For Transformer, we should choose two types of cable such as the primary side and secondary side. The rating of the cable should be 150% of the full load current. i.e if your transformers primary current is 450 Amps means, you should choose 450 *150% = 675 Amps capacity size cable.
How do I calculate wire size?
Divide the voltage running through the cable by your target current. If, for instance, 120 volts will act on the cable, and you want 30 amps to run through it: 120 / 30 = 4. This is your target resistance, measured in ohms. 30,000 x 1.724 x 10^-8 = 0.0005172 ohm sq.
For example, a 75-kVA, three-phase, delta-delta connected transformer will be installed in an industrial facility. The primary or input voltage will be 480V, and the primary conductors will be 1 AWG THHN conductors.
Copper and aluminium are the two conductors used in transformer windings. In distribution and small power transformers, aluminium–aluminium windings have been successful. For large power transformers, a copper–copper design is more common.
Calculate an example as follows. A 120-volt motor has a load amperage of 5 amps. Multiply 120 volts times 5 amps this equals 600VA now lets multiply the 125 percent start factor. Take 600 times 1.25 this equals 720VA and most transformers are sized by a factor of 25VA or 50VA.
How do you determine AWG wire size?
Stranded wire gauges should be measured by calculating the equivalent cross sectional copper area. First, measure the bare diameter of a single strand and locate the circular mils value in the row that matches your measurement. Second, multiply the circular mils by the number of strands in the cable.
45kVA transformer — Per Table 250.122, 70A primary protection (Step 2) requires an 8 AWG copper conductor.
Therefore, RMS value of emf per turn = 1.11 x 4f Φm = 4.44f Φm. This is called the emf equation of transformer, which shows, emf / number of turns is same for both primary and secondary winding. For an ideal transformer on no load, E1 = V1 and E2 = V2 .
Different Types of Transformers and Their ApplicationsStep-Down Transformer. Step-Down Transformer. Step-Up Transformer. Step-Up Transformer. Isolation Transformer. Isolation Transformer. Iron Core Transformer. Ferrite Core Transformer. Toroidal Core Transformer. Air Core transformer. Transformers used in Power domain.More items •14 May 2019
An oversized transformer will drop your power factor (well all transformers drop your power factor but an oversized one doesnt have as much load to compensate). Did a transformer swap last year because the installed unit was sized 3X larger than needed for an expansion that never happened.
What does 10 AWG wire mean?
If our wire is copper, that 40 AWG conductor, with a 9.61 area, has a resistance of 1080 ohms per 1000 feet; the 10 AWG, with approximately 1000 times the area, has a resistance of just about exactly one ohm.
What size is 4 0 wire?
American Wire Gauge Conversion Chart (AWG)Gauge No.InchesMillimeters7/00.65130016.546/00.58004914.735/00.51654913.124/00.46000011.6864 more rows
Iprimary = (20 x 1000)/480 = 20,000/480 = 41.6 amps. Note: If you had a 3-phase transformer, the formula would be Iprimary = KVA x 1000/(Vprimary x 1.732). The 1.732 accounts for the 3-phase configuration. Find the circuit breaker size for the primary side of the transformer by multiplying Iprimary by 1.25.
In lieu of transformer inrush data, the rule of thumb is to select a fuse size rated at 300% of the primary full-load current and round up to the next larger standard size.