4T1168
TECSYSTEM S.r.l ®
Channel CH2 must always be referred to the transformer central column.
If there are 3-wire PT100 sensors, we suggest to connect in common the 2 red conductors.
8) PROGRAMMED DATA DIAGNOSTIC
In case of breaking of the internal storage or corruption of the programmed data, just after
switching ON all the leds are blinking with the relevant reporting of the Fault contact.
In this case, for safety reasons, the default parameters Alarm Ch1-2-3= 90°C, Trip Ch1-2-
3= 120°C are automatically loaded.
To remove the fault condition, press RESET and run programming to insert once again the
desired values.
Finally turn off and turn on again the unit to verify the correct memory working; in case it is
damaged and the fault signallings still appears, please return the monitoring unit to Tecsys-
tem for repair.
9) TEMPERATURE DIAGNOSTIC
If one of the temperature sensor detects a temperature higher than 1°C compared to set L1
value, after approximately 5 seconds L1 relay switches together with the turning on of LED
L1 of the reference channel.
When the L2 temperature limit is passed, L2 relay switches together with the turning on of
LED L2 of the reference channel.
When the taken temperature returns to equal or lower values than the set limits, relays re-
turn in a no-alert condition with consequent turning off of relevant LED’s.
4) FLAT CABLE FOR CONNECTION WITH THE FRONT PANEL
T1168 monitoring unit has a flat cable connection to connect the motherboard with the front
panel mounted on the cover. It is possible to remove the flat cable to make easier the
mounting or maintenance operations; for relevant connections please follow the instructions
in the figure 1.
5) WORKING OF ALARM RELAY 1 (L1)
L1 relay normally works when the monitoring unit is fed and therefore the N.O. contact is
closed. When the loaded L1 alarm threshold is reached or when there is a damage in the
monitoring unit itself, the relay de-energizes with the consequent closure of N.C contact.
Besides, L1 relay shares the FAULT Pt100 sensor function; intervention of this relay, to-
gether with the BLINKING of Pt100 sensor FAULT LED, shows an error in the reading of a
Pt100 sensor as follows:
1) Open sensor (FOC): all the LED’s on the temperature scale are ON and the FAULT
LED is blinking.
2) Short-circuited sensor (FCC): the first led on the temperature scale (50 °C) is ON
and the FAULT LED is blinking.
To restore the Fault switching, it is necessary to verify the Pt100 connections and eventu-
ally replace the faulty sensor.
6) WORKING OF ALARM RELAY 2 (L2)
L2 relay is normally de-energized and therefore N.O contact is open. When the loaded L2
alarm threshold is reached, it energizes and therefore the N.O. contact gets closed.
7) TEMPERATURE SENSOR CONNECTION
Each temperature sensor Pt100 has a white and a red wire.
Figure. 2 shows the position inside the terminal box of monitoring unit connection cable.
