Thermo Fisher Scientific Alpha COND 1000 - Manual (Page 12)

Operating Instructions Thermo Scientific Alpha COND 1000
4
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.
ENSURE that the power cable is physically separated from the power
supply.
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
HOLD ALARM RELAY2
Pt1000
NC
- +
cell
J2