Probewell ATK-3 User manual

ACCURACY TEST KIT
USER GUIDE FOR ATK-3 & ATK-4
Version 3.0 – February 2023
BEFORE PUTTING THIS PRODUCT INTO SERVICE,
IT IS ESSENTIAL THAT THIS INSTRUCTION BOOK BE
READ THOROUGHLY.

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
2
© Copyright 2020 by Probewell Lab Inc. Printed in Canada.
All rights reserved, including those to reproduce this manual or parts thereof, in any form without the
express wrien permission of Probewell Lab Inc.

3
Limited Warranty
Your Accuracy Test Kit (ATK-3 or ATK-4) comes with a two-year hardware warranty.
Probewell Lab Inc. (Probewell) warrants this product against defects in material and work-
manship for a period of two (2) years from the date of purchase from Probewell or an
authorized Probewell agent. This warranty applies only to the original purchaser of this
product and is not transferable.
This warranty does not cover any damage caused by negligence, non- authorized modi-
caons, or parts installed without prior wrien permission from Probewell.
This warranty does not apply if the product has been damaged by accident, abuse, mis-
use, or misapplicaon, nor as a result of service to the product by anyone other than
Probewell.
PROBEWELL IS NOT RESPONSIBLE FOR ANY LOST PROFITS, LOST SAVINGS OR
OTHER INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE,
OR INABILITY TO USE, OF THIS PRODUCT. THIS INCLUDES DAMAGE TO PROPERTY
AND DAMAGES FOR PERSONAL INJURY. THIS WARRANTY IS IN LIEU OF ALL OTH-
ER WARRANTIES INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE.
Disclaimer
Probewell Lab Inc. (Probewell) reserves the right to make changes to this document and
the products which it describes without noce. Probewell shall not be liable for technical
or editorial errors or omissions made herein; nor for incidental or consequenal damages
resulng from the furnishing, performance, or use of this material.
Features and specicaons are subject to change without noce.

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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Table of Contents
Limited Warranty ........................................................................................................... 3
Disclaimer ......................................................................................................................... 3
Table of Contents .......................................................................................................... 4
Chapter 1
Descripon ................................................................................................................................ 5
Equipment Required ..................................................................................................... 5
How it works ................................................................................................................... 6
Chapter 2
Connecon ................................................................................................................................ 7
Chapter 3
NT Series Tester .................................................................................................................... 11
Accuracy Tesng Procedure (NT Series) ........................................................... 11
User Calibraon (NT Series) ................................................................................... 13
Troubleshoong (NT Series) ................................................................................... 15
Chapter 4
Accuracy Tesng Procedure (WT Series) ................................................................... 17
Pairing the device ....................................................................................................... 17
Accuracy Test Sengs ....................................................................................18
Main Accuracy Test Screen ............................................................................19
While Performing the Accuracy Test ...........................................................20
Accuracy Test Completer ...............................................................................21
User Calibraon (WT Series) ................................................................................. 22
Troubleshoong (WT Series) ................................................................................. 24
Chapter 5
Accuracy Report (WT Series)
.......................................................................................... 27
Appendix A
Addional Connecon Diagrams .................................................................................. 30

