Qualitrol OTIWTI AKM345 GEN3 User manual

QUALITROL AKM345 GEN3 OTIWTITM
OTIWTI™ AKM Type 34 Oil Temperature Indicator
OTIWTI™ AKM Type 35 Winding Temperature Indicator
Document ID: 40-08847-00-Rev001

QUALITROL AKM345 GEN3 OTIWTITM Instruction Manual
40-08847-00-Rev001
www.qualitrolcorp.com Page 2 of 34
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About Qualitrol®
QUALITROL® manufactures substation and transformer monitoring and protection devices used by electric utilities
and OEM manufacturing companies. It is the global leader in sales and installations of transformer asset protection
equipment, fault recorders, and fault locators. Established in 1945, QUALITROL® produces different types of
products on demand, customized to meet unique requirements.

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Table of Contents
1. List of Abbreviations/Acronyms......................................................................................................................... 6
2. Introduction....................................................................................................................................................... 7
2.1 QUALITROL AKM345 GEN3 OTIWTITM........................................................................................................ 7
2.2 Operation................................................................................................................................................... 8
2.3 Calibration Check....................................................................................................................................... 8
2.4 Winding Simulation.................................................................................................................................... 8
2.5 Switches..................................................................................................................................................... 8
2.6 Remote Output.......................................................................................................................................... 9
2.7 MODBUS .................................................................................................................................................... 9
3. Specifications..................................................................................................................................................... 9
3.1 Environmental.......................................................................................................................................... 10
3.2 Electrical................................................................................................................................................... 10
3.3 Mechanical............................................................................................................................................... 10
3.4 SCADA ...................................................................................................................................................... 11
4. Safety ............................................................................................................................................................... 11
4.1 General Warnings .................................................................................................................................... 11
4.2 Capillary Routing...................................................................................................................................... 12
4.3 Switch Wiring........................................................................................................................................... 12
4.4 Electrical Connection ............................................................................................................................... 12
4.5 Power Connection.................................................................................................................................... 13
4.6 4-20 mA Current Loop ............................................................................................................................. 13
4.7 0-5 Volt Signal.......................................................................................................................................... 13
5. Installation ....................................................................................................................................................... 13
5.1 Mounting the AKM345 ............................................................................................................................ 13
5.1.1 Mounting the Enclosure .................................................................................................................. 13
5.1.2 Installing the Probe.......................................................................................................................... 15
5.2 Front Cover .............................................................................................................................................. 17
5.2.1 Opening and propping ..................................................................................................................... 17
5.2.2 Cover Removal................................................................................................................................. 18
5.3 Electrical Connection ............................................................................................................................... 19
5.3.1 Cable Glands .................................................................................................................................... 19
5.3.2 Switches........................................................................................................................................... 19
5.3.3 Matching Resistance........................................................................................................................ 20

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5.3.4 Power............................................................................................................................................... 20
5.3.5 Remote Output ................................................................................................................................ 21
5.3.6 Modbus............................................................................................................................................ 22
6. Switch Setting .................................................................................................................................................. 23
6.1 Switch Setpoint Adjustment .................................................................................................................... 23
6.2 Adjustable Differential (option)............................................................................................................... 24
7. Winding Temperature Simulation ................................................................................................................... 25
7.1 Adjusting the Internal Matching Resistance TD50 & TD76................................................................... 26
7.2 Using the Internal 5 Amp CT Option TD50(5AMP)................................................................................ 27
7.2.1 Background ...................................................................................................................................... 27
7.2.2 Setting the Matching Resistance ..................................................................................................... 27
7.3 Dual Gradient (option) TD50(X2) & TD76(X2)....................................................................................... 29
7.3.1 Background ...................................................................................................................................... 29
7.3.2 Wiring Recommendations ............................................................................................................... 29
7.4 External Matching Units .......................................................................................................................... 30
8. MODBUS Communications (option) ................................................................................................................ 31
8.1 MODBUS Default Configurations............................................................................................................. 31
8.2 Event Reporting Over MODBUS............................................................................................................... 31
8.3 MODBUS Register Map............................................................................................................................ 31
8.3.1 MODBUS Registers........................................................................................................................... 31
8.3.2 Input Registers................................................................................................................................. 32
8.3.3 Discrete Inputs................................................................................................................................. 32
8.3.4 Holding Registers ............................................................................................................................. 33
8.3.5 MODBUS Notes................................................................................................................................ 34
9. Troubleshooting............................................................................................................................................... 34
9.1 Matching Resistance................................................................................................................................ 34
9.2 Remote Outputs....................................................................................................................................... 34

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1. List of Abbreviations/Acronyms
Abbreviation/Acronym
Expansion
AKM345
Qualitrol Product Family of Oil and Winding
Temperature Indicators
GEN3
Third Generation Product
OTI
Oil Temperature Indicator
WTI
Winding Temperature Indicator
MBO
Magnetic Blow-Out Contact
WHS
Winding Hottest Spot
OTIWTI
Qualitrol Trademarked Oil and Winding
Temperature Indicators

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2. Introduction
2.1 QUALITROL AKM345 GEN3 OTIWTITM
The Qualitrol AKM345 GEN3 OTIWTITM is the future of oil and winding temperature indication for transformers
of all classes. The GEN3 is a world class, robust, feature packed temperature indicator designed and
manufactured for long and trouble-free operation in all conditions.
The AKM345 GEN3 OTIWTITM is a remote mount, bellows style, temperature indicator used on transformers for
indicating Oil Temperature (OTI) or Winding Temperature (WTI). The AKM345 is used for activating cooling
equipment, alarming on temperature, and electronically transmitting temperature readings.

