COMEM DTI User manual

Temperature monitoring unit
DTI and eDTI
Instruction manual
TRANSFORMER COMPONENTS

TEMPERATURE MONITORING UNIT DTI AND EDTI
2
Content index
Safety ........................................................... 3
DTI and eDTI ................................................. 4
Electrical diagram......................................... 6
Front panel description................................. 7
Programming of the device .......................... 8
Modality of tripping and restore ................. 14
Diagnostic .................................................. 15
Visualization of the maximum
measured temperature............................... 16
Visualization of the channels with
the higher temperature............................... 16
Test of the light signaling ........................... 16
Exclusion of the input probes
not used...................................................... 16
Technical features...................................... 17
Movement, transport and storage .............. 17
Appendix A: MODBUS address................... 78
Dimensions................................................. 79
Content index
Sicurezza ................................................... 18
DTI / eDTI.................................................... 19
Schema elettrico ........................................ 21
Vista frontale dell’apparecchio................... 22
Programmazione del dispositivo................ 23
Segnali di allarme e riarmo......................... 29
Auto-diagnostica ........................................ 30
Visualizzazione della temperatura
massima..................................................... 31
Visualizzazione dei canali con la
temperatura maggiore................................ 31
Prova delle spie LED................................... 31
Estromissione degli ingressi PT100 non
utilizzati ..................................................... 31
Caratteristiche tecniche ............................. 32
Stoccaggio.................................................. 32
Appendce A: MODBUS address.................. 78
Dimensioni.................................................. 79
Inhalt
Sicherheit ................................................... 33
DTI und eDTI............................................... 34
Schaltplan................................................... 36
Beschreibung des Frontpanels................... 37
Programmierung der Einheit....................... 38
Abschalt- und Reset-Modus ....................... 44
Fehlersuche................................................ 45
Anzeige der gemessenen
Höchsttemperatur ...................................... 46
Anzeige der Kanäle mit der höheren
Temperatur................................................. 46
Testen der Warnleuchten............................ 46
Ausschließen der nicht genutzten
Fühlereingänge........................................... 46
Technische Merkmale ................................ 47
Heben, Transport und Lagerung ................. 47
Anhang A: MODBUS-Adresse..................... 78
Abmessungen............................................. 79
Índice de contenidos
Seguridad ................................................... 48
DTI y eDTI ................................................... 49
Diagrama eléctrico ..................................... 51
Descripción del panel frontal...................... 52
Programación del dispositivo..................... 53
Modalidad de disparo y restauración ......... 59
Diagnóstico ................................................ 60
Visualización de la temperatura máxima
medida........................................................ 61
Visualización de los canales con la
temperatura más alta ................................. 61
Prueba de la señalización luminosa........... 61
Exclusión de las sondas de entrada
no utilizadas ............................................... 61
Características técnicas............................. 62
Movimiento, transporte y
almacenamiento......................................... 62
Apéndice A: Dirección MODBUS................. 78
Dimensiones............................................... 79
Index du contenu
Sécurité ...................................................... 63
DTI et eDTI.................................................. 64
Schéma électrique...................................... 66
Description du panneau avant.................... 67
Programmation de l’appareil ...................... 68
Modalité de déclenchement et de
restauration ................................................ 74
Diagnostic .................................................. 75
Visualisation de la température
maximale mesurée ..................................... 76
Visualisation des canaux avec
la température plus élevée ......................... 76
Test de la signalisation lumineuse ............. 76
Exclusion des sondes d’entrée
non utilisées ............................................... 76
Caractéristiques techniques....................... 77
Mouvement, transport et stockage............. 77
Annexe A: Adresse MODBUS ..................... 78
Dimensions................................................. 79

