1、UFC 3-510-01 1 MARCH 2005 Change 2 22 September 2009 UNIFIED FACILITIES CRITERIA (UFC) FOREIGN VOLTAGES AND FREQUENCIES GUIDE APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-UFC 3-510-01 1 MARCH 200
2、5 Change 2 22 September 2009 UNIFIED FACILITIES CRITERIA (UFC) DESIGN: FOREIGN VOLTAGES AND FREQUENCIES GUIDE Any copyrighted material included in this UFC is identified at its point of use. Use of the copyrighted material apart from this UFC must have the permission of the copyright holder. U.S. AR
3、MY CORPS OF ENGINEERS (Preparing Activity) NAVAL FACILITIES ENGINEERING COMMAND AIR FORCE CIVIL ENGINEER SUPPORT AGENCY Record of Changes (changes are indicated by 1 . /1/) Change No. Date Location 1 Jun 2006 Forward updated 2 Sep 22 2009 Removed ANF from document number _ This UFC supersedes TM 5-6
4、88, dated 12 November 1999. The format of this UFC does not conform to UFC 1-300-01; however, the format will be adjusted to conform at the next revision. The body of this UFC is a document of a different number. Provided by IHSNot for ResaleNo reproduction or networking permitted without license fr
5、om IHS-,-,-UFC 3-510-01 1 MARCH 2005 Change 2 22 September 2009 FOREWORD 1 The Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and provides planning, design, construction, sustainment, restoration, and modernization criteria, and applies to the Military Departments, the Defens
6、e Agencies, and the DoD Field Activities in accordance with USD(AT distribution is unlimited. FOREIGN VOLTAGES AND FREQUENCIES GUIDE ParaaraDh therefore, supply voltage does not pose a problem. (2) General output voltage con be increased or decreased by using on appropriate transformer. However, sin
7、ce generators ore typically used to supply backup power when the utility power source foils, and or ore used in addition to the utility power source, it is necessary for the generator to provide o 50 Hz volt- age source to match the utility supply. Therefore the user must purchase a generator config
8、ured for 50 Hz operation. (3) Automatic source transfer switches ore sensitive to supply voltage frequency and amplitude because they ore electronically controlled and hove power supplies that expect to operate on 60 Hz and rated voltage. Once again, supply voltage level is not a problem since trans
9、formers ore available to adapt voltage levels. Supply frequency, however, may be Q problem depending on the type of power supply the electronics use. (4) Related equipment includes meter centers, and sockets or receptacles. Meter centers ore sensitive to volt- age level and frequency. Consequentiy,
10、using a 60 Hz meter center in o 50 Hz environment may result in inac- curate readings. However, meters ore readily available in Q variety of voltage levels and 50 Hz configurations. (5) Sockets or receptacles ore needed when foreign consumer products ore to be used with the power sys- tem. Receptacl
11、es ore configured for different voltage levels, and these configurations vary in different coun- tries. It is important that the standard receptacle style for a given voltage be used to ovoid confusing the user and creating Q potential safety hazard. (6) Capacitors ore used in on electrical distribu
12、tion system to odjust the power factor or phase angle between the voltage and current waveforms. It is desir- able to hove Q phase angle close to zero, or a power factor close to one so that most of the power transferred to the load is real power. Real power is the only part of the total kilovolt-am
13、peres transferred that con do work. The balance is called reactive power and cannot do any useful work. Th e operation of Q capacitor depends on the supply frequency, since a capacitors impedance, Xc, is related to the capacitance and fre quency of the current passing through it by the equation xc =
14、 1 (j27tf C), where C is the capacitance in farads and j equals the square root of -1. b. Electrical protection. Electrical protection devices vary in their sensitivity to supply frequency. All protec- tion devices ore available in Q wide range of voltage ratings so the level of the supply voltage i
15、s not a con- cern. The main concern with protection devices is the change in response time from 60 Hz to 50 Hz. These devices are coordinated to protect the distribution sys- tem from faults (shorts or spikes) but ore connected so they do not trip when anticipated voltage spikes (that is, motor star
16、ting) occur. The power system design engi- neer must be sure to use the proper trip curves for the environment when coordinating protective devices. Trip curves for 50 Hz ore readily available from vendors contacted in this study. The only device designed dif- ferently for 50 Hz and 60 Hz is the cir
17、cuit breaker. e 2-4. Medium voltage distribution equipment: 50 Hz + 60Hz. In this section medium voltage transformers, switchgear and associated auxiliary devices will be examined with respect to frequency and voltage changes. o. Medium voltage distribution transformers. Distribution transformers or
