INSTRUCTION MANUAL
Oil Temperature Indicator type “OTI / eOTI”
Winding Temperature Indicator type “WTI / eWTI”
5COW423700 – REV_E
I
II
CONTENTS
1.
SAFETY...................................................................................................................... 1
1.1 Safety instructions....................................................................................................... 1
1.2 Specified applications ................................................................................................. 1
1.3 Safety notes on the equipment operation ................................................................... 1
2.
DRAWING .................................................................................................................. 2
2.1 OTI/WTI/eOTI/eWTI .................................................................................................... 2
2.2 Bulbs ........................................................................................................................... 4
3.
OPERATING PRINCIPLE .......................................................................................... 5
3.1 Oil temperature indicator (OTI) – Oil temperature indicator with digital and analog
output (eOTI) .................................................................................................................... 5
3.2 Winding Temperature Indicator (WTI) – Winding Temperature Indicator with digital
and analog output (eWTI) ................................................................................................. 5
3.3 Outputs ....................................................................................................................... 6
3.4 Technical features....................................................................................................... 6
3.5 Tests ........................................................................................................................... 7
4.
INSTALLATION.......................................................................................................... 8
4.1 Flange connection....................................................................................................... 8
4.1 Elastic Suspension (optional) ...................................................................................... 8
5.
ELECTRICAL CONNECTION .................................................................................... 9
5.1 Wiring diagrams .......................................................................................................... 9
5.1.1 OTI – eOTI (2 , 4 contacts) ................................................................................... 9
5.1.2 WTI – eWTI (2 , 4 contacts) ................................................................................. 9
5.1.3 Pt100 .................................................................................................................... 9
5.2 Micro switches and PT100 (optional) ........................................................................ 10
5.2.1 Setting ................................................................................................................. 10
5.3 ΔT calibration for thermal Image (WTI / eWTI).......................................................... 11
5.4 eOTI/eWTI adding terminals ..................................................................................... 11
6.
OPERATION AND MAINTANENCE ........................................................................ 12
6.1 Operation and maintenance...................................................................................... 12
6.2 Storage ..................................................................................................................... 12
APPENDIX A: MODBUS COMMUNICATION................................................................... 13
A1: MODBUS register ..................................................................................................... 13
A1.1 MODBUS address ............................................................................................... 14
APPENDIX B: I2-∆T CURVES .......................................................................................... 15
B1: Example: how to utilize the curve ............................................................................. 15
B2: Nominal CT current: 1 A ........................................................................................... 16
B3: Nominal CT current: 1.5 A ........................................................................................ 17
B4: Nominal CT current: 2 A ........................................................................................... 18
B5: Nominal CT current: 4 A ........................................................................................... 19
B6: Nominal CT current: 5 A ........................................................................................... 20
1. SAFETY
1.1 Safety instructions
Make sure that any personnel installing and operating the thermometers:
- 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.
Safety instructions in this manual are shown in three different forms to emphasize
important information.
WARNING
This information indicates particular danger to life and health. Disregarding such a warning can lead to
serious or fatal injury.
CAUTION
This information indicates particular danger to equipment and/or other property of the user. Serious or fatal
injury cannot be excluded.
NOTE
This note gives important and specific information concerning the equipment.
1.2 Specified applications
The thermometer is used for oil-insulated transformers to measure the temperature of
transformer oil (OTI) or the windings temperature (WTI) using the thermal image principle.
It is important to observe the limit values indicated on the nameplate and in the manual
before commissioning the device.
1.3 Safety notes on the equipment operation
Electrical installation is subject to the relevant national safety rules.
It is mandatory to connect the grounding cable because of safety reason.
CAUTION
Installation, electrical connection and fitting the device have to 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.
WARNING
All relevant fire regulation must be strictly observed.
