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