Page 137 - Pipeline Rules of Thumb Handbook

124 Pipeline Rules of Thumb Handbook

Electrical formulas

Single Phase eff = Efficiency (decimal)
PF = Power Factor (decimal)
KVA = VA 1 000 kVA = Kilovolt amperes
,
kW = Kilowatts
hp = ( VA ¥ eff ¥ PF) 746 hp = Horsepower
rpm = Revolutions per minute
kw = ( VA ¥ PF) 1 000
,
=
PF kW kVA

Three Phase
(
,
-
Torque ft lb) = hp ¥ 5 250 rpm
12
( 3 V ¥ A) 1 000
,
Moto kVA = ( hp ¥ 0 746 ) eff ¥ PF
.
r
( 3 VA ¥ PF eff) 746
/
12
¥
Motor kW = ( hp ¥ 0 746 ) eff
.

( 3 VA ¥ PF) 1 000
12
,
V = Line-to-line volts
A = Amperes ( kW ¥ 1 000 3 12 ¥ VA
)
,

Full load currents—single phase transformers
Voltage—Volts
kVA
Rating 120 240 480 2,400 4,160 7,200
1.0 8.3 4.2 2.1 0.4 0.2 0.1
3.0 25.0 12.5 6.3 1.3 0.7 0.4
5.0 41.7 20.8 10.4 2.1 1.2 0.7
7.5 62.5 31.3 15.6 3.1 1.8 1.0
10.0 83.3 41.7 20.8 4.2 2.4 1.4
15.0 125.0 62.5 31.3 6.3 3.6 2.1
25.0 208.3 104.2 52.1 10.4 6.0 3.5
37.5 312.5 156.3 78.1 15.6 9.0 5.2
50.0 416.7 208.3 104.2 20.8 12.0 6.9
75.0 625.0 312.5 156.3 31.3 18.0 10.4
100.0 833.3 416.7 208.3 41.7 24.0 13.9
125.0 1,041.7 520.8 260.4 52.1 30.0 17.4
167.5 1,395.8 697.9 349.0 69.8 40.3 23.3
200.0 1,666.7 833.3 416.7 83.3 48.1 27.8
250.0 2,083.3 1,041.7 520.8 104.2 60.1 34.7
333.0 2,775.0 1,387.5 693.8 138.8 80.0 46.3
500.0 4,166.7 2,083.3 1,041.7 208.3 120.2 69.4