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8QLQWHUUXSWLEOH 3RZHU 6XSSO\ 836 3ODQQLQJ DQG ,QVWDOODWLRQ *XLGH 3UHIDFH Solidstate Controls, Inc., is pleased to furnish this Planning and Installation Guide to inform you about the UPS equipment and assist you in its installation. The planning for an installation of electrical equipment as critical to your company as an uninterruptible power system (UPS) deserves, and in some localities requires, the attention of a qualified engineer or qualified electrician.
+RZ 7R 6L]H 8SV /RDGV Good data on power consumption is often hard to get for small loads such as personal computers. Most equipment below, for example, 800 Watts, will be 120 VAC, single phase, 60 Hz. rated (Sometimes with a dual rating for 50 Hz. And 240 VAC for overseas usage). Usually, each component of the computer system will have a tag placed near the location the power cord enters the device.
Notice that the wattage is not known nor is the power factor. Since in the U.S., 120 VAC is the nominal value of input voltage, we can calculate the CPU’s volt-amperes (VA) directly: IBM CPU – 120 V x 1.5 A = 180 VA If we use our rule of thumb and assume a power factor of 0.8, then 180 VA x .8 = 144 Watts (W) )RU WKRVH ZKR ORYH GHWDLOV The value difference between 180 VA and 144 W, 36 VA circulates as unused power between the input power source and the computer.
Three phase loads can be difficult to size, especially if there is a mixture of both single and three phase devices in the system. Please call SCI for sizing assistance for those three phase applications. For the truly dedicated, Section III of the SCI UPS Installation and Planning Guide discusses three phase applications. PROPERTY OF SOLIDSTATE CONTROLS, INC.
HFWLRQ , (OHFWULFDO &RQVLGHUDWLRQV $ 836 6L]LQJ ² /RDG 6WXG\ The first step in sizing the UPS is to perform a thorough Load Study. When performing the Load Study, it is important that all possible considerations be made for present needs and any planned future expansion. All loads need to be analyzed with respect to various parameters, as described below.
A single phase UPS with a 120 V output can supply only a 120 V load. However, a three phase UPS with a 208Y/120 V output can supply either a 120 V single phase load, a 208 V two phase load, a 208 three phase load, or a 208Y/120 V, three phase load. In determining the size of a three phase UPS, single phases loads can be distributed between each of the three phases. However, one large single phase load can be connected to only one phase of a three phase UPS.
Selecting from our standard sizes, we find that we must supply a three phase, 40 kVA UPS which has a 111 amp AC output per phase. One can see that “A” phase is 84% loaded, while “B” and “C” phases are only 27% loaded, which means that there is substantial room for additional single phase loads for future expansion – but only limited expansion room for three phase loads. In the previous example, we have been looking at continuous full load currents.
If it is not possible to measure the actual current, it may be necessary to use one of the following: 2. Obtain load profile from manufacturer for the individual loads. This will probably be necessary for new installations. Add to this any lighting, alarms and security loads which are required. 3. In existing installations, check the capacity of the step-down isolation transformer supplying the critical load or check the size of the distribution panel feeding those loads. 4.
unit to maintain a constant output voltage with a varying input voltage. A longer conduction period increases the DC output voltage and, conversely, a shorter period lowers the output voltage. When the input voltage is high, the thyristors are gated on later during each half cycle. As a result, in order to provide constant power, we will necessarily see a high current spike at this point which we will refer to as form factor or crest factor.
supply this transformer mounted in a matching cabinet, if desired, or can supply a standard transformer of another manufacturer in their own floor-mounted enclosure. Some customers may wish to have their own electrical contractor supply and install this along with other necessary equipment. ) 2XWSXW 'LVWULEXWLRQ 3DQHOV The customer’s existing distribution panels, which previously supplied the computer loads, should be re-evaluated before utilizing with the UPS.
not been exceeded. If this is not being done, one would be advised to contact experts in that field to aid you in performing this important periodic analysis. One should also be aware that some computer peripherals, such as printers, are themselves noise generators, and that proper filters should be used on these lines to prevent the transmission of this noise from one device to another.
