Overview of conventional utilization categories
Main circuits alternating current EN IEC 60947-4
| AC-1 | non or slightly inductive loads (cos phi>0,95) |
| AC-2 | Starting, Jogging, Countercurrent Braking of Slip-Ring Motors |
| AC-3 | Squirrel cage motors starting, switching off while running |
| AC-4 | Squirrel cage motors starting, plugging, inching |
| AC-5a | Gas discharge lamps |
| AC-5b | incandescent bulbs |
| AC-6a | Transformers |
| AC-6b | Capacitor banks |
| AC-7a | slightly inductive household appliances |
| AC-7b | Motor-loads for household appliances |
| AC-8a | refrigerant compressor motors with manual reset |
| AC-8b | refrigerant compressor motors with automatic reset |
Main circuits direct current EN IEC 60947-4
| DC-1 | non or slightly inductive loads L/R <1ms |
| DC-2 | Shunt-wound motors, starting, stopping while running |
| DC-3 | shunt-wound motors, starting, reversing, jogging L/R<2ms |
| DC-4 | Series-wound motors, starting, switching off during running |
| DC-5 | Series-wound motors, starting, reversing, jogging L/R<7.5ms |
| DC-6 | Incandescent bulbs |
Contactor relays / auxiliary contacts alternating current EN IEC 60947-5-1
| AC-12 | resistive or semiconductor load with optocouplers |
| AC-13 | semiconductor load with transformer isolation |
| AC-14 | electromagnetic load holding < 72VA (relay) |
| AC-15 | electromagnetic load holding > 72VA (contactors) |
| AC-11 | from IEC 337 replaced by AC-15 |
Contactor relays / auxiliary contact direct current EN IEC 60947-5-1
| DC-12 | non or slightly inductive loads |
| DC-13 | DC Magnets |
| DC-11 | out of IEC 337 replaced by DC-13 |
Circuit-breaker alternating current EN IEC 60947-2
| AC-20 | Connecting and disconnecting under no-load conditions |
| AC-21 | Switching of resistive loads at moderate overload |
| AC-22 | Switching of resistive and inductive loads, moderate overload |
| AC-23 | Switching of motor loads and high inductive loads |
Load switch direct current EN IEC 60947-2
| DC-20 | Connecting and disconnecting under no-load conditions |
| DC-21 | Switching of resistive loads at moderate overload |
| DC-22 | Switching of resistive and inductive loads, moderate overload |
| DC-23 | Switching of motor loads and high inductive loads |