CHAPTER 1: DESCRIPTION
5
Chapter 1
Description
The accuracy of MT-1/NT3, MT-1/NT4, MT-1/NT5, MT-1/NT9, MT-1/WT1 and
MT-1/WT3 can be checked against a NIST traceable standard using the following test
procedure. The accuracy is tested on 6 dierent current test points: 1.5, 3.0, 5.0, 15.0,
30.0 and 50.0A at both 1 (0°) and 0.5 lag (60°) power factors in Wh. Addionally the NT9
and WT3 does VARh at 30° and 90°. The accuracy test can be done using a stabilized and
isolated AC power source at either 120 or 240 volts.
Equipment Required
• A primary or secondary electronic wahour standard traceable to NIST, with an
output of 10µWh or 20µWh per pulse, from the BNC port.. The standard must have
at least one isolated current input port of a minimum capacity of 50 A with autoran-
ging capability. We recommend a standard with an accuracy of 0.02% or beer.
• The Probewell Accuracy Test Kit (single-phase or three-phase). The Kit includes the
following items:
• An Accuracy Test Interface (PW-8967), a BNC coaxial cable and a Probewell
extension cable RJ12 type connecon.
• An Accuracy Test Jack.
• Three-phase (ATK-3) for MT-1/NT3, MT-1/NT9 and MT-1/WT3
• Single-phase (ATK-4) for MT-1/NT4, MT-1/NT5 and MT-1/WT1
• MT-1/NT3 and MT-1/NT7 (discounnued models)
• A laboratory stabilized and isolated AC power source with fundamental waveform
selectable at 120V or 240V ±5%, 58~62 Hz, rated at least 150VA.
A laboratory stabilized, and isolated AC power source is preferred rather
than a small isolated line transformer or autotransformer. Such small
transformers could generate severe harmonics and voltage uctuaons
which could cause small addional measuring errors. Always fuse the
power leads going to the rear tabs 1 & 3 of the unit with a quick acon 1 A
fuse. The power leads and fuses are not provided with the Accuracy Test
Kit (ATK)..

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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How it works
The previously described setup is used to check the accuracy of the internal Wh standard
of the unit under test against a NIST traceable Wh standard. The unit is tested at six
(6) current test points: 1.5, 3.0, 5.0, 15.0, 30.0 and 50.0 A at both 1 and 0.5 lag power
factors.
The meter that is normally inserted in the front of the unit is replaced by a NIST traceable
standard. The standard is hooked up through a test jack in the front of the unit. A pair
of #4 AWG cables connect the test jack to the input current terminals of the standard.
Also, a pair of #18 AWG test leads are connected to the standard’s voltage terminals.
The current and voltage are both generated by the unit. The current produced by the
unit is the same current as the one circulang through the input current terminals of the
standard.
The internal wiring of the test jack connects the unit’s current elements in series to a
single element of the standard.
T he standard sends a set number of pulses to the Accuracy Test Interface through the
coaxial cable. These pulses correspond to very precise units of energy. These pulses can
be either 10µWh (high pulse rate) or 20µWh (medium pulse rate) depending on the model
of the standard used. The Probewell Connect 2.0 Accuracy Test Interface accepts either.
It processes these pulses from the standard and then sends them to the unit’s embedded
processor. The Accuracy Test Interface is made up of digital circuitry only. It acts as a
programmable digital divider which is not sensive to heat and will not dri in me.
During the test, the embedded controller of the unit registers the energy measured by
the standard (cumulated pulses converted to Wh) and the energy measured by the unit
being tested (internal Wh standard). These two measurements are independent of one
another. When they converge toward the same value, the unit’s internal Wh standard
is considered well calibrated and the % error is very close to zero. A summary is shown
when the test is completed.

CHAPTER 2: CONNECTIION
7
Chapter 2
Connection
Cauon: This procedure involves high voltage. Use extreme
cauon in working with and making connecons.
Always wear appropriate protecve equipment.
1. With insulated alligator clips, connect the power leads from the AC power source
to tabs 1 and 4 located at the back of the Probewell unit. Always leave the Form
Selector switch in the 2S posion (lemost).
 Three-phaseUnitPowerConnecon Single-phaseUnitPowerConnecon
Fig. 1:
MT-1/NT3*, MT-1/NT9 and MT-1/WT3
Fig. 2:
MT-1/NT4, MT-1/NT5 and MT-1/WT1
*MT-1/NT3 and MT-1/NT7 (discounnued models)

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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2. Install the test jack on front of the unit in test. Connect the current and voltage
wires between the test jack and the standard while respecng the polarity (see Fig.
3). Refer to the Standard’s manufacturer for details on how to connect the Aux.
Power ports.
Fig. 3 – Test jack (ATK-3 or ATK-4) to Standard Connecon
To remove the test jack, power o the unit and insert a large at screwdriver
in the notch located on the boom side of the rim to pry it out of the unit
in test.

