Thermo Fisher Scientific Alpha pH 800 - Manual (Page 14)

7
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.No connection
2.AC mains neutral wire 11.No connection
3.AC mains protective earth wire 12.No connection
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) 16.4 - 20 mA for -ve connection
8.High set relay common 17.4 - 20 mA for +ve connection
9.High set relay working position (NO)
Connections for the 5-way screw terminals:
18. Pt100/Pt1000 lead 1 terminal
19. Pt100/Pt1000 sense lead terminal
20. Pt100/Pt1000 lead 2 terminal
Note: If using a two-wire RTD, short terminal 19 to terminal 18.
Pt 100/Pt 1000 is selectable via an internal jumper. Factory default is Pt100. See
Appendix 1 for directions on switching the RTD type.
21. pH/ORP (potential matching pin)
21. pH/ORP (shield)