Analog output module 05701-A-0285

Interface Card Connections

System 57 interface cards use a common card with differing numbers of terminal blocks

fitted according to which type of card it is. The picture below illustrates a card with the

maximum number of terminals fitted. The tables show the terminal connections for 5701.

5704 gas and 5704 fire interface cards.

8 Detector Connections

The following sections show generic installation schematics for the most common types of

fire or gas detector and System 57.

8.1 Cable Earthing/Grounding

The detector cable screen or steel wire armour (or braid), as appropriate, should be

connected to the system (protective) earth. This can be achieved where the cable enters the

cabinet by using a metal cable gland, or by other suitable means, and avoiding any screen

‘tails’ within the cabinet.

Where the cable consists of a separate screen sheath and wire armour (or braid), the

armour should be connected, at the cabinet entry, to the protective earth and the screen

sheath should be connected to the GROUND terminal of the Field Interface/Relay Card or to

a suitable instrument earth point.

Note: Where a detector is earthed locally, either to the Earth Stud or through the detector

casing or mounting, to avoid earth loops the screen sheath of the cable should only be

connected at one end, i.e., at the detector or at the Interface/Relay Card.

8.2 5701 Gas Card and Catalytic Type Detector

Catalytic detectors require a three wire connection and the detector documentation will

indicate three connections S, 01 and NS, which are usually brown, white and blue

respectively. At the System 57 end of the field cable, the three detector wires should each be

connected to the respective matching S, 01 or NS terminal on the Field Interface or Relay

Card that is attached to the required Single Channel Display Card.

5701 Gas Card and 2 Wire Loop Powered Detectors

Loop powered detectors require a two wire connection and the detector documentation will

indicate the positive and negative loop connections, usually brown and blue respectively.

At the System 57 end of the field cable the two detector wires should each be connected to

one of either the S, 01 or NS terminals on the Field Interface or Relay Card that is attached

to the required Single Channel Display Card. The two terminals used will vary depending

upon whether the location of the measuring resistance is in the loop supply or return paths.

Transmitters powered from the 5701 Control Card require either three or four wire

connections and the detector documentation will indicate the 0V and +24V power

connections and the positive and negative loop connections.

At the System 57 end of the field cable the detector wires should be connected to the S, 01.

NS, 0V or 24V terminals on the Field Interface or Relay Card that is attached to the required

Single Channel Display Card. The exact terminals used vary depending upon whether three

or four wire topology is used, and the requirement for loop current source or sink

configuration. The Schematics below detail the connections for 3 wire current sink or source

transmitters. For other schematics (including isolated and barrier) refer to operating manual

05701-M-5001.