1
2. DRAWING
2.1 OTI/WTI/eOTI/eWTI
The dimensions of the following drawings are valid for the devices (with connection flange)
-
OTI: oil temperature indicator
WTI: winding temperature indicator
eOTI: oil temperature indicator with digital and analogue output
eWTI: winding temperature indicator with digital and analogue output
2
Fig. 1
3
2.2 Bulbs
Fig. 2
Fig. 3
4
3. OPERATING PRINCIPLE
3.1 Oil temperature indicator (OTI) – Oil temperature indicator with digital and
analog output (eOTI)
These devices are designed to measure the temperature of the insulating oil inside of
power transformer tanks. It’s possible to fit up to 5 change-over micro switches suitable to
control cooling equipment’s and protection circuits of transformer (alarm and trip).
The bulb of thermometer detects the transformer oil temperature variations generating a
contraction or expansion of the capillary connected to the pointer shaft. The adjustable
switching system connected to the pointer shaft provide the desired alarm/trip signals.
The electronic version of this kind of device, reading the signal from a PT100, give like
available:
- Analogue output 4-20 mA
- Modbus RTU communication (optional)
3.2 Winding Temperature Indicator (WTI) – Winding Temperature Indicator with
digital and analog output (eWTI)
The winding is a “high temperature” component in oil transformers, subjected to fast
temperature changes. Thus, an indirect system is used to measure the winding
temperature because it is dangerous to place a sensor close to the winding. This method
is called Thermal Image principle.
This instrument is designed to measure the temperature of winding by using a special bulb
surrounded by a heating resistance through which passes a current proportional to the
winding current under certain load and temperature conditions. It’s possible to adjust the
heating system by using a potentiometer placed on the instrument dial.
As indicated for OTI, this special bulb detects the temperature variations generating a
contraction or expansion of the capillary connected to the pointer shaft. The adjustable
switching system connected to the pointer shaft provide the desired alarm/trip signals.
It is possible to fit up to four change-over micro switches suitable to control cooling
equipment and protection circuits of transformer (alarm and trip).
The electronic version of this kind of device, reading the signal from a PT100, give like
available:
-
Analogue output 4-20 mA
Modbus RTU communication (optional)
Pt 100 (optional)
5
3.3 Outputs
STANDARD CONFIGURATION
STANDARD
(OTI)
STANDARD
(WTI)
OPTIONS
(eOTI-eWTI)
PT100
MICRO-SWITCHES
1 up to 4 x change over contact
MICRO-SWITCHES
1 up to 4 x change over contact
ANALOG OUTPUT
4-20
mA
(Maximum resistance: 450 Ohm)
COMMUNICATION PORT RS-485
Modbus communication – Appendix A
PT 100 port
Max 2 x OTI / WTI (1 Optional x eOTI / eWTI)
Table 1
3.4 Technical features
Standard connection flange
Material
Color
Dial
Ambient temperature
Degree of protection
Vibration damping
Ventilation valve
Cable gland
Wires
Micro switches, PT100 features
Insulation
4 holes Ø 7 mm, holes wheelbase Ø 175 mm
All the external part are resistant to transformer oils, salt fog and UV
rays **
White RAL 9002**
Tempered glass / Polycarbonate
-40°C to 80 °C
IP65 in accordance with EN60529
Optional anti-vibration supports available
N°2 to prevent the formation of condensation
Up to 3 x M25x1.5
Max 2.5mm2 – advised 4x1mm2 o 6x1mm2 shielded twisted pair cable
2000 V 50 Hz between terminals and earth for a 60 s time
1000 V 50 Hz between terminal in open position
Outputs (OTI/WTI)
Max 2 Pt100
Electronic board features (eOTI – eWTI)
Supply voltage (electronic
24 V dc ±10% polarized
devices)
Power consumption
0,5 W
Analog input (electronic devices)
1 x Pt100
1 x 4..20 mA insulated (dielectric strength between electronic card and
analogical output:2kV)
Analog output (electronic devices) Accuracy : 1.5 % of full scale
Maximum resistance: 450 Ω
1 x Pt100 (optional)
Distance for analogical output
Max 30 m / 98 ft (for different demands contact COMEM)
Serial RS485 Modbus RTU (for more information contact COMEM
Digital output
assistance dept.)
