INTRODUCTION:
A GLUPS is a UPS battery backup with a transformer integrally built
inside, that allows you to take your US voltage products to Europe without
changing anything. The following is a description of why you may need one,
and what goes into the voltage charts, to make it work for you. In general,
this discussion applies to the transformer, with the assumption that you
understand the UPS.
Voltage and frequency (Hz) vary throughout the world, and, in some cases, within the same country. Most appliances /computers/telecom gear are made to operate on a single voltage and frequency. When using electrical equipment designed for a specific voltage, it is necessary to adjust the local voltage to the voltage for which the equipment was designed. This is done with a transformer which comes inside a GLUPS.. For the purpose of this article, all types of computers, tools, equipment, machinery, etc. shall be referred to as the load. An autotransformer is a tapped winding transformer that changes the voltage available locally to the voltage required by a particular load. Thus, a load may operate anywhere around the world, as long as a transformer is available to convert the local voltage to the voltage it requires.
An autotransformer, with a single tapped winding, is generally preferred to an isolation transformer, with 2 separate windings, for many reasons. An autotransformer is much smaller and lighter than an isolation transformer. It also has better voltage stability and greater overload tolerance. Autotransformers perform in much the same way as the transformer that the electric company uses to bring electricity to a building. No transformer of any type can change frequency. Frequency is unimportant to the normal operation of most loads: most motor driven loads will simply run at a slightly different speed than they did at their rated frequency; simple heating equipment (broilers, coffee pots, etc.) will operate with no problem at all. However, motor loads whose proper operation depends upon frequency, such as clocks, turntables, timers, cassette players, etc. must be converted for voltage with a transformer and then also have their gears and/or pulleys changed for speed correction.
Some motor loads are heat sensitive to frequency changes. To avoid overheating sensitive motors, such as those that continuously stop and start, or run non-stop -- refrigerators, air conditioners, washing machines, shop equipment, etc., it is good practice to run 60 Hz motors at 10% less voltage when operated on 50Hz (e.g. 115 V 60 Hz equipment should operate at 100 - 105 V at 50 Hz). Conversely, to obtain full power from a 50 Hz motor operated on 60 Hz, it is necessary to supply it with 10% extra voltage (e.g. 220 V at 50 Hz should be operated at 250 - 260 V at 60 Hz).
CHOOSE A GLUPS TRANSFORMER
Example 1
You wish to use a 120 V 60 Hz electric drill on 230 V 50 Hz. The nameplate reads:
INPUT: 120V 50/60Hz 2.4 A
This means that the required operating voltage is 120 Volts, with a current of 2.4 Amps. Thus, the load is found to be 288 VA, so a 300 VA transformer
should be used. The frequency will only slightly affect the drill speed.
Example 2
It is desired to operate several different 120 V appliances one at a time on 230 V...
Computer Printer 120 V - 0.9 A = 108 VA
Vacuum Cleaner 120 V - 11.9 A = 1428 VA
Sewing Machine 120 V - 1.2 A = 144 VA
Since they will be used one at a time , choose a 1500 VA transformer Powerstar-14) that will be sufficient for the largest item, the vacuum cleaner. Of course, the other 2 loads, the sewing machine and printer, may be operated at other times, singly, or even at the same time since their total VA is only 252.
Example 3
It is necessary to operate several appliances at the same time...
Microwave Oven 120 V - 6.25 A = 750 VA
Electric Fan 120 V - 1.2 A = 144 VA
CD Player 120 V - 0.7 A = 84 VA
Total load = 978 VA
Choose a transformer of 1000 VA capacity Powerstar-13, which is closest to, but not smaller than, the total VA of all appliances used). This will supply all of the above loads all at once or one at a time if you so choose.
GROUNDED VS UNGROUNDED
HELPFUL HINTS
TRANSFORMER CONSTRUCTION
GUARANTEE
ALL THAT IS LEFT TO SAY!
Because of our extensive inventory, most PowerStar transformers can be shipped the same or next day. Larger production orders can be scheduled to meet JIT or other delivery schedules. This means that when you need transformers now you get them now.
POWERSTAR INC - 9073 SHADY GROVE COURT - GAITHERSBURG, MARYLAND 20877 - 800-208-5556, 301-948-0713