Have you ever wondered why some powers are in watts, some in AMPS, a bit 'in Volt, and some in KVA? For many in the industry hosting this can be a very confusing topic. Admit it, business professionals of the contents probably are not electrical engineers, and most electrical engineers know nothing about the creation and distribution of content.
This article explains in simple terms the difference between the great powers, and describe when each is to be used in architectural planning network.
According to APC, the main difference between watts and volt ampere is the Watt rating determines the actual draw energy from a power source and the heat generated by the equipment. The VA rating is used for sizing equipment such as switches, cables, and UPS. The VA rating is usually equal to or higher than the watt rating, as it includes the "power factor" in the calculation.
Power Factors
The power factor is a calculation used to explain the difference of power supplies used to convert alternating current into DC for use in electrical appliances and computer equipment. There are two types of power supplies - capacitor of the input power and the correct power factor.
factor corrected power supplies are used in most high-end processing and switching equipment, and have a relationship 1VA: 1W - allowing a simple calculation to scale electrical and UPS equipment. So in theory, if the power factor is 1: 1, and your UPS is a 80KVA UPS, then you would be able to charge the UPS 100% of its rating.
old electrical equipment, as well as the majority of low-end power supplies and video equipment in condenser use computer input and have a power factor anywhere from.55 to.75 times the VA rating.
Typically when resizing an uninterruptible power supply for use in a data center that you will use a load factor of 60% on the UPS. If you overload a UPS is almost certain to fail during a power outage, as the draw of the batteries will exceed the UPS's capacity. Most new UPS automatically switches to bypass the battery when there is an overload condition. It represents the load factor of 60% for the high probability that most of the design energy plants through the UPS will be in a category that has a power factor of between.55 and.75.
Example 1
You have a 10KVA UPS. Your data center has racks self-assembled low-end computers with a total score of estimated 000 watts. The UPS will be very similar to fail, as the power factor is probably around.70. You would need at least 12.85KVA to properly back up your data center.
Example 2
You have a 10KVA UPS. Your data center has racks self-assembled low-end computers with a total score of 00 estimated watts. Its UPS will be able to handle the load, as the correct rating power factor takes approximately 8.5KVA of the UPS.
Some modern UPS will actually say the average power factor, real-time load capacity of the UPS.
Some Useful conversion factors
or refrigeration
- 1 watt = .86 kcal / h
- 1 Watt = 3,412 Btu / h
- 1 watt = 2.843 x 10-4 tons
- 1 ton = 0 Btu / min
- 1 ton = 12,000 Btu / h
- 1 ton = 3,517.2 W
or kVA Conversions
phase
kVA = V ï? - A ÏEUR I? - ÏEUR √3 / ïEUR 1000
phase
kVA = V ï? - ÏEUR A / ïEUR 1000
The formulas
kVA = voltage x current (amperes)
Watts = VA x PF
BTU = Watt x 3:41
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