COMEM DTI Manual De Instrucciones página 5

DTI and eDTI
Connection of the temperature sensors
For the connection of the sensor RTD PT100 it's necessary to follow the indica-
tion of the wiring diagram of this manual: pay attention to not invert the position
between the conductors with red insulator and the conductor with white insulator.
The probes type PT100 with three wires use the third wire to compensate the
resistance of the conductors (max 20 Ω).
If the sensor has two wires (normally white and red) it's necessary to short-circuit
the terminals with the red wire (1-2, 4-5, 7-8, 10-11).
To reduce the external noises, it's necessary to use the following indication for
the wires:
• use probes with shielded wire connected at earth and wires twisted
• separate the wires of the probes from wires of power supply
• use wires with section at least of 0,5 mm
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• use wires with conductor with tin or silver-plated
Output relays
For the connection of the output contacts it's necessary to follow the indication
in the diagram.
The ALARM and TRIP relays commute when the threshold set value gets over.
The FAULT relay is normally energized, and it commutes in presence of a PT100
anomaly or of the device.
During the normal functioning of the device the contact 38-39 is open, while the
39-40 is closed.
The FAN relay is used to control the cooler fan, according to the on/off thresholds
set.
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