3
Safety
Safety instructions
Make sure that any person installing, taking into operation and operating the
“temperature monitoring unit DTI/eDTI”:
• is technically qualied and competent.
• fully comply with these assembling instructions.
Improper operations or misuse could cause danger to:
• life and limb
• to the equipment and other assets of the operator
• to the equipment proper function
Opening of the device will void your warranty.
Safety instructions in this manual are shown in three different forms to emphasi-
ze important information.
This information indicates particular
danger to life and health. Disregarding such
a warning can lead to serious or fatal injury.
This information indicates particular
danger to equipment or other property of
the user. Serious or fatal injury cannot be
excluded.
The temperature control unit DTI/eDTI
must not be installed near sources of
electromagnetic interference.
Installation, electrical connection and
fitting the device may only be carried out by
qualified personnel and only in accordance
to this instruction manual.
It is responsibility of the user to make
sure that the device is used for specified
application only.
For safety matters, please avoid any
unauthorized and improperly works.
All relevant fire protection regulation must
be strictly observed.
These notes give important or specific
information concerning the equipment or
as to work with the equipment.
WARNING CAUTION
CAUTION
CAUTION
WARNING
NOTE

4
DTI and eDTI
Product description
The Temperature monitoring device DTI/eDTI is used in resin or dry type transfor-
mers and can also be easily adapted for use in oil transformers.
The DTI/eDTI uses PT100 temperature probes for a constant monitoring of tran-
sformer temperatures. The device generates two intervention levels of electric
signals (alarm and trip).
Safety notes on the equipment operation
The electrical installation must conform to the national safety regulations.
The Temperature monitoring device DTI/eDTI has double insulation. Earthing is
not required.
The DTI family are devices which use PT100 temperature probes for constant
monitoring of transformer temperatures in 4 points: three on the transformer
winding columns and one on the machine’s magnetic circuit.
If the transformer malfunctions, causing its temperature to rise, DTI unit genera-
tes an alarm signal. If the temperature reaches danger levels the unit generates a
second intervention level. Moreover, a switch can manage the fan.
Installation
The device must be installed and used by personal opportunely learned.
Before to proceed at the installation it’s necessary to verify if the device is intact
and it hasn’t damages due to transportation or handling. The power supply must
be compatible with the device range. The instrument installation must be done in
total absence of voltage and observing the security norm in force.
All operation of maintenance and reparation executed by not authorized persons
are forbidden.
If during the functioning the device becomes unsafe, it’s necessary to put it out of
action and to be sure that this device won’t be used unintentionally.
The use shall be considered unsafe when the instrument:
• doesn’t work regularly
• has damage clearly visible
• has damage caused of transport or handling
• is stored in bad condition
The wires must be fixed properly
CAUTION
TEMPERATURE MONITORING UNIT DTI AND EDTI

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 mm2
• 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.

6
Electrical diagram
View rear panel of the instrument with terminals for the connections
TEMPERATURE MONITORING UNIT DTI AND EDTI

7
°C
T3 T4
123 4
FAULT
HOLD
FAN
SET
ALARM
TRIP
T1 T2
HOT
T.
MAX ENTER
RESET
°C
eDTI
Modbus RTU / 4-20mA
°C
T3 T4
123 4
FAULT
HOLD
FAN
SET
ALARM
TRIP
T1 T2
HOT
T.
MAX ENTER
RESET
°C
DTI
°C
T3 T4
123 4
FAULT
HOLD
FAN
SET
ALARM
TRIP
T1 T2
HOT
T.
MAX ENTER
RESET
°C
DTI
033048
°C
T3 T4
123 4
FAULT
HOLD
FAN
SET
ALARM
TRIP
T1 T2
HOT
T.
MAX ENTER
RESET
°C
eDTI
Modbus RTU / 4-20mA
033048
Front panel description
1
2
3
4
8
9 10 10
11
7
6
5
Legend:
1. LEDs T1-T2-T3-T4 for the on-measuring channel displayed
2. T1-T2 and T3-T4 displays for the channel temperature visualization and
settings
3. LEDs ALARM for the Alarm status in the related channels (1 to 4)
4. LEDs TRIP for the Trip status in the related channels (1 to 4)
5. LED FAULT: failure indication (device or PT100 probes)
6. LED HOLD: the manual reset is active
7. LED FAN: the ventilation output is active
8. Push - button HOT / T. MAX to display the measured channel with higher
temperature (LED indication activated) and to display maximum
temperatures achieved
9. Push - button ENTER / RESET to conrm programming set and the manual
alarm reset intervention
10. Push - buttons →+ / ←-for selecting the displayed channel and for changing
parameter of programming
11. Push - button SET for the settings

