| Subject | English | German |
| tech. | APC lockout power failure relay | Aufbaeumregler-Sperrelais bei Stromausfall |
| gen. | phase failure relay | Phasenausfallrelais |
| PSP | relay failure for elementary relays | dauernder Relaisfehlzustand eines Elementarrelais |
| PSP | relay failure rate | Relaisausfallrate |