User Manual

Nature of
current
Category Typical applications Relevant
IEC product
standard
a.c. AC-40
AC-41
AC-42
AC-43
AC-44
AC-45a
AC-45b
Distribution circuits comprising mixed resistive and
reactive loads having a resultant inductive reactance
Non-inductive or slightly inductive loads, resistance
furnaces
Slip-ring motors; starting, switching off
Squirrel-cage motors: starting, switching off motors
during run
ning
Squirrel-cage motors: starting, plugging1), inching2)
Switching of electric discharge lamp controls
Switching of incandescent lamps
60947-6-2
AC-7a
AC-7b
Slightly inductive loads for household appliances and
similar applications
Motor-loads for household applications
61095
a.c. and d.c. A
B
Protection of circuits, with no rated short-time withstand
current
Protection of circuits, with a rated short-time withstand
current
60947-2
DC-20A, DC-20B
DC-21A, DC21B
DC-22A, DC22B
DC-23A, DC23B
3)
Connecting and disconnecting under no-load conditions
Switching of resistive loads, including moderate
overloads
S
witching of mixed resistive and inductive loads,
including moderate overloads (e.g. shunt motors)
Switching of highly inductive loads (e.g. series motors)
60947-3
d.c. DC-1
DC-3
DC-5
DC-6
Non-inductive or slightly inductive loads, resistance
furnaces
Shunt-motors, starting, plugging1), inching2). Dynamic
breaking of motors
Series-motors, starting, plugging1), inching2). Dynamic
breaking of motors
Switching of incandescent lamps
60947-4-1
DC-12
DC-13
DC-14
Control of resistive loads and solid-state loads with
isolati
on b
y optocouplers
Control of electromagnets
Control of electromagnetic loads having economy
resistors in circuit
60947-5-1
DC-12
DC-13
Control of resistive loads and solid state loads with
optical isolation
Control of electromagnets
60947-5-2
DC-31
DC-33
DC-36
Resistive loads
Motor loads or mixed loads including motors
Incandescent lamp loads
60947-6-1
DC-40
DC-41
DC43
DC-45
DC-46
Distribution circuits comprising mixed resistive and
reactive l
oads
having a resultant inductive reactance
Non-inductive or slightly inductive loads, resistance
furnaces
Shunt-motors: starting, plugging1), inching2). Dynamic
breaking of d.c
. motors
Series-motors: starting, plugging1), inching2). Dynamic
breaking of d.c. motors
Switching of incandescent lamps
60947-6-2
1) By plugging is understood stopping or reversing the motor rapidly by reversing motor primary connections
while the motor is running.
2) By inching (jogging) is understood energizing a motor once or repeatedly for short periods to obtain small
movements of the driven mechanism.
3) The utilization categories with annex A apply for frequent operations, those with annex B for infre-
quent/occasional operations
Tab. 1.1-1
Examples of utilization categories for low-voltage switchgear as per IEC 60947-1 ed. 5.0 Appendix A.
Copyright © 2007 IEC, Geneva, Switzerland. www.iec.ch
LVSAM-WP001A-EN-P - April 2009
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