Part Number : 3TK2804
Function : Contactor Safety Combination
Package : Module type
Manufactures : Siemens
The internal control circuit of the contactor safety combination is designed according to DIN EN 60204, Part 1 (VDE 0113, Part 1), para. 22.214.171.124, so that in the case of a fault in one of the contactor relays the function of the safety circuit is maintained. The supply voltage must meet the requirements of the DIN EN 60204 (VDE 0113, Part 1) (the terminals “L-/N; A2“ must be connected to that side of the control current circuit which is linked to the protective conductor system).The contacts of the contactor relays are checked for proper opening and closing in every ON and OFF cycle of the machine to be switched.
This is, for instance, done by
– connecting and disconnecting the control voltage with the main switch,
– activating and deactivating the EMERGENCY-OFF unit
– opening and closing of the protective screen.
The contactor safety combinations can be used in EMERGENCY-OFF circuits
and for monitoring protective devices (e.g. protective screens).