Distance for digital output
Max 30 m / 98ft (for different demands contact COMEM)
Available temperature range*
WTI / eWTI range
0 / +150°C, 0 / +160°C, 0 / +180°C
OTI / eOTI range
-20 / +130°C, -20 / +140°C, 0 / +120°C, 0 / +150°C, 0 / +160°C
* For specific range please contact Comem
** For critical environmental conditions please contact Comem
6
Table 2
Voltage
125 VAC
250 VAC
30 VDC
50 VDC
75 VDC
125 VDC
250 VDC
Micro switches making and breaking capacity
Standard Micro switches
High-performances micro switches
Resistive Load
Inductive Load
Resistive Load
Inductive Load
5A
5A
10 A
10 A
5A
5A
10 A
10 A
5A
5A
10 A
10 A
1A
1A
3A
2.5 A
0.75 A
0.25 A
1A
0.5 A
0.5 A
0.1 A
0.5 A
0.1 A
0.25 A
0.1 A
0.25 A
0.1 A
Table 3
3.5 Tests
Description
Measuring tolerance test and commutation tolerance test
Measuring tolerance test and commutation tolerance test
Leakage test
IP degree
Vibration test
REFERENCE STANDARD
EN50216-11
JB6302 – JB8450
EN50216-11
EN 60259
EN 60721-3-4 class 4M4
CEI EN 60068-3-3 (class 0,
level II)
Seismic test
Climatic test
Dry heat test (60°C 50%RH)
Dry heat test (40°C 93% RH)
Damp heat, steady state
Cold test
Damp heat, steady state
Damp heat cyclic
EMC
Fast transient/burst immunity test
Immunity to Conducted disturbances
Electrostatic discharge
Surge immunity test
Magnetic field immunity test
Immunity test
EN 60068-2-2 cl.6
EN 60068-2-2 cl.6
EN60668-2-78 cl7 and 9
EN 60068-2-1 cl.6
EN60668-2-78 cl7 and 9
IEC 60068-2-30
IEC 61 000-4-4
IEC 61 000-4-6
IEC 61 000-4-2
IEC 61 000-4-5
IEC 61 000-4-3
IEC 61 000-6-2
IEC 61 000-6-4
(EN 55022)
EN61000-4-8
IEC 61 000-3-2
IEC 61 000-3-3
EN 61000-4-11
Emission standard
Power-frequency magnetic field
Harmonic current emission
Voltage fluctuations and flicker
Micro-interruption and voltage variations
Table 4
7
4. INSTALLATION
CAUTION
The operating and the installation requirements described in this manual must be strictly following. If not,
the device can be damaged or a malfunction can occur.
4.1 Flange connection
The standard solution is with a flange connection. Arrange the transformer with a
dedicated place following the scheme in the figure 4. The connection can be done in two
alternative way:
- threaded pin
- screws
Fig. 4
4.1 Elastic Suspension (optional)
In case of high vibration withstand demand, the elastic suspension connection is available.
The actions that have to be followed are:
1. Unscrew the upper rigid locking M14 screw
located on the top of the thermometer (Fig. 5)
Fig. 5
8
2. Assembly the elastic suspension on the top of the
thermometer with a M14 screw that let install the instrument
in the plant (Fig.6-7)
Fig. 6
Fig. 7
5. ELECTRICAL CONNECTION
CAUTION
Qualified and skilled personnel trained in the applicable health and safety regulations of the relevant country
should only perform electrical connections.
WARNING
Dangerous electrical voltages!
It is imperative to deactivate the power supply during wiring of the device.
CAUTION
During the terminal box assembly, use caution not to damage the OR gasket (Fig.15/C). If this occurs, it
must be substituted.
If you do not use all the cable glands, pay attention to close the free cable gland with a plug with gasket.
5.1 Wiring diagrams
5.1.1 OTI – eOTI (2 , 4 contacts)
5.1.2 WTI – eWTI (2 , 4 contacts)
5.1.3 Pt100
9
5.2 Micro switches and PT100 (optional)
1. Removing of the terminal box cover: by unscrewing the four stainless steel captive
screws.
2. Cables layout: the numerations 1, 2, 3, 4, 5 indicate the micro switches progress:
red, blue, green, yellow, white pointer.
