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
3-25
Residual current across
the main contacts
The resistance of the individual measuring circuits across the main contacts
is 4.8 MOhm per pole. This high ohm resistance value eliminates hazardous
shock current, or rather touch potential, on the load side when the contactor
is turned off.
Operational switching
at terminals A1/A2
Operational switching at terminals A1/A2 leads to an error message from
the RLT. The control inputs (PLC, AS-Interface) should be used for the opera-
tional switching. Exceptions are installation shutdowns; the measuring value
remains stored (E²PROM). Use the control inputs PLC/AS-Interface for the
operational switching of the contactor.
3.2.3 Short-circuit protection for SIRIUS contactors
Section 3.7, "Technical specifications", has information on short-circuit pro-
tection. Fuses and circuit breakers can be used as short-circuit protective
devices for the contactors.
The test criteria that apply in this case are stipulated by EN 60 947-4-1
(VDE 0660 Part 102).
Coordination types Two types of assignment are defined in the standards that correspond to
two different levels of damage.
The following applies to both types of assignment:
In the event of a short-circuit, the short-circuit protective device used must
be able to disconnect the overcurrent that occurs. Persons or other parts of
the system must not be put at risk.
Coordination type 1 The load feeder (e.g. motor starter) can be inoperable after each short-cir-
cuit. Damage to the contactor and the overload relay is permissible and it is
only possible to continue operation after defective devices have been
repaired or replaced.
Coordination type 2 After a short-circuit, there must be no damage to the load feeder devices.
However, the contactor contacts can weld if they can be easily separated
again without distorting the contact pieces.
"weld free" There is information in the catalog, for weld free protection of the contac-
tors that needs to be taken into account.
Contactors with over-
load relay
If contactors are combined with an overload relay, a smaller fuse should be
used as specified in the controls catalog for permissible short-circuit protec-
tion fuses for motor starters.