User Guide
Table Of Contents
- 3 3RT1 contactors/ 3RH1 control relays
- 3.1 Specifications/regulations/approvals
- 3.2 Device description
- 3.3 Application and areas of use
- 3.3.1 3RT10 contactors with 3 main contacts for switching motors
- 3.3.2 3RT14 contactors with 3 main contacts for switching resistive loads (AC-1)
- 3.3.3 3RT12 Vacuum contactors
- 3.3.4 3RT13 and 3RT15 contactors with 4 main contacts
- 3.3.5 3RT16 capacitor contactors
- 3.3.6 Contactors with an extended operating range
- 3.3.7 3RH1 control relays
- 3.3.8 3RT10 contactor relays for switching motors (interface) and 3RH11 control relays for switching auxiliary circuits
- 3.3.9 3RA13 Contactor combinations for reversing
- 3.3.10 3RT14 Wye-delta combinations
3RT1 contactors/ 3RH1 control relays
SIRIUS System Manual
GWA 4NEB 430 0999-02 DS 01
3-5
Utilization category for
AC voltages
Definition of AC-1 to
AC-6b
The definitions of the utilization categories AC-1 to AC-6b for main circuits
can be found in the relevant regulations.
The main areas of application for contactors are:
• AC-3 operation: switching of squirrel-cage motors
• AC-1 operation: switching of resistive loads
• AC-4 operation: plugging, reversing, inching
• AC-6b operation: switching of capacitor banks
Test conditions Test conditions for the various utilization categories:
• In AC-1 operation, the contactor must be able to switch 1.5 times the
rated operational current on and off.
• In AC-3 operation, the starting currents of the motors must be controlled.
In other words, the contactor must be able to switch on 10 times the
rated operational current (I
e
), and switch off 8 times the I
e
.
• In AC-4 operation, the contactor must be able to switch off or on 12 times
the rated operational current (I
e
) and 10 times the I
e
. This represents
extremely high stress for contactors because the high starting currents of
the motors have to be switched off.
• In AC-6b operation, the rated values of capacitor loads may be derived
from capacitor switching tests or on the basis of existing experience and
research.
The breaking current is decisive in calculating the electrical service life:
• In AC-1 and AC-3 operation, 1 x I
e
must be assumed.
• In AC-4 operation, 6 x I
e
must be assumed because the contactor also has
to switch off the motor during startup.
AC Utilization category for
AC voltages
Switching capacity I/I
e
Electrical service life I/I
e
On Off On Off
AC-1 Non-inductive load or
a slightly inductive load
1. 5 1. 5 1 1
AC-2 Slip ring motors: switch on,
switch off
44 2.52.5
AC-3 Squirrel-cage motors:
switch on, switch off during
the run
10 8 6 1
AC-4 Squirrel-cage motors:
switch on, plugging or
reversing, inching
12 10 6 6
AC-6b Switching of capacitor banks — —
Table 3-1: Utilization categories, test conditions for AC voltage