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NT935BH
The NT series equipment boasts an innovative control function combined with the dynamic status of the Pt100 sensor.
Activating FCD, the control unit analyses the increase in temperature ∆T (*) recorded in a second (
°C/sec
).
Enabling the function, the user can select the value (ΔT) from a minimum of 1°C/sec up to a maximum of 30°C/sec. If the
measured value is higher than the value set by the user, the control unit inhibits any activation of the ALARM and TRIP
alarms and activates the switching of the FAULT relay (11-12), signalling on the display
"fault for Fcd".
e.g. setting the function to 5°C, the fault switching for FCD will only be activated if the control unit detects an increase
ΔT
higher than 5°C in one second on the monitored system.
Setting "no" the FCD function is disabled.
When a channel is in Fault for FCD, the relative alarm and trip signals are inhibited on the single channel; therefore only
the anomaly of excessively rapid increase of the temperature is signalled.
Press Reset to cancel the FCD signals of all the channels and reset the relay fault.
Possible applications of FCD
Identification of a possible induced interference on the Pt100 sensor line
If the installation instructions are not complied with (see page 15), any interference on the Pt100 sensor line can cause
false readings or anomalous alarms.
Setting the FCD function in a temperature range of between 1°C and 10°C
(
5°C recommended), the effects caused by
false readings can be suppressed and the alarm relay activation can be prevented, as shown above.
Corrective actions: check the installation of the sensor extension cable is in line with the instructions given in the
paragraph on the measurement signal transfer on page 15.
Identification of a sensor fault or faulty connection
In case of a faulty connection or sensor fault, a quick positive or negative variation in temperature might occur, leading to
the system tripping or the alarms of the monitored system to be triggered.
In this specific case we recommend the FCD function to be set in a temperature range of between 10°C and 20°C.
Corrective actions: check the terminals the sensor is connected to are tightened and replace the faulty sensor, if required.
Identification of the electrical motor rotor block
In case of temperature control of the electrical motors, the quick temperature increase might be due to a blocked rotor.
In this specific case, it is advisable to set the FCD function in a temperature range of between 20°C and 30°C
.
This
setting is recommended in order to avoid activation of the FCD function during the motor starting phase, i.e. in the
presence of the increase
ΔT/sec.
has a very rapid variation.
(*)
The ΔT value shows the temperature range for each second.
NOTE: it is advisable not to enable the FCD function with VOTING active.
The purchased Product is covered by the manufacturer's or seller's warranty under the terms and conditions indicated in
the "Tecsystem s.r.l. General Sales Conditions", which can be consulted on the website www.tecsystem.it and/or in the
stipulated purchase contract.
The warranty is considered valid only when the product is damaged by causes attributable to TECSYSTEM srl, such as
manufacturing or components defects.
The warranty is invalid if the Product proves to have been tampered with/modified or incorrectly connected and causing
voltages outside the set limits and does not comply with the technical data for use and assembly, as described in this
instruction manual.
The warranty is always ex Corsico as stated in the "General Conditions of Sale".
FCD FUNCTION
WARRANTY REGULATIONS