CHAPTER 3: NT SERIES TESTER
9
3. Connect the coaxial cable from the Input (pulses) BNC connector on the Accuracy
Test Interface to the output pulses BNC connector of the Standard. Then, connect
the unit in test’s I/O port to the Accuracy Test Interface (port 1, le) with the
provided RJ12 extension cable. For NT series, connect the handheld remote to the
other port of the Accuracy Test Interface (port 2, right) using a RJ12 extension cable.
For WT series, port 2 of the Accuracy Test Interface is unused.
The Accuracy Test Interface is powered by the test socket itself. A red LED
indicates the presence of power.
NT Series WT Series
Input (pulses)
Power Led
To the
Test
Socket
To the
Handheld
Remote
Input (pulses)
Power Led
To the
Test
Socket
Fig. 4 - Accuracy Test Interface

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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CHAPTER 3: NT SERIES TESTER
11
Chapter 3
NT Series Tester
AccuracyTesngProcedure(NTSeries)
1. Turn on the AC power source. Hold the Reset Key of the handheld remote and turn
on the unit in test. Aer a few seconds, the Conguraon Menu appears on the
handheld. The Reset Key must be held unl the following screen appears:
2. Use the Mode Key (press mulple mes) to navigate to the Accuracy Test sub-menu
which will appear on the second line of the display screen. The following display
should appear.
3. Press the ENTER Key to access the Accuracy Test sub-menu. The following display
should appear.
By default, the pulses are set at 10µWh/pulse. Use the arrows to select the pulse
rate (10 or 20µWh) and power factor (PF) which can be either 1 (0o) or 0.5 (60 o) lag.
For MT-1/NT9 you also have the opon to verify the VARh at 30 o and 90 o lag.
The µWh/pulse values of the standard and handheld must match.

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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4. Press the Start Key to begin the test. The unit in test runs an inializaon sequence
which includes checking the wiring setup and auto-scaling.
If the cables are not properly connected, an error message appears on the
remote. For maximum safety, turn o both the AC power source and unit
in test. Check all the connecons (polarity) and go through steps 4 to 7
again.
Don’t forget to congure the standard in Wh (wahour) mode. Make
sure that the coaxial cable between the Standard’s output pulse and the
Accuracy Test Interface is properly connected.
5. Aer inializaon, the test begins automacally. The second line displays the energy
(Wh) recorded by the unit in test. The third line displays the energy (Wh) measured
by the standard. The fourth line shows the current test point being tested in amps
and the % error. The % error shall converge (less than 20 seconds) towards the
result.
6. At the end of each test point, the unit in test emits a single beep. The result is dis-
played for a period of 5 seconds aer each test point.
7. When all 6 test points are completed, the unit in test emits a triple beep. This in-
dicates the end of the test. At this step, the handheld displays results for the rst
3 current points.
8. Press the Mode Key to navigate through the results.

CHAPTER 3: NT SERIES TESTER
13
9. Press the Mode Key again and a summary report showing the accuracy of the unit
test appears on the display.
If the average error of the unit is within specicaon, it does not need to be
calibrated in shop. Otherwise, please follow the User Calibraon procedure to apply
a user dened calibraon factor.
The unit’s internal Wahour Standard does not contain potenometers or
any other type of mechanically adjusted device that could shi or become
unstable with me. This means that the accuracy should not change
much over the lifeme of the product. However, if a unit does need to be
recalibrated, follow the User Calibraon procedure on the next page.
10. To save the Accuracy Report, press the Reset Key once and the Saving Menu
appears. Press the PF Key to save the Accuracy Report in the non-volale memory
of the handheld.
UserCalibraon(NTSeries)
Once the test procedure is complete, the user may choose to apply a specic, single
percentage calibraon oset to the unit. This is useful when the unit calibraon must
match a NIST traceable standard. The maximum value for this oset is ± 0.05%, by steps
of 0.001%. The deviaon is set at 0.000% (nil) by default. The User Calibraon correcon
factor is stored in the non-volale memory of the unit socket.
Procedure
1. Write down the average error percentage result given by the accuracy test. Exit the
Accuracy Test Menu by pressing twice on the Reset Key, then press the Mode Key
to reach the User Calibraon menu entry and press the ENTER Key to access. The
following sub-menu appears:
To change the calibraon factor, use the arrows to decrease or increase the deviaon
percentage.