8
Programming of the device
When the device is switched on, on the display will ash the index of the internal
software: later the device starts to display the temperature read on the measured
input.
To enter in the programming mode, press the button SET for some second up to
light the relative SET LED.
The settings appear in the sequence showed after. To go out of the programming
mode without changing the preset values, it’s necessary to press SET without
conrming with the ENTER key the modied data.
To modify the values or the status, it’s necessary to use →and ←keys and the
ENTER key to store the modication.
The pressure of the ENTER key move automatically the programming at the
successive function or value.
Selection of the HOLD function
This is the rst function in the set menu. In this programming phase the HOLD
LED switches on.
The Hold function allows to store the alarm condition that can be rearmed only
manually with the RESET button when the temperature is lower than the threshold
set.
If this function is disabled it’s possible to rearm the ALARM with the RESET
button even if the temperature is higher than the threshold set, while the value of
temperature come back under the threshold set the alarm will be automatically
deleted.
To set the Hold function it’s necessary to use the ←and →keys:
ON function enabled
OFF function disabled
Press the ENTER key to conrm the operation.
HOLD mode T1-T2 display T3-T4 display
HOLD mode activated HLD Off
TEMPERATURE MONITORING UNIT DTI AND EDTI

9
Selection of the number of active inputs
It is possible to select the number of activated inputs. It’s possible to choose
between 3 and 4 inputs enabled; if there are 3 inputs enabled the T4 display
remain off.
Select 3 or 4 inputs with ←and → keys.
Conrm with ENTER.
Control ventilation
The FAN led will switch on indicating the programming of the ventilation control.
If 3 inputs are selected the following setting are available:
• ventilation control inhibited
• fan control active on 3 inputs
Select the conguration with ←and → keys.
Conrm with ENTER.
If 4 inputs are selected the following setting are available:
• ventilation control inhibited
• fan control active on 3 inputs
• control active only on fourth input
Select the conguration with ←and → keys.
Conrm with ENTER.
Programming of the device
Active inputs mode T1-T2 display T3-T4 display
3 inputs activated Ch 123
All inputs activated Ch ALL
Fan mode (3 inputs) T1-T2 display T3-T4 display
Fan control inhibited FAN Off
Fan control on 3 inputs FAN ON
Fan mode (3 inputs) T1-T2 display T3-T4 display
Fan control inhibited FAN Off
Fan control on 3 inputs FAN ON
Fan control on 4 inputs FAN 4

10
Programming of the device
Selection of the threshold of switch-on and switch-off ventilation
It is possible to program the threshold for enabling and disabling the ventilation.
• Selection the threshold for disabling ventilation
The FAN LED is on, with xed light indicates this phase of programming.
With ←and → keys select the value of temperature indicated on display.
Interval of programming: from -25°C up to (enabling threshold -1°C)
Conrm with ENTER.
• Selection the threshold for enabling ventilation
The FAN LED is on, with ashing light indicates this phase of programming.
With ←and → keys select the value of temperature indicated on display.
Interval of programming: from (disabling threshold +1°C) up to 200°C
Conrm with ENTER.
Selection of the alarm and trip threshold
This setting starts to program from the channel number 1.
The ALARM LED ON indicates the programming of the alarm:
With ←and →keys select the value of temperature
Interval of programming: from -25°C up to (trip threshold -1°C)
Conrm with ENTER.
The TRIP LED ON indicates the programming phase of the tripping threshold.
With ←and →keys select the value of temperature
Interval of programming: from (alarm threshold +1°C) up to 200°C.
Conrm with ENTER.
Repeat the same operation for the successive channels.
Selection of address network identication for the communication of the serial
port (MODBUS-RTU protocol)
This setting is indicated on displays with:
• value to set on T1-T2 display
• ID on T3-T4 display.
With ←and →keys select the number choice
The range for accepted value is from 1 to 247.
Conrm with ENTER.
This setting is significant only for eDTI model.
NOTE
Modbus setting T1-T2 display T3-T4 display
Setting address MODBUS network 001 ID
TEMPERATURE MONITORING UNIT DTI AND EDTI