3. On the terminal board is written the cables layout for the different micro switches
utilizing the abbreviations:
·
·
·
C = common
NO = normally open
NC = normally closed
4. Connect the micro switches terminals and the earth terminal.
5. If the thermometer is equipped with the PT 100 probe, follow the label about how to
connect it
6. Re-position the terminal box cover.
5.2.1 Setting
To set the micro switches, follow the instructions:
1. Remove the locking ring (unscrew the eight M4 captive screws).
2. Remove the glass or polycarbonate lens.
3. Stop the micro switches setting dial (small black dial) with two fingers and slide the
fractioned micro switches setting pointers until they are located at the desired
temperature. Note that to reduce errors you have to slide the pointers towards
higher temperature value.
4. Replace the glass or polycarbonate lens taking care that the max. temperature
indicating pointer is located on the right side of the temperature indicating pointer
and that the lens itself correctly positioned over the sealing O-ring.
5. Lock the lens with the locking ring.
CAUTION
During the glass/polycarbonate lens removal, use caution not to damage the OR gasket. If this occurs, it
must be replaced.
If you do not use all the cable glands, pay attention to close the free cable gland with a plug with gasket.
10
5.3 ΔT calibration for thermal Image (WTI / eWTI)
Within the instrument’s terminal board there are, as well as earth and micro switches
connection terminals, the terminals T-T and the terminals A-A.
To calibrate the instruments, follow the steps:
1. Remove the jumper A-A.
2. Insert the ammeter probes in terminals A-A.
3. Connect the terminals T-T to the current transformer.
Be sure to use the right Current Transformer (CT) by checking that the CT nominal
current of CT is the one printed on the dial.
4. Regulate the current based on the curve I - ∆T (see Appendix A) rotating the
potentiometer until the read current on the ammeter corresponds to the value in the
curve.
5. Remove the ammeter probes.
6. Replace jumper A-A.
7. Wait few minutes to allow a stabilization of Tw.
8. Check the exactitude of Tw.
CAUTION
Some holes in the capillary bulb allow the oil flow and so the heat exchange providing a fast and accurate
measurement. The bulb must be inserted in a proper thermowell filled with transformer oil.The oil will rise
from the thermowell to the bulb holes covering the resistance.
5.4 eOTI/eWTI adding terminals
Terminal
numbers
SUPPLY VOLTAGE 24 V DC
ANALOG OUTPUT (4-20 mA)
COMMUNICATION PORT RS-485
(MODBUS communication)
Optional Pt100
1(-) – 2(+)
6(+) – 7(-)
3(A+) – 4(B-)
Table 5
ABb
11
6. OPERATION AND MAINTANENCE
6.1 Operation and maintenance
No particular maintenance is required. Only periodical inspections (typical interval 6
months) to verify precision, functions and electrical connections.
In case of working test effected with thermostatic bath, please note that WTI bulb MUST
NOT be immersed in water. The heating resistance surrounds the WTI bulb and water may
cause serious damages to the heating system. The calibration test must be done with oil
or hot air only.
When the instrument is equipped with polycarbonate lens, cleaning must be done with
care in order to avoid scraps on the surface. Use water and soap only.
NOTE
Comem advices to disconnect the eOTI/eWTI during the electrical transformer routine test
6.2 Storage
The devices can be handled without any tools. Handle the device with care.
The thermometers must be stored in the original packing and in a dry place with
temperature in the range -10÷40°C (14÷104 °F).
Upon receiving the device, please check:
· The outer surface of the packaging to ensure that it is intact
· That there are no breakages
If damages are found, please contact COMEM and provide the information from the
shipping list and the serial number.
