Innotech Genesis V4 System - Manual (Page 102)

Installation Instructions for Innotech Genesis Systems
Edition 011100
A-21
Figure A-20 shows the same arrangement as that shown in Figure A-19 but with the screen
earthed in Control Panel No. 1 and GENII 485I cards fitted to all other Digital Controllers.
This provides the same degree of isolation but is more expensive because three isolator
cards are needed. All Digital Controllers remote from the point where the screen is earthed
must be fitted with GENII 485I cards. This does not remove the hazard of the earth voltage
in Control Panel No. 1 being present on the screen of the Comms cable in Control Panel
No. 2.
Figure A-20. Use of GENII 485I Card, Circuit 2.
Switchboard or
Control Panel No. 2
Switchboard or
Control Panel No. 1
Screen 1 2
Connect Screen
Isolated
RS485
GEN485I Card
isolates Digital
Controller from
cable.
Screen 1 2
Connect Screen
Isolated
RS485
GEN485I Card
isolates Digital
Controller from
cable.
Screen 1 2
Connect Screen
Isolated
RS485
GEN485I Card
isolates Digital
Controller from
cable.
Screen 1 2
Connect Screen
Six outer links
fitted. Screen is
earthed via
Terminal 2.