Electrical power engineering

Electrical power engineering is one of many electrical engineering’s sub-fields that deal with the study and application of three phase electricity. The benefits of three phase systems are more efficient than single phase systems. Electricity is produced by rotating three coils or windings are spaced 120 degrees apart through a magnetic field. Following are some useful applications:

Three Phase Connection:

Delta and Wye Configurations

Delta-Wye Transformations:

The equivalent resistances for resistors in delta and wye configurations are:

Delta and wye 3 phase transformations

Wire Gage/ 3 phase Transformer Electrical Motor table reference

Wire Gage (AWG)
Transformer			Distance Motor to Transformer (Feet)
HP	Volts	kVA	100	150	200	300	500
1.5	230	3	12	12	12	12	10
2	460	3	12	12	12	12	12
3	230	3	12	12	12	10	8
2	460	3	12	12	12	12	12
3	230	5	12	10	10	8	6
3	460	5	12	12	12	12	10
5	230	7.5	10	8	8	6	4
5	460	7.5	12	12	12	10	8
7.5	230	10	8	6	6	4	2
7.5	460	10	12	12	12	10	8
10	230	15	6	4	4	4	1
10	460	15	12	12	12	10	8
15	230	20	4	4	4	2	0
15	460	20	12	10	10	8	6
20	230	¹⁾	4	2	2	1	0
20	460	¹⁾	10	8	8	6	4
25	230	¹⁾	2	2	2	0	0
30	230	¹⁾	2	1	1	0	0
30	460	¹⁾	8	6	6	4	2
40	230	¹⁾	1	0	0	0	0
50	230	¹⁾	1	0	0	0	0
50	460	¹⁾	4	4	2	2	0
30	230	¹⁾	1	0	0	0	0
60	460	¹⁾	4	2	2	0	0
75	230	¹⁾	0	0	0	0	0
75	460	¹⁾	4	2	2	0	0

Reference NEC 2008
Anyone using this information should rely on your own independent judgment. You need to verify this information and consult for additional local code resources.

View current Electrical power engineering jobs
Home