ABB Comem DTI User manual

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TRANSFORMER COMPONENTS
Temperature monitoring device
Comem DTI and Comem eDTI
Instruction manual
Content
1. Safety
1.1 Safety instructions 3
1.2 Specified applications 4
1.3 Safety notes on the equipment operation 4
2. Comem DTI and eDTI 5
2.1 Operating principle 5
2.2 Installation 6
2.3 Connection of the temperature sensors 7
2.4 Output relays 7
3. Electrical diagram 8
4. Wiring connection 9
5. Front panel description 10

2TEMPERATURE MONITORING DEVICE COMEM DTI AND COMEM EDTI - INSTRUCTION MANUAL
6. Programming of the device 11
6.1 Selection of the HOLD function 11
6.2 Selection of the number of active inputs 12
6.3 Control ventilation 12
6.4 Selection of the threshold of switch on and switch off
ventilation 13
6.5 Selection of the alarm and trip threshold 13
6.6 Selection of address network identification for the
communication of the serial port (MODBUS-RTU protocol) 14
6.7 Selection of the baud rate 14
6.8 Selection data bit and stop bit 15
6.9 Selection of the linked channel with the analogue output 16
6.10 Configuration output signal 17
6.11 Configuration diagnostic probes 18
6.12 Exit from the programming phase 18
7. Modality of tripping and restore 19
7.1 Alarm 19
7.2 Trip 19
7.3 To silence alarm 19
8. Diagnostic 20
9. Visualization of the maximum measured temperature 21
10. Visualization of the channels with the higher temperature 22
11. Test of the light signaling 22
12. Exclusion of the input probes not used 22
13. Technical features 23
14. Dimensions 24
15. Movement, transport and storage 25
16. Appendix A: MODBUS address. 26

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1. Safety
1.1 Safety instructions
Make sure that any persons installing, taking into operation and
operating the “temperature monitoring device Comem DTI/eDTI”:
• Are technically qualified 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 emphasize important information.
THIS INFORMATION INDICATES PARTICU-
LAR DANGER TO LIFE AND HEALTH. DISRE-
GARDING SUCH A WARNING CAN LEAD TO
SERIOUS OR FATAL INJURY.
ALL RELEVANT FIRE PROTECTION REGULA-
TION MUST BE STRICTLY OBSERVED.
THIS INFORMATION INDICATES PARTICU-
LAR DANGER TO EQUIPMENT OR OTHER
PROPERTY OF THE USER. SERIOUS OR FA-
TAL INJURY CANNOT BE EXCLUDED.
THE TEMPERATURE CONTROL UNIT
COMEM 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 IN-
STRUCTION 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.
THESE NOTES GIVE IMPORTANT OR
SPECIFIC INFORMATION CONCERNING THE
EQUIPMENT OR AS TO WORK WITH THE
EQUIPMENT.
WARNING
WARNING
CAUTION
CAUTION
CAUTION
NOTE

4TEMPERATURE MONITORING DEVICE COMEM DTI AND COMEM EDTI - INSTRUCTION MANUAL
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1. Safety
1.2 Specified applications
The Temperature monitoring device Comem DTI/eDTI is used in
resin or dry type transformers and can also be easily adapted for
use in oil transformers. The Comem DTI/eDTI uses PT100
temperature probes for a constant monitoring of transformer
temperatures. The device generates two intervention levels of
electric signals (alarm and trip).
1.3 Safety notes on the equipment operation
The electrical installation must conform to the national safety
regulations.
The Temperature monitoring device Comem DTI/eDTI has double
insulation. Earthing is not required.
THE WIRES MUST BE FIXED PROPERLY
CAUTION

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TRANSFORMER COMPONENTS
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2. Comem DTI and eDTI
2.1 Operating principle
The Comem 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,
Comem DTI unit generates an alarm signal. If the temperature
reaches danger levels the unit generates a second intervention
level. Moreover, a switch can manage the fan.
Comem eDTI version has one port of serial communication RS485
which allows the connection of the measurement data, control
and programming of the device to acquisition system (PC, PLC,
SCADA, etc.). Modbus RTU is the protocol used (see specific
manual for instruction).
A Windows software is available for a management of the device
with complete function of control, storing data and recording
alarm. In addition, it is available an analogue settable output 0-20
mA or 4-20 mA with scale FROM -30°C to +200°C.
The devices type Comem DTI and Comem eDTI allow the control
and the visualization of temperature read with probe type RTD
PT100.
For each channel of measure are available two levels (alarm and
trip) that actives the commutation of the relative output relay for
signaling at distance or for disabling the machine under control.
In the front panel there are a double three-digit display that
shows the temperatures, the status of the alarm of the
measurement channels and five buttons for the programming.
The instrument can control the ventilation, storing maximum
values and trip alarms.

6TEMPERATURE MONITORING DEVICE COMEM DTI AND COMEM EDTI - INSTRUCTION MANUAL
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2. Comem DTI and eDTI
2.2 Installation
The Comem DTI family are devices which use PT100 temperature
probes for constant monitoring of transformer temperatures.
Read carefully the present manual before to install and to use the
device. 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

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TRANSFORMER COMPONENTS
2.3 Connection of the temperature sensors
For the connection of the sensor RTD PT100 it’s necessary to
follow the indication 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

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
2.4 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.

8TEMPERATURE MONITORING DEVICE COMEM DTI AND COMEM EDTI - INSTRUCTION MANUAL
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3. Electrical diagram

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TRANSFORMER COMPONENTS
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4. Wiring connection
View rear panel of the instrument with terminals for the connections

10 TEMPERATURE MONITORING DEVICE COMEM DTI AND COMEM EDTI - INSTRUCTION MANUAL
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5. Front panel description
1
2
3
4
8
910 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 confirm 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