Instruction manual

Operating Instructions αlpha-CON1000

68X216802

3.2 Back Panel

The back panel consists of two connectors. The first connector is the 17-way PCB edge connector and

the other is the 5-way connector.

Connection for the 17-way screw terminals (from left to right):

1. AC mains live wire 10. Alarm relay resting position (NO)

2. AC mains neutral wire 11. Alarm relay common

3. AC mains protective earth wire 12. Alarm relay working position (NC)

4. Low set relay resting position (NC) 13. Hold function switch terminal 1

5. Low set relay common 14. Hold function switch terminal 2

6. Low set relay working position (NO) 15. No connection

7. High set relay resting position (NC) 16. 0/4 - 20 mA for -ve connection

8. High set relay common 17. 0/4 - 20 mA for +ve connection

9. High set relay working position (NO)

Connections for the 5-way screw terminals:

18. Pt1000/Pt100 lead 1 terminal

19. Pt1000/Pt100 sense lead terminal

20. Pt1000/Pt100 lead 2 terminal

21. Conductivity lead 1

22. Conductivity lead 2

IMPORTANT: The Alarm relay functions as an “Active Low” device i.e. it switches OFF under

Alarm condition. Therefore the Alarm display device should be connected to the ‘NC’ contacts of

the relay.

Pt100/

RELAY1

L N PE

63mA

(F)

FUSE 250VAC

H O LD

ALARMRELAY2

Pt1000

N C

cell