11
Selection of the baud rate
This setting is indicated on displays with:
• BDR on T1-T2 display
• value to set on T3-T4 display.
With ←and →keys select the baud rate
It’s possible to choose between the following values: 2,4 - 4,8 - 9,6 - 19,2 kbps.
Conrm with ENTER.
Selection data bit and stop bit
This setting is indicated on displays with:
• the type of parity on T1-T2 display
• the number of data bit and stop bit on T3-T4 display.
With ←and → keys select the options.
Conrm with ENTER.
Programming of the device
This setting is significant only for eDTI model.
This setting is significant only for eDTI model.
NOTE
NOTE
Data-stop bit setting T1-T2 display T3-T4 display
No parity / 8 data bit - 1 stop bit NO 8-1
No parity / 8 data bit - 2 stop bit NO 8-2
Even parity / 8 data bit - 1 stop bit EVE 8-1
Odd parity / 8 data bit - 1 stop bit ODD 8-1
Baud rate setting T1-T2 display T3-T4 display
Baud rate: 19200 BDR 19.2
Baud rate: 9600 BDR 9.6
Baud rate: 4800 BDR 4.8
Baud rate: 2400 BDR 2.4

12
Selection of the linked channel with the analogue output
This setting is indicated on displays with:
• AN on T1-T2 display
• the linked measure channel on T3-T4 display: CH 1/2/3/4 for the 1/2/3/4
measure channel, ALL to link the measure channel with the higher temperature.
With ←and → keys to select the options.
Conrm with ENTER.
Conguration output signal
In this phase it’s possible to dene the type of signal of analogue output as 0-20
mA or 4-20 mA.
This setting is indicated on displays with:
AN0 -20 to set the output as 0-20mA or (0 mA = -30°C; 20 mA = 200°C)
AN4 -20 to set the output as 4-20 mA or (4 mA = -30°C; 20 mA = 200°C)
With ←and → keys select the options.
Conrm with ENTER.
Programming of the device
This setting is significant only for eDTI model.
This setting is significant only for eDTI model.
The maximum load for analogue output
is 400 Ω.
NOTE
NOTE NOTE
Link channel setting T1-T2 display T3-T4 display
Channel with higher temperature AN ALL
Measure channel CH 1 AN Ch 1
Measure channel CH 2 AN Ch 2
Measure channel CH 3 AN Ch 3
Measure channel CH 4 AN Ch 4
Analogue signal setting T1-T2 display T3-T4 display
Output proportional 0 - 20 mA AN 0 -20
Output proportional 4 - 20 mA AN 4 -20
TEMPERATURE MONITORING UNIT DTI AND EDTI

13
Programming of the device
Conguration diagnostic probes
This function allows to enable or to disable the control on the probes. This fun-
ctionality controls the variation of the temperature in a dened time. A ag raise
if this variation is higher than a set value.
Exit from the programming phase
Press the SET key or wait for about 8 seconds without to press any key to come
out of the programming phase.
It’s necessary to indicate the maximum variation temperature:
• FDC: min 5°C or max 30°C
and after the time in which to do the control:
• FDC: min 10” or max 90” (time in seconds)
The →+ key is used to increase the values while the ←- key to decrease.
Conrm with ENTER.
FDC setting T1-T2 display T3-T4 display
FDC mode disabled FDC Off
FDC mode enabled FDC ON
Temperature conguration FDC T1-T2 display T3-T4 display
Min °C FDC -5°
Max °C FDC 30°
Time conguration FDC T1-T2 display T3-T4 display
Min in seconds FDC 10’’
Max in seconds FDC 90’’

