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
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www.qualitrolcorp.com Page 2 of 34
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Information in this document is subject to change without notice. This document is provided to purchasers of
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©2021 QUALITROL® Company LLC, an ISO 9001 system certified company. All rights reserved. Information subject to change without notice.
All trademarks are properties of their respective companies, as noted herein. 40-08847-00-Rev001.

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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

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3.4 SCADA
4 - 20 mA output signal
Maximum 500 Ohms load
0 5 V output signal
Minimum 10k Ohm load
24 Volt Power Consumption
Maximum current < 0.25 Amp.
Dielectric Isolation: 4-20mA, 0-5V, PT100, Modbus
port
500 Vac to Ground for 60 seconds
Optional Power Supply: Voltage / frequency; rated
100 240 Vac 50/60 Hz, or 125 250 Vdc
Optional Power Supply: Voltage operating range
Per EN 60255-1; 80 to 110% of rated
Optional Power Supply: Dielectric Isolation-
MAINS port
2000 Vac to Ground for 60 seconds
Optional Power Supply: fusing
Internal 5 x 20 mm; T2A; 250V
Optional Power Supply; environmental
IP20
EMC immunity
Per EN 61000-6-5; Substation category, interface 4
Per IEEE C37.90.1,2,3
EMC emissions
Per EN55011; Class A
Terminal wiring: SCADA
0.5 1.5mm sq (16-20 AWG)
4. Safety
4.1 General Warnings
Operation outside of the intended use shall not be the responsibility of Qualitrol.
Refer to the installation manual for mounting details, and adjustment of the switches.
DO NOT APPLY HEAT TO THE THERMOMETER SENSOR BULB AT TEMPERATURES WHICH EXCEED THE
MAXIMUM RANGE OF THE DIAL.

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4.2 Capillary Routing
The capillary tube used on the AKM345 GEN3 is made from a soft copper to allow easy routing of the capillary.
If the capillary is kinked or crushed, the unit will be damaged.
To prevent kinking the capillary we recommend a minimum bend radius of 38mm [1].
4.3 Switch Wiring
Warning
Cabling or wires to the terminal strip must be rated to at least 80°C. For installations that are switching voltages
higher than 24V, the AKM345 GEN3 must be grounded to the transformer or control cabinet using 1.5mm2-
4mm2copper wire (16AWG-10AWG), with a ring terminal, and 5mm screw to the grounding spot provided.
Bonding must be made before and whenever the unit is energized.
4.4 Electrical Connection
Warning
•Make sure to ground the unit according to local regulations.
•Remote output signal connections must be made with shielded cabling.
•All user supplied wiring shall be rated at 80°C or higher.
•Do not disconnect protective grounding while unit is energized.
•Do not exceed 250V above ground for any switch or mains connection.
Grounding Terminal

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4.5 Power Connection
•Mains GROUND wiring to housing is shown as above in Grounding Terminal figure above, 
above ground potential.
•User shall supply a 5 or 10A double pole (or double fuse) time delay overcurrent protector at the MAINS
source.
4.6 4-20 mA Current Loop
•The 4-20mA current loop is scaled across the dial range.
•Attach the shield wire ONLY at the left/bottom printed circuit hold down screw using a ring or fork
terminal. Single point shield attach/grounding shall be made.
4.7 0-5 Volt Signal
•The 0-5 V dc output is scaled across the dial range.
5. Installation
•Before installation check for possible damage from transport or handling.
•Do not carry the instrument by the capillary. Do not twist the capillary when unwinding it or bend too
sharply. The minimum bend radius is 38mm [].
•Clamp it along its entire length at approximately 400 mm intervals. Excess capillary can be wound in a
spiral with min diameter 100 mm.
•For oil filled wells/pockets, be sure to leave 15% excess volume after probe is inserted for thermal
expansion.
•The non-vibration mountings included must be used to prevent mechanical wear caused by transformer
vibrations.
5.1 Mounting the AKM345
5.1.1 Mounting the Enclosure
The enclosure of the AKM345 GEN3 can be specified with a standard mount, universal mount, or seismic
mount.
•For the standard and seismic mounts, mount the unit using all 4 of the holes given on the mounting
brackets.
•For the universal mount, use at least 4 of the mounting holes given.
Do not modify the mounts in any way.

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5.1.1.1 Mounting Styles and Dimensions
5.1.1.1.1 Standard Mount
5.1.1.1.2 Universal Mount

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5.1.1.1.3 Seismic Mount
5.1.2 Installing the Probe
5.1.2.1 Pocket/Well Installation
The AKM345 GEN3 probe is designed to be installed in a pocket/well.
The pocket/well can be of dry-type or oil-filled.
NOTE: If using an oil filled well, be sure to leave 15% excess volume after probe is inserted for thermal
expansion. Failure to do so can result in damage to the probe or pocket/well.
Probe Installation Example

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5.1.2.2 Probe Types

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5.2 Front Cover
The AKM345 GEN3 features a new cover design that allows for the cover to be propped open or removed for
ease of access and installation.
The cover should not need to be removed unless the unit is being mounted in a cabinet or under a rain/sun
shield.
5.2.1 Opening and propping
Perform the following steps to open and prop open the front cover:
Step 1) Loosen the two bottom M5 captive screws to release the lid from the enclosure base. DO NOT remove
the screws from the lid.
Step 2) Open the lid to the 90° position.
AKM345 GEN3 with Cover Open
Step 3) Slide the cover latch pin into the cover hinge hole to secure it in the open position.
AKM345 GEN3 Hinge

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5.2.2 Cover Removal
To remove the front cover, perform the following instructions:
Step 1) Loosen two of the top M5 captive screws. DO NOT remove screws from hinge.
Step 2) While holding the lid, loosen two of the bottom M5 captive screws to release the lid from the
enclosure base. Again, DO NOT remove screws from the lid.
Step 3) Lid assembly can now be fully removed.
AKM345 GEN3 with Cover Removed

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5.3 Electrical Connection
5.3.1 Cable Glands
The unit can be specified to come equipped with cable glands as required, with all cable glands fitted, or with
blanking plugs instead of cable glands.
When specified with cable glands as required, the unit will be provided with M20 and M25 cable glands as
needed for the other features specified. i.e., # of switches, remote outputs, etc. and blanking plugs in unused
positions.
When specified with all cable glands fitted, the unit will be provided with 2 x M20 glands and 3 x M25 glands.
5.3.2 Switches
Wiring the switches on the AKM345 GEN3 is as follows:
•The first digit of each terminal number designates the switch number.
•The second digit of each terminal number designates the contact position.
o1 = common
o2 = normally closed
o4 = normally open
Switch Wiring Example
     


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5.3.3 Matching Resistance
To utilize the internal matching resistance of the AKM345 GEN3, you must connect your bushing CT directly to
the unit.
The CT input for the AKM345 GEN3 is designated on the terminal blocks as follows:
•5-5 = primary matching resistance (applicable to TD50, TD76, and TD50(5A))
•56-57 = secondary matching resistance (applicable to TD50(X2) and TD76(X2))
•NOTE: terminal block arrangement may differ depending on other options selected, but terminal
designation will remain the same
Matching Resistance Wiring Example
5.3.4 Power
In some configurations, the AKM345 GEN3 will require a power input for the remote indication or Modbus
communication.
-respectively.
The input power requirement is 24VDC.