Thermo Fisher Scientific Alpha DO 1000 User Manual
Page 12

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):
Pin No
Description
Pin No
Description
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 (please refer to DO probe wiring
instruction manual):
Pin No
Description
DO Probe Wiring Colour
18
Pt100 lead 1
White
19
Pt100 sense lead
Red
20
Pt100 lead 2
Black
21
Cathode, –ve connection
Green
22
Anode, +ve connection
Yellow