Installation - Hanna Instruments HI 720 Instruction Manual

INSTALLATION

Mechanical Dimensions
Electrical Connections
• Power Input: connect a 3-wire power cable to the line (L), earth
(PE) and neutral (N) terminal connections.
Power: 100 Vac-120 mA / 115 Vac-100 mA / 230 Vac-50 mA.
Line Contact: 400 mA fuse inside.
PE must be connected to ground; leakage current 1 mA.
• Probe Connections (#1 at page 9): connect the Tx and Rx coaxial cables to
the relevant terminals, as indicated. Connect the probe cable shield to the
"Shield" terminal.
• Pt100/Pt1000 Terminals (#2 at page 9): these contacts connect the Pt100/
Pt1000 sensor for automatic temperature compensation.
If the conductivity probe features a built-in Pt100/Pt1000 sensor, connect the
related wires to pins 1, 2 and 3; pin 4 will not be used.
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It is also possible to use a separate Pt100/Pt1000 temperature probe.
case of shielded wire, connect the shield to pin 4. In the case of a 2-wire
sensor connect the Pt100/Pt1000 to pins 1 and 3, and short pins 2 and 3
with a jumper wire.
If the Pt100/Pt1000 probe has more than 2 wires, connect the two wires of
one end to pins 2 and 3 (pin 2 is an auxiliary input to compensate for the
cable resistance) and one wire from the other end to pin 1. Leave the fourth
wire unconnected, if present.
Note The instrument automatically recognizes the sensor type (Pt100 or
Pt1000).
• Analog Outputs: when using shielded cable, if the shield is not connected at
the other end of the cable, then connect it to the "+" terminal, otherwise
leave it floating.
Note All cables connected to rear panel should end with cable lugs.
Note A circuit breaker (rated 10 A max.) must be connected in close prox-
imity to the equipment, and in a position easy to reach by the opera-
tor, for disconnection of the instrument and all devices connected to
the relays.
In the
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