 |
| undervoltage: 79 phrases in 15 subjects |
| Caspian | 1 |
| Electrical engineering | 8 |
| Electronics | 11 |
| Energy industry | 3 |
| Energy system | 1 |
| General | 4 |
| Makarov | 1 |
| Military | 1 |
| Nautical | 2 |
| Power system protection | 3 |
| Sakhalin | 1 |
| Security systems | 1 |
| Switches | 17 |
| Technology | 24 |
| Telecommunications | 1 |