Approval of an American National Standard requires review by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standa
4、rds Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made towards t
5、heir resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standar
6、ds. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the America
7、n National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Stand
8、ards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Notice of Disclaimer 2. Battery string;
9、 3. Charge bus; 4. Discharge bus; 5. Primary power distribution; and 6. Secondary power distribution. 5.3 Rectifier/Chargers Rectifier/chargers functionally convert ac input power to regulated dc output power. Normally two or more rectifier/chargers are provided with their dc outputs connected in pa
10、rallel to a common power bus. 5.4 Charge Bus The charge bus shall be designed and installed so that equipment is accessible for installation or removal while the bus is electrically hot. Insulated conductors, when used for the charge bus, should be run directly between rectifier/charger output and a
11、 terminal plate at the battery terminals, or terminate at a rigid splice plate at one or both ends - i.e., at the rectifier/charger(s) output and battery terminals. 5.5 Battery string A battery string is a group of electro-chemical cells connected in series by intercell connectors. More than one bat
12、tery string may be provided in parallel to increase the energy storage capacity. 5.6 Discharge bus The charge bus (see 5.4) and the discharge bus may be combined as one and the same. Insulated conductors, when used for the discharge bus, may run directly between the battery terminals and the primary
13、 distribution network, or terminate at a rigid splice plate at one or both ends - i.e., at the battery terminals and at the distribution. ATIS-0600311.2007 7 Figure 1 - Typical DC Power System ATIS-0600311.2007 8 5.7 Primary distribution Primary distribution is the portion that includes the first ov
14、ercurrent protection devices downstream from the discharge bus as shown in Figure 1. The primary distribution system contains a powerboard that houses the overcurrent protection devices and the downstream power distribution network that feeds the secondary distribution. In some instances, the primar
15、y distribution serves the load equipment directly, eliminating the secondary distribution. Primary distribution powerboards shall meet the requirements of 7.8.4. Overcurrent protection devices shall be either fuses or circuit breakers that meet the requirements of 7.3 and 7.4. They are selected to p
16、rotect conductors. 5.8 Secondary distribution Secondary distribution is an intermediate protection network between the primary distribution and the load equipment, as shown in Figure 1. The secondary distribution network contains a powerboard that houses the overcurrent protection devices, and the d
17、ownstream power conductors to the load equipment. Secondary distribution may be located adjacent to the primary distribution powerboard or remotely on the same or different floors. Secondary distribution powerboards shall meet the requirements of 7.8.4. Overcurrent protection devices shall be either
18、 fuses or circuit breakers that meet the requirements of 7.3 and 7.4. They are selected to protect conductors. 6 GROUNDING or they shall be permanently identified with a green or green/yellow marking as a grounding conductor at the terminations. An insulated conductor in a multiconductor cable used
19、as a grounding or bonding conductor shall be permanently identified as above. 8.8 Circuit disconnects 8.8.1 Disconnect requirement This standard shall not require any circuit-disconnect devices between the battery and charger/rectifiers or between the battery and the input to the primary distributio
20、n. If an overcurrent-protection device is used in the distribution, a circuit disconnect shall be required. Third-party certified overcurrent protection devices or fuseholders, certified as disconnect devices, may be used. ATIS-0600311.2007 15 8.8.2 Return conductors Return conductors may have a dis
21、connecting device connected in series, provided that the device is a multiple-pole device synchronized to break all conductors of the circuit when operated. 8.8.3 Grounding conductors No disconnect device shall be connected in series with any frame or equipment grounding conductor. 8.9 Guarding 8.9.
22、1 Physical damage prevention Where there is a possibility of unintentional physical damage to equipment or conductors, guards or enclosures shall be provided. 8.9.2 Rigid uninsulated bus When a rigid uninsulated power bus is located adjacent to or in the immediate path of normal or emergency exits,
23、the exposed conductive parts shall be insulated or guarded against contact. 8.9.3 Live parts (160-volt-dc class) Live parts shall be marked or guarded against unintentional contact if at a height of less than 7 feet above the floor. 8.10 Clearances and working space 8.10.1 Conductive part spacings T
24、he distance between bare conductive parts shall not be less than that shown in Table 2. Spacing at third-party certified switches, fuseholders, or circuit breakers, and the spacings in third-party certified equipment and components shall be exempt from these minimum spacing requirements. 8.10.2 Fiel
25、d wiring terminals Field wiring terminals shall meet the clearance spaces given in Table 2. 8.11 Overcurrent protection Primary- and secondary-distribution circuits shall be protected by overcurrent protection devices having a rating or setting proper for the application. Charge and discharge circui
26、ts shall not require overcurrent protection. These circuit conductors, when not provided with overcurrent protection, shall be routed separately from overcurrent protected conductors. ATIS-0600311.2007 16 8.11.1 Scope This subclause of the standard provides the general requirements for overcurrent p
27、rotection of primary- and secondary-distribution circuits of not more than 160 volts dc. Overcurrent protection for conductors is provided to open the circuit if the current reaches a value that will cause excessive or dangerous temperatures in conductors or conductor insulation. 8.11.2 Location in
28、circuit An overcurrent device, when required, shall be connected at the point where the conductor to be protected receives its supply. 8.11.3 Readily accessible Overcurrent devices shall be readily accessible. 8.11.4 Not exposed to physical damage Overcurrent devices shall be located where they will
