Siemens sirius System Manual page 116

3RT1/3RH1 contactors
Regulations
Safe isolation in the
case of 3RT1 and 3RH1
contactors
3-8
IEC 61 140 (replacing VDE 0106 Part 101/IEC 536) lists basic requirements
that can be met using safe isolation between circuits in electrical equip-
ment.
Basic requirements are, for example:
• Double or reinforced insulation
• Protective screening
• Combination of double or reinforced insulation and protective screening
The insulation must be resistant to aging throughout the expected service
life.
Circuits without protective extra-low voltage or functional extra-low voltage
do not require safe isolation.
If the conducting paths of a contactor are operated with different voltages,
the requirements for safe isolation must be met.
In the case of the 3RT1 and 3RH1 contactors, safe isolation is ensured up to
the following voltage:
• Safe isolation between the different main conducting paths is always
400 V.
• Safe isolation between the different main conducting paths and the coil
connection is always 400 V.
• The following table lists the values for safe isolation between the main
and auxiliary conducting paths and the coil connection:
Aux. switch
at front
at side
Coil connection
Table 3-5: Safe isolation
(*) Only applies to 4-pole auxiliary switch blocks at the front
All the data are power system specifications with 10% overvoltage in volts
[V].
400 V + 10% corresponds to 415 V + 5% and 500 V + 10% corresponds to
525 V + 5%.
Attention
In the table, the voltage that can cause electric shock and that must be
safely isolated is critical. If the voltages 400 V and 24 V are to be safely iso-
lated from one another, contactors with safe isolation up to 400 V must be
used between the two points of connection used.
3RT1 and 3RH1 contactors
Frame size Frame size
S00 S0
Main con- Main contact
tact
690 (*) 500
- 690
400 400
Frame size Frame size
S2 S3
Main contact Main contact
500 500
500 690
400 400
SIRIUS System Manual
GWA 4NEB 430 0999-02b