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2.2 Operation
The AKM345 operates using a bellows type technology. A temperature probe is installed in a pocket/well located
in the transformer wall or cover. The probe is connected to a sealed system capillary filled with oil that is then
connected to the bellows system in the enclosure of the unit. As the temperature of the oil in the probe
increases, the oil expands also expanding the bellows and as a result driving the dial of the unit along with
switches and remote outputs.
On WTI units, the load current from the bushing CT can be brought directly into the enclosure of the AKM345 to
be used for simulating winding temperature. Winding temperature is simulated from a heater located in the
bellows of the unit providing accurate and reliable gradient indication.
The switches can be used for cooling control and alarming. The remote outputs can be used to transfer data to
a local or remote monitoring system.
2.3 Calibration Check
Each AKM345 instrument is factory calibrated and no further calibration is required.
If the calibration of the AKM345 needs to be verified, please follow the below procedure:
•Place the probe in bath of boiling water (100°C) or a calibrated oil bath set to 100°C
onote, the minimum volume of water or oil should be 5 liters!
•Stir the contents of the oil/water bath to ensure even temperature distribution and check that the
temperature of the bath is 100°C (check with a calibrated thermometer)
•Read the temperature on the device thermometer after 15 minutes
If the difference between the temperature indicated by the AKM345 unit and the temperature of the
bath is greater than 5°C we recommend contacting Qualitrol for further assistance
2.4 Winding Simulation
The AKM345 GEN3 OTIWTITM has a method to simulate the temperature of a winding by indirect measurement
called thermal image. This is a frequently used simulation method that senses top oil temperature and biases
the thermometer reading proportional to transformer load to indicate winding temperature.
On WTI units, the load current from the bushing CT can be brought directly into the enclosure of the AKM345 to
be used for this method of simulating winding temperature. Winding temperature is simulated from a heater
located in the bellows of the unit providing accurate and reliable gradient indication.
On the AKM345 a matching resistance is used to adjust the current needed by the heating element to provide
the required winding hottest spot (WHS) temperature gradient delivering a parallel path to divert part of the
total current. There are 3 internal matching resistance models (TD50, TD76, and TD50/5) and 2 external matching
resistance models (AKM 44674 and AKM 44678).
2.5 Switches

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The AKM345 GEN3 OTIWTITM can be equipped with 2, 4, or 6 Form C contact switches. These switches can be
used for alarming and control of cooling equipment.
Each switch is independently adjustable across the dial range. Switching accuracy is ±3% of the dial range.
As an option, the switches can be specified for high DC current applications or with gold contacts for intrinsic
environments.
More information is available in section 6 of this manual.
2.6 Remote Output
The AKM345 GEN3 OTIWTITM can be equipped with various remote outputs for connecting to a SCADA or
monitoring system.
Powered outputs include a 4-20mA, 2 x 4-20mA, or 4-20mA & 0-5VDC, outputs. These outputs are scaled evenly
across the specified dial range.
An additional non-powered output is available as a Pt100 resistance signal. The Pt100 signal will correspond to
the temperature as per the Pt100 resistance curve.
More information is available in section 5.3.5 and wiring recommendations are available in section 8.
2.7 MODBUS
The AKM345 GEN3 OTIWTITM can be specified to include RS-485 Modbus communication.
Modbus communication can only be specified with a powered remote output.
Further information is available in section 8 of this manual.
3. Specifications

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3.1 Environmental
Storage Temperature
-50°C to 80°C
Ambient Operating Temperature
-40°C to 70°C; Optional for -60°C
Enclosure protection
IP66
General Requirements
Per IEC 60076-22-1, section 7.8
Overvoltage category, Pollution degree, Class
Category III, Pollution degree 2, Insulation Class 1
3.2 Electrical
Dielectric Isolation- SWITCHES
2000Vac to Ground for 60 seconds
Standard Switch Rating (<250V ac)
15A; resistive or <7ms inductive
Standard Switch Rating (125V dc)
0.75A resistive/ 0.4A <7ms inductive
Standard Switch Rating (250V dc)
0.3A resistive/ 0.2A <7ms inductive
MBO Switch Rating (125V ac/dc)
10A resistive/ 6A <7ms inductive
MBO Switch Rating (250V ac/dc)
3A resistive/ 1.5A <7ms inductive
Gold (dry circuit) Switch Rating (125V dc)
0.1A resistive
Switch terminal wire size; torque
1.5 to 4mm sq; 0.8 N-m (6-8 in-lbf)
3.3 Mechanical
Dial and switch accuracy
For T > 0 deg: +/- 2% of Full-Scale Range
Seismic; switch stability
Per IEC 60068-3-3; Level II
Vibration; switch stability
Per IEC 60721-3-4; Class 4M4
Shock; switch stability
Per IEC 60721-3-4; Vertical axis, Type 1