Ex PC-Workstations, Ex-PCs

Ex Automation technology

Ex-p Pressurized enclosures

F830 F840 F850-SYST F850S F850U F860S F870S OEM SR852 SR853

Power relay SR853.8 - Description



The power relay SR853 is designed to separate non intrinsically safe feed lines, for instance in combination with a pressurized enclosure system.
The power relay can be placed in hazardous area, Ex- Zone 1 respectively Ex Zone 21.

Safe switch off

For this purpose the SR853 has 4 gavanically separated relay contacts, which open if the control voltage is low. The opening is safe with one fault (acc EN 954-1, cat 3), because there are two independent serial relay contacts for each line.

Switch power: 4kW

The four relay contacts combined with the high switch power (400 V, 16 A, 4 kW) can disconnect a three-phase system with one compact unit.

Simple cascading

Using the terminal pairs 1/2/3 and 26/25/24 it is possible to cascade several power relay units.

Modular assembly

The SR853 is available as

  1. build in compact Ex e terminal box
  2. Module without housing for mounting inside of a separate certificated Ex e housing
  3. optional for mounting on a 35 mm rail acc. EN 50022.
  last modified: 07.12.2017