14
Modality of tripping and restore
Alarm
On the relative channel, if the threshold value set is exceeded of +1°C, after 5
seconds the ALARM relay is energized and the ALARM led is.
The alarm rearm (relay de-energized and the involved LED off) occurs when the
temperature goes down of 2°C respect at the threshold value set.
Trip
On the relative channel, if the threshold value set is exceeded of +1°, after 5
seconds the TRIP relay is energized and the TRIP led is.
The trip rearm (relay de-energized and the involved LED off) occurs when the
temperature goes down of 2°C respect at the threshold value set.
To silence alarm
If the Hold function is disabled, it’s possible to silence the alarm condition. During
the alarm condition the ALARM relay and the “ALARM” optical signalling are
enabled.
Pressing the Reset button, the relay will be de-energized while the optical signal-
ling of the alarm condition becomes ash.
If the temperature increases up to reach the (TRIP temperature - 1°C), the relay
and the optical signalling are enabled another time.
If after the reset, the temperature goes down under the threshold value set, the
ashing optical signalling will be automatically deleted.
TEMPERATURE MONITORING UNIT DTI AND EDTI

15
Diagnostic
The device is provided of the thermic probes diagnostic function.
The condition controlled on the measured input are:
• Probe PT100 interrupted: signalling on the display the message O P E (open).
• Probe in short circuit: signalling on the display the message S H R
(short circuit).
• Probe out of order for wrong read temperature: signalling on the display the
message F D C.
When the device switches on the auto-diagnostic, FAULT relay commutes and
it remains in the energized status until one of the above-described conditions
appears, or if a device failure occurs, or if the power supply is absent.
The anomaly conditions are signalled also by the FAULT led on.
Every time that a probe is out of order because it is interrupted (OPE) or in short
circuit (SHR) or the delta of temperature is too elevated (FDC), the corresponding
channel LED ashes until the anomaly stop.
The alarm of short circuited probe (SHR) or open probe (OPE) will be reset
automatically while the alarm for the delta of temperature (FDC) disappears by
pressing this sequence:
• push the ENTER key
• keep it pressed
• press the →+ key at least for 5 seconds.
The status of the relay contact (all available with exchange contact) is showed in
the following table:
RELAY DISABLE STATUS ENABLE STATUS UNPOWERED STATUS
ALARM OFF: closed 29-30 ON: closed 29-31 closed 29-30
TRIP OFF: closed 32-34 ON: closed 32-33 closed 32-33
FAN OFF: closed 35-36 ON: closed 35-37 closed 35-36
FAU LT OFF: closed 38-40 ON: closed 38-39 closed 38-40

16
Visualization of the channels with the higher temperature
Test of the light signaling
Exclusion of the input probes not used
Visualization of the maximum measured temperature
Pressing the HOT key for some seconds till switching to the HOT led.
On the T1-T2 display, the hotter temperature among the inputs 1 and 2 will
appear.
On the T3-T4 display, the hotter temperature among the inputs 3 and 4 will
appear.
To come back in the standard visualization mode, press the HOT key for some
second up to switch-off the relative signalling led.
Press at the same time ←and → keys: all the signalling lights will start to ash
for some seconds.
If one or more inputs are not used, it’s necessary to connect a resistance of value
included between 100 and 200 Ω, or 0.25W.
The input 4 can be disables through the “Selection number of active inputs” on
page 5.
In the gure is showed the connection to disable the input Ch1.
The same connection can be used for the other inputs.
Pressing the Tmax key on displays, it will appear - in ashing mode - the maximum
measured value of temperature.
To pass from the visualization of the maximum temperature T1-T3 to T2-T4 to use
←and → keys.
After 8 seconds the device come back to display the value of measured temperatures.
To reset the value of the maximum temperatures, go in the visualization maximum
values and press at the same time Tmax and ←.
01 02 03
R
Ch1
R = 100 120 Ω
0.25W
TEMPERATURE MONITORING UNIT DTI AND EDTI