18、e key components in any electric power distribution system. It is important that they ore properly matched to their environment. Issues related to operating Q 60 Hz transformer from a 50 Hz power source were discussed earlier in this manual. The emphasis here will be on discussing issues concerning
19、operating 50 Hz transformers in a 60 Hz environment. (1) An important parameter to consider when oper- ating a transformer, or other iron corebased devices, is the ratio of amplitude to frequency of the applied volt- age. The ratio obtained using the nameplate rated volt- age and frequency should be
20、 compared with the ratio available at the proposed site. If the ratio is less than or equal to that obtained using the nameplate quantities, magnetic saturation will not be a problem at the new site. Any time the ratio is higher than nameplate, the manufacturer should be contacted to ensure that the
21、 transformer has enough reserve available to accommo date the increase in operating magnetic flux density. (2) For example, consider o transformer that is brought over from Germany where it was used on a 10 kV, 50 Hz distribution system. It WQS determined that the electrical insulation system of the
22、 transformer WQS rated for 15 kV. It is desired to use the transformer on a 13.8 kV, 60 Hz system. Considering the magnetic cir- cuit, the volts-per-hertz ratio of the 50 Hz transformer is 200 (i.e., 10 kV/50 Hz). On the new supply the ration would be increased to 230 (that is, 13.8 kV/60 Hz), requi
23、ring a higher magnetic flux density in the iron core. This increase could potentially saturate the iron core and overheat the transformer. Alternatively, this 2-4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TM s-688 transformer could be used on Q
24、 7.2 kV/60 Hz system (120 volts-per-hertz ratio), where saturation would not be a problem. (3) A few words should be mentioned concerning iron core loss in transformers. The two primary compo nents of core loss ore eddy-current loss and hysteresis loss. Eddycurrent loss is the term used to describe
25、the power loss associated with circulating currents that are found to exist in closed paths within the body of Q iron material and cause undesirable heat production. Hysteresis loss represents the power loss associated with aligning and realigning the magnetic domains of iron in accordance with the
26、changing magnetic flux. Both components ore dependent on the frequency, OS shown in the following equations: peddy - current = Ke f 2 B2rn T2v physteresis = Khf ev where, K = constant value dependent upon material f = frequency of variation of flux B = maximum flux density v = total volume of the ma
27、terial Z= lamination thickness. (4) It should be noted that, even though frequency increases when using 50 Hz transformers on a 60 Hz- based system, the voltagetofrequency ratio will typical- ly be lower, and hence, the maximum flux densities B will be lower. The result is that core-losses will gene
28、rally not increase OS a result of the higher frequency used. (5) Other key parameters ore voltage and current. To maintain insulation system integrity, rated voltage and/or current for the transformer should not be exceeded. A transformer con be operated on lower than rated voltage; however, its cur
29、rent rating must not be violated. Also, the secondary voltage must be matched to the proper voltage levels. (6) In addition to having on iron core, windings, and insulation system, distribution transformers may include top changers and auxiliory devices. Auxiliary devices might include fans, current
30、 transformers, pressure relief devices, and lighting arresters. Once again, attention should be focused on devices that use a magnetic field for transferring or converting energy, such as instrument transformers and small motor drives. Even if the volt- age-to-frequency ratio is found to be lower, m
31、anufoc- turers should be contacted to make sure that all linear and rotating drive mechanisms will develop adequate force and torque to function properly. b. Medium voltage switchgeor. Switchgear is Q gen- eral term covering switching and interrupting devices alone, or their combination with other a
32、ssociated con- trol, metering, protective, and regulating equipment. Common switchgear components include the power bus, power circuit breaker, instrument transformers, control power transformer, meters, control switches, protective relays and ventilation equipment. The ratings of switchgear assembl
33、ies ore designations of the oper- ational limits under specific conditions of ambient tem- perature, altitude, frequency, duty cycle, etc. For exam- ple, the performance of some 50 Hz magnetic type cir- cuit breakers may be altered slightly when operated on a 60 Hz power system. Switchgear manufactu