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APPENDIX A: MODBUS COMMUNICATION
A1: MODBUS register
Register address
Operation
Notes
Operation for monitoring
0x2000
0x2001
0x2002
0x2003
0x2004
0x2005
0x2006
0x2007
0x200A
R
R
R
R
R
R
R
R
R
Pt100 value
Electronic board switched on time (minutes)
Electronic board switched on time (days)
Max Pt100 value of the current day
Min Pt100 value of the current day
Daily blackout number
Max scale value
Min scale value
Software version
Data logging
0x2100
0x2101
0x2102
0x2103
0x2104
0x2105
R
R
R
R
R
R
Max PT100 value of the day -1
Min PT100 value of the day -1
Max PT100 value of the day -2
Min PT100 value of the day -2
Max PT100 value of the day -3
Min PT100 value of the day -3
0x2134
0x2135
0x2136
0x2137
0x2138
0x2139
R
R
R
R
R
R
Max PT100 value of the day -27
Min PT100 value of the day -27
Max PT100 value of the day -28
Min PT100 value of the day -28
Max PT100 value of the week -5
Min PT100 value of the week -5
0x215C
0x215D
0x215E
0x215F
R
R
R
R
Max PT100 value of the week -23
Min PT100 value of the week -23
Max PT100 value of the week -24
Min PT100 value of the week -24
…….
…….
Event Log
0x2300
0x2301
R
R
0x2303
R
0x2304
…
0x248D
0x248F
0x2490
R
Available event (0 … 100)
Time Stamp 1
Event type 1:
1= alarm;
2 = trip;
3 = threshold trip;
4 = change date
Event 1 value
R
R
R
Time Stamp 100 (the oldest)
Event Type
Event Value
13
Table 6
A1.1 MODBUS address
When are installed two or more units, it is necessary to differentiate the MODBUS address
changing the dip-switches position
The available addresses are
· eOTI 80(default) to 95
· eWTI 96(default) to 111
Fig. 9
4
3
2
1
ADDRESS
eOTI
ADDRESS
eWTI
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
ON
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
Table 7
14
APPENDIX B: I2-∆T CURVES
B1: Example: how to utilize the curve
Starting data:
-
DT = 31 °C
-
CT nominal current = 2A
Enter in the graph with the known DT, it is possible to define the I2 (Fig. C)
Fig.C
I2 = 1.2 A
Rotate the potentiometer knob until the ammeter reading is 1.2 A
15
1A
B2: Nominal CT current: 1 A
Gradient (°C)
Stainless steel well
6
15
35
53
Gradient (°C)
Brass well
5
14
33
50
Heating current I 2 (A)
0.3
0.5
0.8
1.0
Notes:
-
Maximum WTI absorption power: 15 VA
-
Oil temperature set: 50 °C
16
1.5 A
B3: Nominal CT current: 1.5 A
Gradient (°C)
Stainless steel well
7
16
37
55
76
96
Gradient (°C)
Brass well
8
17
36
53
73
92
Heating current I2 (A)
0.3
0.5
0.8
1.0
1.2
1.4
Notes:
-
Maximum WTI absorption power: 25 VA
-
Oil temperature set: 50°C
17
2A
B4: Nominal CT current: 2 A
Gradient (°C)
Stainless steel well
3
6
16
23
31
44
59
69
Gradient (°C)
Brass well
3
6
15
21
28
41
57
66
Heating current I2 (A)
0.4
0.5
0.8
1.0
1.2
1.5
1.8
2.0
Notes:
-
Maximum WTI absorption power: 20 VA
-
Oil temperature set: 50°C
18
4A
B5: Nominal CT current: 4 A
Gradient (°C)
Stainless steel well
3
7
13
20
28
38
49
63
Gradient (°C)
Brass well
3
7
12
19
27
37
47
60
Heating current I2 (A)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Notes:
-
Maximum WTI absorption power: 20 VA
-
Oil temperature set: 50°C
19
5A
B6: Nominal CT current: 5 A
Gradient (°C)
Stainless steel well
1
3
6
9
14
20
26
34
42
51
Gradient (°C)
Brass well
1
2
5
8
12
17
23
30
38
47
Heating current I2
(A)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Notes:
-
Maximum WTI absorption power: 20 VA
-
Oil temperature set: 50°C
20
Strada Regionale 11, Signolo 22
36054 Montebello Vic.No (VI) - Italy
Tel. +39 0444 449311 - Fax -39 0444 449352 – 440359
http://www.comem.com
e-mail:comem@comem.com
21