17
Technical features
Storage
Auxiliary power supply 24/230 V dc/ac ±15% 50-60 Hz
Maximum consumption 4 VA
Measured inputs 3 - 4 inputs by RTD PT100 (max wire resistance 20 Ω)
Interval of measure -30°C up to +200°C / precision ± 2°C
Interval of visualization -30°C up to +220°C
Tripped delay-hysteresis 5 seconds – 2°C
Measured visualization 2 displays with led 7 segments, 3-digits
Outputs DTI: 4 relay NO-C-NC (250 V 5 A resistive load)
eDTI: 4 relay NO-C-NC (250 V 5 A resistive load),
0-20 mA or 4-20 mA (Default); Modbus RTU
Output functions alarm, trip, fan, auto-diagnostic
programmable functions ALARM, TRIP, HOLD, FAN, T.MAX, HOT, FDC
Connection Extractible terminal with screws, section wires max 2.5 mm2
Insulation 2500 Vrms 50 Hz per 60 s :U aux - input PT100 /
U aux - relay outputs / inputs PT100 - relay outputs
Protection degree IP52 front panel, IP20 rear panel, as CEI-EN 60529
Dimensions - enclosure Flash mounting DIN 96x96 mm, depth 120 mm /
Enclosure thermoplastic self-extinguishing as UL94 V0
Working temperature -10°C up to +60°C, humidity max 95%
Storing temperature -25°C up to +70°C
Standards Security: EN 61010-1
EMC: EN 61000-4-2; EN 61000-4-3; EN 61000-4-4;
EN 61000-4-5; EN 61000-4-11; EN 61000-6-4
Management software for eDTI Contact us at: [email protected]
The DTI/eDTI temperature monitoring devices are shipped inside a cardboard box
to facilitate transport and storage. As soon as the temperature monitoring device
DTI is received, the customer must perform the following operations:
• examine the outer packaging surface to be sure that it is intact
• check that there are no breakages
If damage is found, please contact COMEM and provide the shipping data
together with the serial number of the unit.
The temperature monitoring device DTI/eDTI must be stored in a dry place at
temperatures as indicated above.

18
Sicurezza
Istruzioni di sicurezza
Assicurarsi che il personale incaricato di installare e operare sul rilevatore di
temperatura “DTI/eDTI”:
• sia tecnicamente qualicator e competente.
• rispetti pedissequamente queste istruzioni d’assemblaggio.
L’uso improprio di questi dispositive potrebbe determinare un pericolo per:
• vita e arti
• attrezzatura e altri beni dell’operatore
• corretto funzionamento dell’attrezzatura
L’apertura del dispositivo comporta la perdita della garanzia.
Le istruzioni di sicurezza di questo manuale sono riportate in tre diversi formati
per sottolineare informazioni importanti.
Questa informazione indica un particolare
pericolo per la vita e la salute. Ignorare
questo tipo di avvertimento potrebbe
causare ferite gravi o fatali.
Questa informazione indica un particolare
pericolo per l’attrezzatura o altri beni
dell’operatore. Ferite gravi o fatali non sono
da escludersi.
Il rilevatore di temperatura DTI/eDTI non
deve essere installato in prossimità
di luoghi che presentano interferenze
elettromagnetiche.
L'installazione, la connessione elettrica
e il montaggio del dispositivo dev'essere
effettuato da personale qualificato e solo
secondo questo manuale di istruzione. È
responsabilità dell'utente assicurarsi che il
dispositivo sia utilizzato per la sua corretta
applicazione. Per questioni di sicurezza,
evitare usi non autorizzati o impropri.
Il regolamento antincendio deve essere
rigorosamente rispettato.
Questa nota offre informazioni importanti o
specifiche sull’apparecchiatura o su come
operarvi.
AVVERTIMENTO ATTENZIONE
ATTENZIONE
ATTENZIONE
AVVERTIMENTO
NOTA
RILEVATORE DI TEMPERATURA DTI / EDTI