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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Calibraon Factor
When the average error given at the end of the accuracy test is posive, the unit measures
more energy than it should and must be slowed down by that amount. Therefore, the
absolute value of the error should be subtracted.
When the average error given at the end of the accuracy test is negave, the unit
measures less energy than it should and must be speed up by that amount. Therefore,
the absolute value of the error should be added.
Example1: If the average error is +0.028%, and the value in the sub-menu is
-0.005%, subtract 0.028% and the value shown on the display be-
comes -0.033% [ -0.005% - 0.028%].
Example2: If the average error is +0.028%, and the value in the
sub-menu is +0.035%, the new value would be +0.007%
[ +0.035% - 0.028 %].
Example3: If the average error is -0.026%, and the value in the
sub-menu is -0.035%, the new value would be -0.009%
[ -0.035% + 0.026%].
Example4: If the average error is -0.029%, and the value in the
sub-menu is +0.008%, the new value would be +0.037%
[ +0.008% + 0.029%].
2. Once the new value is wrien in, press the Reset Key. You are then asked to enter
the calibraon date (the default date is the current one). The following appears:
3. Once the date is set (using the eding keys), press the Reset Key twice and the
Saving Menu appears. Press the PF Key to save the new value in the non-volale
memory of the NT Series socket meter tester. The unit is now calibrated against
your traceable Standard.
At power on, the message Cal yyyy/mm/dd appears on the display.
Without parentheses, the date indicates when the unit was calibrated
by Probewell before shipment. When the message is shown between
parentheses, it means that the unit has been calibrated according to
your specicaons in your own shop.

CHAPTER 4: WT SERIES TESTER
15
Troubleshoong(NTSeries)
The following are some of the common issues that may occur when using the Accuracy Test
Kit and suitable soluon to resolve them. If issue persists, please contact Probewell Technical
Support by email at [email protected]om or visit www.support.probewell.com.
Wrong Setup
• This message appears when no pulse is detected from the Wh standard. Check the
wiring setup at g. 2. Be sure that the polarity is respected.
• Make sure that the standard is set up in Wh (wahour) mode.
• Make sure that the coaxial cable linking the Standard’s pulse output to the Accuracy
Test Interface input is properly connected.
• Make sure that the energy/pulse constant (in µWh/pulse) from the Standard matches
the input pulse selected on the handheld.
Line Voltage Out of Range
• Line voltage is o by more than 5% of the nominal voltage. Check the voltage of the
AC power source.
High Burden could aect calibraon
• Make sure that the screws of the voltage and current ports on the Standard are ght
enough. If necessary, use a ½’’ box wrench to ghten.
• An abnormally high burden may prevent the current from reaching 40 A. The
calibraon cannot be completed under such condions.
• With a medium, but sll acceptable burden load, the maximum test current will be
limited. The max value will lie between 40 A and 50 A. The calibraon can sll be
done, but only up to the highest load that can be reached (e.g. 45 A).
• Make sure that the front jaws of the unit in test are clear of corrosion and debris. If
the problem persists, try switching to another output port of the Standard for current.
Please keep these points in mind if your Calibraon report diers
from the one provided by Probewell
• There may be Small deviaons in the AC power source. Distoron on the AC
voltage waveform will result in a reducon of accuracy proporonal to the order and
magnitude of the harmonics. To minimize waveform errors, the AC voltage waveform
must be sinusoidal and as pure as possible.
• Avoid using line regulators that contain a self-resonant transformer. Those generate
strong harmonics of several kHz.
• Avoid using small (100 VA and less) transformers as the AC power source. Such small
transformers produce strong harmonics of several kHz and introduce measuring
errors on both the MT-1 unit and the standard that can reach ± 0.05%. Harmonics
are produced by the magnezing current drawn by the core (not sinusoidal) and the
relave high winding resistance.