29、 not be exposed to physical damage. 8.11.5 Frame internal overcurrent protection Where overcurrent protection is used for equipment or components internal to an equipment frame, it shall not be used as a substitute for primary- or secondary-distribution circuit protection. 8.11.6 Remote sense leads
30、Ungrounded remote sense leads from each rectifier/charger shall be protected against overcurrent or short-circuit faults. Overcurrent protection devices or current limiting circuits shall be acceptable methods for protecting these leads. 9 WIRING METHODS 9.1 Conductor ampacity and size Ampacities of
31、 conductors and the insulation type required for suitability shall be as referenced in Tables 3 and 4. The ampacity of rigid bus conductors is given in Table 5. 9.2 Conductors of different systems Power conductors of alternating current or direct current shall be permitted to occupy the same wiring
32、enclosure or cable rack, provided all conductors have an insulation voltage rating equal to the maximum circuit voltage rating of any conductor within the enclosure or cable rack. See 9.7.3. ATIS-0600311.2007 17 9.3 Wiring in ducts, plenums, raised floors, and suspended ceilings 9.3.1 Ducts and plen
33、ums No conductors shall be located in ducts or plenums used for the transfer of dust, loose stock, or flammable vapors. 9.3.2 Raised floors and suspended ceilings non air handling spaces Spaces below raised floors and above suspended ceilings, when not used for air handling, shall be permitted to co
34、ntain all insulated wiring systems described herein. The only uninsulated conductor permitted shall be the grounding conductor. 9.3.3 Raised floors and suspended ceilings air handling spaces (To be determined.) 9.4 Bends The bend radii of field-installed conductors shall be sufficiently large to ens
35、ure that no damage is done to the insulation or the conductor. The minimum-bend radius for coarse concentric-lay stranded insulated cable shall be as listed in Table 6. The cable-bend radius shall be measured on the inside bend. 9.5 Conductors for general wiring 9.5.1 Scope The following paragraphs
36、provide general guidelines in the inspection of field-installed conductors used in dc power systems. Topics addressed include conductor type, ampacity, and environment. 9.5.2 Conductors Conductors (individually insulated wire, or rigid bus bars) shall be aluminum, copper-clad aluminum, or copper. Co
37、nductors, and their installations, shall be suitable for the condition of the location, including moisture, corrosion, ambient temperature, and mechanical protection factors. All conductors shall be supported such that excessive pressure is not transmitted to the electrical termination of the conduc
38、tor. Spacings of conductors shall be such that the operating temperature of each conductor shall not exceed its designated limit. Open wiring of conductors shall be acceptable, provided the conductors are protected from mechanical injury. The terminations of conductors shall be made by acceptable wi
39、re connectors for that particular conductor as evaluated in its own environment. Crimp-type (irreversible compression-type) terminations shall be made using third-party certified crimping devices. 9.5.3 Stranded conductors Termination of stranded conductors shall be with approved wire connectors suc
40、h that all strands are contained within the connector openings. ATIS-0600311.2007 18 9.5.4 Bus conductors Spacing of bus bars shall be such that the operating temperature of each conductor shall not exceed its designated limit. 9.5.5 Conductors in parallel When conductors are electrically joined to
41、form the equivalent of a single conductor, the following conditions shall be met: Cables shall be the same length. Cables shall be made of the same conductive material and have the same cross-sectional area. Cables shall use the same insulation type. Cables shall all be terminated in the same manner
42、;. Conductors shall be next to, or as close to each other as possible. 9.5.6 Bus duct Bus duct shall be defined as a grounded metal enclosure containing factory-mounted rigid bar conductors. The installation and sizing of the bus duct shall be in accordance with the manufacturers guidelines with reg
43、ard to temperature and environment. 9.5.7 Cable bus Cable bus shall be defined as an approved assembly of insulated conductors with fittings and conductor terminations in a completely enclosed metal housing. Installation and sizing of conductors shall be within the manufacturers ratings. 9.6 Cable r
44、ack 9.6.1 Scope A cable rack system shall be defined as a unit or assembly of units or sections and associated fittings forming a rigid structural system used to support cables. 9.6.2 Cables permitted Approved single-conductor and factory-assembled, multiconductor-control, signal or power cables sha
45、ll be permitted, and may be installed in common cable rack systems. See 9.7.3. 9.6.3 Locations not permitted Cable rack systems shall not be used in hoistways or where exposed to severe physical damage. 9.6.4 Construction Cable racks shall have strength and rigidity to provide support for all contai
46、ned wiring. These rack systems shall be free of sharp edges, burrs, or projections that could damage the conductor insulation; ATIS-0600311.2007 19 and shall be made of a corrosion-resistant material or shall be protected against corrosion. All systems shall have means to contain the conductors and
47、include fittings or other approved means for changes in directions and elevation of runs. 9.6.5 Installation Cable rack systems shall be installed as a complete system where each run of cable rack is completed before the installation of cables. The system shall be designed to minimize stress to the
48、conductors as they enter from an enclosure or other cable rack. 9.6.6 Partitions and walls Cable racks shall be permitted to pass through walls and floors where the installation, including all cables, shall not substantially increase the spread of fire. To accomplish this, openings through which cab
49、le racks penetrate fire-resistant walls and floors, shall be firestopped using approved methods. Cable racks shall be accessible with space provided to install and maintain the cables. 9.7 Cable installation 9.7.1 Cable splices Crimp-type (irreversible compression-type) splices and taps shall be permitted within cable racks. Non-crimp splices and taps are permitted, provided they are accessible. 9.7.2 Securing All power cables shall be supported and secured both vertically and horizontally. Securing systems shall suppor