19
DTI / eDTI
Descrizione del prodotto
Il rilevatore di temperatura DTI/eDTI (detto anche ‘centralina DTI/eDTI’) viene prin-
cipalmente utilizzato nei trasformatori a secco o in resina ma può essere anche
installato in presenza di trasformatori in olio.
La centralina DTI permette un monitoraggio continuo delle temperature nella
macchina tramite l’utilizzo di sonde PT100. Il dispositivo può generare due soglie
di intervento (allarme e sgancio).
Istruzioni di sicurezza sull’esercizio dell’apparecchio
Il regolamento nazionale di riferimento deve essere rispettato per quanto riguar-
da l’installazione elettrica.
La centralina DTI è a doppio isolamento e non richiede pertanto la connessione
di messa a terra.
La famiglia di prodotti DTI consiste in dispositivi che, tramite sonde PT100,
monitora le temperature del trasformatore in 4 punti chiave: tre nelle colonne
dell’avvolgimento ed uno nel circuito magnetico di macchina.
In caso di guasto la temperatura del trasformatore cresce, facendo scattare una
soglia di allarme nella DTI. Se la temperatura cresce ulteriormente, raggiungendo
livelli pericolosi, il secondo livello di intervento (sgancio) viene attivato.
Nella DTI è disponibile inoltre un contatto per gestire la ventilazione di macchina.
Installazione
Il dispositivo deve essere installato e utilizzato da personale addestrato.
Prima di procedere all’installazione è necessario vericare l’integrità e l’assenza
di danni sull’apparecchio. L’alimentazione deve essere compatibile con i valori
prescritti in questo manuale. L’installazione deve essere eseguita fuori tensione e
in accordo alle normative vigenti in materia di apparecchiature elettriche.
Non sono permesse attività di riparazione e manutenzione operate da personale
non autorizzato.
Nel caso in cui il dispositivo operi in maniera non sicura, sarà necessario discon-
netterlo e assicurarsi che non venga riattivato no alla necessaria verica.
La centralina opera in maniera non sicura quando:
• l’esercizio non è regolare
• vi sono dei danni evidenti
• lo stoccaggio non è stato effettuato correttamente
Il cablaggio deve essere eseguito con cura.
ATTENZIONE

20
DTI / eDTI
Collegamento delle sonde di temperatura
Per il collegamento delle sonde RTD (“Resistance Temperature Detector” ovvero
“rilevatore di temperatura a resistenza”) PT100 è necessario seguire gli schemi
elettrici presenti in questo manuale: fare attenzione alla giusta disposizione dei
cavi bianchi e rossi. Le sonde PT100 del tipo a tre li utilizzano per l’appunto tre
cavi per compensare la resistenza dei conduttori (max 20 Ω).
Se il sensore PT100 ha invece due cavi (generalmente bianco e rosso) è necessa-
rio corto circuitare i terminali ‘rossi’ (1-2, 4-5, 7-8, 10-11).
Per ridurre i disturbi esterni, è necessario:
• utilizzare sensori con li schermati a massa e intrecciati
• identicare e dividere i cavi di segnale (PT100) da quelli d’alimentazione
• utilizzare cavi con una sezione minima di 0,5 mm2
• utilizzare li con conduttori argentati o stagnati.
Relè di uscita
Per il collegamento dei contatti di uscita è necessario seguire le prescrizioni dello
schema elettrico di questo manuale.
ALARM (ALLARME) e TRIP (SGANCIO) commutano quando il valore di soglia
viene superato. Il relè FAULT (GUASTO) è attivo durante l’esercizio, e commuta
quando vi è un guasto su un sensore PT100 o un anomalia generale dell’appa-
recchio.
Durante il normale funzionamento quindi 38-39 è aperto mentre 39-40 è chiuso.
Il relè FAN (VENTILAZIONE) è utilizzato per controllare le ventole di raffredda-
mento, a seconda delle soglie di attivazione impostate.
RILEVATORE DI TEMPERATURA DTI / EDTI