| Subject | English | Portuguese |
| el.tract. | earth fault relay | relé de ligação à terra |
| el., meas.inst. | earth fault relay | relé de defeito à terra |
| el., meas.inst. | phase fault relay | relé de defeito de fase |
| PSP | intermittent relay fault for elementary relays | avaria temporária de relé para os relés elementares |