10
••
••
• Power Supply: Connect a 3-wire power cable
to the terminal strip, while paying attention
to the correct live (L), earth (PE) and neu-
tral (N) terminal connections.
Power: 115VAC -100 mA / 230VAC - 50 mA.
Live Contact: fused inside 200mA.
PE leakage current 1 mA; this contact must be con-
nected to ground.
••
••
• Conductivity input: the default input is from conductivity
probe. Connect the EC probe to the terminals #9 on page
7. Connect the cable shield to pin 1, and the other four
wires according to the following table:
Color Pin #
GREEN 2
WHITE 3
RED 4
BLUE 5
••
••
• Pt 100 Terminals: these contacts (#8 on page 7) connect
the Pt 100 temperature sensor for automatic temperature
compensation of measurement. The HI7639 EC/TDS probe
has a built-in 3-wire Pt 100 sensor to be connected ac-
cording to the following table:
Color Pin #
GRAY 6
BROWN 7
YELLOW 8.
If using a different Pt 100, connect it as explained below.
In the case of a 2-wire sensor connect
the Pt 100 to pins 1 and 3, and short
pins 2 and 3 with a jumper wire.
If the Pt 100 has more than 2 wires, con-
nect the two wires of one end to pins 2
and 3 (pin 2 is an auxiliary input to com-
pensate for the cable resistance) and one
wire from the other end to pin 1. Leave
the fourth wire unconnected, if present.
