Thermo Scientific ALPHA PH 2000 Manual page 20

Connection for panel mounting version
1. AC mains live wire
2. AC mains neutral wire
3. AC mains protective earth wire
4. Alarm relay (NO)
5. Alarm relay common
6. Alarm relay (NC)
7. Wash relay
8. Wash relay
9. Relay B (SP 2)
10. Relay B (SP 2)
11. Relay A (SP 1)
12. Relay A (SP 1)
13. Hold function
14. Hold function
15. no connection
16. no connection
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 (5 & 6).
NOTE:
Switch or circuit breaker shall included in the building installation.
It shall be in close proximity to the equipment and within easy reach of the
operator.
It shall be marked as the disconnecting device for the equipment.
17. no connection
18. no connection
19. 12V Power supply
20. 12V ground
21. no connection
22. Earth ground
23. no connection
24. Temperature ground
25. Temperature input
26. Temperature sense (short to terminal 25 if
using 2- wire RTD
27. PMP, liquid ground in symmetrical mode
28. 4-20 mA temperature output, -ve terminal
29 4-20 mA temperature output, +ve terminal
30. 4-20 mA pH output, -ve terminal
31. 4-20 mA pH output, +ve terminal