6HFWLRQ ,, 3K\VLFDO (QYLURQPHQWDO &RQVLGHUDWLRQV 6LWH VHOHFWLRQ DQG SODQQLQJ The site selected for the UPS should be chosen with care since the type and amount of site preparation required will vary according to the specific location and its relative location to the load. $ /RFDWLQJ WKH 836 The relative location of the UPS to the load is important for several reasons.
( (TXLSPHQW 0RXQWLQJ 5HTXLUHPHQWV The Inverter and Rectifier/Charger This equipment is designed to set on any floor which is adequate to handle the loading. No bolting to the floor is required, although some units have provision for bolting should the customer wish to do so.
Moving Equipment At the unloading area, a forklift may be neede3d to remove the equipment from the truck. The forklift capacity should be checked to be sure it is adequate to handle the weight of the equipment. This information is available from the data sheets. Note that the date sheets give total weight. If the outline drawing shows two equally sized cabinets, the weight should be divided with approximately 60% in one cabinet and 40% in the other.
location which is subject to the same temperature variations as allowed for the Inverter and Rectifier/Charger, i.e., 32° to 104°F. . 9LEUDWLRQ Standard UPS equipment is built to withstand mild, intermittent building vibration. However, the equipment should not be considered to be seismic or earthquake proof. It is impossible to predict a designed vibration tolerance for conditions that might be encountered in various installations.
6HFWLRQ ,,, %DWWHU\ 6HOHFWLRQ All SCI UPS Systems are designed to operate from virtually any commercially available battery bank which exhibits the proper voltage range and current capacity to power that particular UPS. Choosing the proper battery for the application then becomes one of examining these various parameters and choosing the one most suitable for the particular application.
6HDOHG 0DLQWHQDQFH )UHH %DWWHULHV As previously discussed, sealed batteries are those which, due to special construction, do not normally vent gas into the atmosphere, and because they are sealed, require no routine water additions. Because they do not gas, they are well suited for installation into an office area or computer room environment where special ventilation would be difficult or impractical to provide.
6HFWLRQ ,9 %DWWHU\ 5RRP 3K\VLFDO $QG (QYLURQPHQWDO &RQVLGHUDWLRQ $ %DWWHU\ 5RRP 7HPSHUDWXUH Since battery operation results from a chemical reaction, temperature plays a significant role in performance and life. A standard temperature of 77°F (25°C) is used to rate the batteries. It is recommended that the battery room temperature be maintained as close as possible to this temperature (72-80°F would be acceptable).
2. Ventilation All stationary batteries produce hydrogen gas while they are being charged. Gassing does not become a problem until approximately 70% of the charge has been returned to the cells. The battery room must have adequate ventilation, preferably to the outside, to prevent the build-up of hydrogen gas in the room. The size of the room and the size of the battery bank will determine the amount of ventilation required.
6HFWLRQ 9 6WDUW 8S 6XSHUYLVLRQ All UPS Systems which are not plug-in compatible, should be able to be installed by a qualified electrician. Further, SCI recommends that the customer purchase start-up supervision to be sure that the equipment is installed and operating properly. Severe damage could result if the equipment is installed improperly and start-up initiated. Also, even though the equipment was tested and operating properly at the factory, damage could have been sustained during shipment.
6HFWLRQ 9L 6HUYLFH $QG 7UDLQLQJ SOLIDSTATE CONTROLS, INC. is dedicated to providing the most reliable Uninterruptible Power Systems available. Even as exacting as we build our equipment, we recognize that some service and repair may one day be required. With this in mind, SCI has provided for UPS maintenance by having available a strong field service team, offering service training to those customers who elect it.
6,1*/( RU 7+5(( 3+$6(" Although it is common for UPS larger than 10 KVA to be specified with three phase output, industrial distributed control systems rarely consist of any component that actually requires true three phase power. Particularly on smaller systems (under 50 KVA), there are some very real technical advantages to single phase distribution. Unlike a typical building distribution system which has relatively low source impedance, an inverter is a high impedance power source.
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