34、rers should always be consulted to identify the frequency response of circuit breakers andbll auxiliary devices. 2-5. Safety and security equipment. Safety and security equipment includes fire detection systems, burglar alarm systems, doorbells, and surveillance systems. This equipment typically ope
35、r- ates on low voltage, either alternating current (AC) or direct current (DC), generated initially by a power supply. Acquiring the proper power supply to convert from the supply voltage to the low voltage that these systems expect (typically 6 to 12 VAC or VDC) is the key to proper operation of th
36、ese systems in foreign environments. Power supplies of 50 Hz/120 VAC usually ore available from vendors of these systems, and a transformer con be used to step o 240 VAC supply down to Q 120 VAC foreign envi- ronment. Therefore, derating is not necessary for these items, although Q transformer may b
37、e needed to step high voltage supply levels down to 120 VAC for the power supplied to these systems. Most ven- dors of safety and security equipment con configure their equipment to 50 Hz and a variety of voltage levels. 2-6. Communication equipment. Communication equipment encompasses public addres
38、s systems and sound systems, both of which operate on o low-voltage DC supply generated by o power supply. Power supplies ore available to operate on 50 Hz and 240 V supply voltages. In cases where only 120/50 Hz supplies ore available, a step-down transformer con be used to step o 240 V supply down
39、 to 120 V. The vendors contacted in this study hove stat- ed that they provide 50 Hz power supplies. 2-7. Lighting. Lighting con be divided into incandescent, fluores- cent, and high intensity discharge (HID) categories. Incandescent lighting is not frequency-sensitive, whereas fluorescent and HID l
40、ights ore started by a ballast that is sensitive to voltage level and frequency. 2-5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TM 5-688All types of lighting are sensitive to the supply voltagelevel and cannot be derated for voltage. For example
41、,subjecting a 120 V incandescent lamp to a 240 Vsource will result in the lamp burning twice as hot,causing rapid lamp failure. Subjecting the iron coreballast use in many HID and fluorescent fixtures totwice its rated voltage will saturate the ballast and willsubject the fixture to much more than i
42、ts rated current.As with transformers and motors, 60 Hz iron-core bal-lasts can also be saturated when operated at 50 Hz.At first thought, frequency dependence may not be OSmuch of a problem with electronic ballasts since, inmost cases, the AC voltage source is first convertedback to a high frequenc
43、y AC source, and therefore,the voltage source that is actually impressed acrossthe lamp is decoupled from the 60 Hz AC source.However, the power supply used to power the elec-tronics in these ballasts must be capable of 50 Hzoperation.2-8. Other electrical equipment.Other electrical equipment includ
44、es motors, motorstarters, computer power supplies, and clocks.a. Typically, motor starters are sensitive to both supplyvoltage level and frequency. The most commonly usedmotor starters consisters of a coil, thermal overloads,and a set of contactors (contacts). The thermal over-loads, which are essen
45、tially circuit breakers, and thecontactors are rated to handle a certain amount of cur-rent. Since at 50 Hz, a motor of a given horsepowerrating will draw more current than an identically-ratedmotor would draw at 60 Hz, the thermal overloads andthe contactors must be sized accordingly.b. Computer po
46、wer supplies include voltage regula-tors, isolation transformers, transient voltage suppressortransformers, computer regulator transformers, andpower conditioning transformers. Computer power supplies are sensitive to both frequency and voltage level.c. Clocks are sensitive to supply frequency and v
47、olt-age. Clocks rely on the frequency of the supply voltageto keep correct time, so a clock designed for 60 Hzwill not keep correct time at 50 Hz. The motor that runsthe clock is also sensitive to supply voltage level.Therefore, a clock must either be purchased config-ured for the supply voltage lev
48、el, or a transformer mustbe used to convert the supply voltage level to theclocks rated voltage level. Clocks cannot be deratedfor frequency, and therefore clocks designed for 50 Hzmust be purchased.2-6Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
49、TM 5-688CHAPTER 3EQUIPMENT DERATING3-1. Derating under 50 Hz conditions.Derating factors for 50 Hz operation are developeddifferently for different types of equipment. Deratingfactors for HVAC, electrical distribution and protec-tion, safety and security equipment, communicationequipment, lighting, and other electrical equipmentare discussed below.3-2. Heating, ventilating, and air conditioning(HVAC) for derating.The frequency