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
16

CHAPTER 4: WT SERIES TESTER
17
Chapter 4
Accuracy Testing Procedure
(WT Series )
Pairing the device
1. Turn on the AC power source. Turn on the unit in test. Once started, the unit will
emit a three-tone sound sequence.
2. Launch the Probewell Connect 2.0 applicaon from your computer.
The following screen should appear:
Fig. 5 – Probewell Connect 2.0 inial display
3. Pair the computer to the unit’s wireless network.
For instrucons on how to connect to the unit’s network, please refer to the
Connecng to the MT-1/WT secon in the tester User’s Guide or the connecon
guidelines provided with the unit.

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
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AccuracyTestSengs
1. Upon connecon, Probewell Connect 2.0 automacally displays the Setup tab.
2. The Measurements secon (1) of the Accuracy Test screen displays the congurable
test parameters and the Standard secon (2) shows the reference Wh standard
idencaon parameters ( The congurable standard idencaon parameters are
self-explanatory and are only used for traceability, but the date eld is mandatory and
will be used as the standard’s calibraon date ).
Fig. 6 – Probewell Connect 2.0 Accuracy Test (Test Parameters)
ThecongurableAccuracyTestparametersare:
Measurement type
Wahour or VARHour. Must match the pulse output parameter of the reference
standard.
Lag factor
Unity (100% PF) or Half-Power (50% PF). Translates to a 0o or -60 o phase angle in
Wh and to a 90 o or 30 o phase angle in VARh.
Pulse constant
10 µWh/pulse or 20µWh/pulse. Must match the pulse output parameter of the
reference standard.
Voltage
Between 120 and 480 Volts. Must match the AC voltage source and be within 5%
of the specied value.
Frequency
Not congurable. Set at 60 Hz.
3. Congure the measurement parameters and ll in the Standard secon, then click
the green checkmark to conrm the sengs.
1
2

CHAPTER 4: WT SERIES TESTER
19
Main Accuracy Test Screen
1. Once the informaon on the Setup tab have been lled in and conrmed, the user is taken
to the main test screen.
Fig. 7 – Probewell Connect 2.0 Accuracy Test screen
1. Test ID and descripon
2. Status eld
3. Control (Start and Stop test)
4. Measurement parameters
5. Reference Standard ID
6. Edit Measurement and Standard eld
7. Tester model
8. Results
9. Six test points
10. Minimum, Maximum and Average
2. Press the Play buon to begin the test. The unit in test runs an inializaon
sequence which includes checking the wiring setup and auto-scaling.
• If the cables are not properly connected, the applicaon displays
an error message. For maximum safety, turn o both the AC power
source and unit in test. Check all the connecons (polarity) and
validate the value of the Measurement parameter secon.
• Don’t forget to congure the standard in Wh (wahour) mode. Make
sure that the coaxial cable between the Standard’s output pulse and
the Accuracy Test Interface is properly connected.
3. Aer proper inializaon, the test begins automacally.
1
2
4
8
9
10
5 6 7
3

ACCURACY TEST KIT USER GUIDE FOR ATK-3 & ATK-4
20
While performing the Accuracy Test
4. The status eld reads «Test in Progress»
5. The current test point being tested is idened by a spin wheel.
6. At the end of each test point, the unit in test emits a single beep. The % error of the
current test point is registered, and the test result table is duly updated.
Fig. 8 – Probewell Connect Accuracy Test (Test in progress)
7. The boom poron of the Accuracy Test display shows the test results.