| Cities | Type of current |
Frequency of current | Number of phases | Nominal voltage | Number of wires | Frequency stability |
| All | a.c. | 60 | 1,3 | 127/220 | 2,3,4 | yes |
| Type(s) of plug | |
| Type A | ![]() |
| Type B | ![]() |
| Note(s) | |
| 1 = The neutral wire of the secondary distribution system is grounded. | |