Instruction manual

11
3.2 Connection Diagram
Caution: Ensure electrical mains are disconnected before proceeding.
Connection for wall mounting version
RELA RELB WA SH RELAY ALARM RELAY
-+
Current
OP 2
29 28 19
GND +12V
-+
Current
OP1
3031 20
E
22
PT100/
PT1000
27
LIQ
GND
2524 26
HOLD
14 13
12
9
1011
87
N LE
3
4
21
56
pH/ mV
1. AC mains live wire 17. no connection
2. AC mains neutral wire 18. no connection
3. AC mains protective earth wire 19. 12V Power supply
4. Alarm relay (NO) 20. 12V ground
5. Alarm relay common 21. no connection
6. Alarm relay (NC) 22. Earth ground
7. Wash relay 23. no connection
8. Wash relay 24. Temperature ground
9. Relay B (SP 2) 25. Temperature input
10. Relay B (SP 2) 26. Temperature sense (short to
11. Relay A (SP 1) terminal 25 if using 2- wire RTD)
12. Relay A (SP 1) 27. PMP, liquid ground in symmetrical
m
ode
13. Hold function 28. 4-20 mA temperature output, -ve
terminal
14. Hold function 29. 4-20 mA temperature output, +ve
terminal
15. no connection 30. 4-20 mA pH output, -ve terminal
16. no connection 31. 4-20 mA pH output, +ve terminal
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).