Tesco Knopp KATC-C1 User manual

OPERATING INSTRUCTIONS
for the
TYPE KATC-C1
AUTOMATIC TRANSFORMER COMPARATOR
Serial Number: _______
Leaflet Number 2-048
Revision A
April 2014
Knopp Incorporated
1307 –66th Street
Emeryville, California 94608
[phone]
[phone]
[phone] (FAX)

Table of Contents 04/14
i
Table of Contents
General Information ..................................................................................1
Specifications............................................................................................2
Installation ................................................................................................4
Type KCTS Current Transformer Testing System ............................................... 4
Operation ...................................................................................................6
Description of Controls ........................................................................................ 6
ON/OFF Switch .......................................................................................... 6
REFERENCE TRANSFORMER Switch ........................................................ 6
TRANSFORMER-UNDER-TEST Switch....................................................... 6
RATIO ERROR Switch ............................................................................... 6
PHASE ERROR Switch............................................................................... 6
50/60 Hz LEDs............................................................................................ 6
MEASURE Push-button.............................................................................. 6
HOLD/RUNDOWN Push-button................................................................... 7
PRINT Push-button .................................................................................... 7
Operating Procedures .......................................................................................... 7
Connecting the Transformer-Under-Test .................................................. 7
Performing a Test...................................................................................... 7
One-to-One Test ................................................................................................... 9
Display Messages ................................................................................................ 9
Freq. Counter –no Start ............................................................................ 9
Freq. Counter –no Finish ........................................................................ 10
REF. COUNTER = 0 .................................................................................. 10
ERROR COUNT>REF. COUNT .................................................................. 10
S + E*COS() > 25.00................................................................................. 10
WRONG POLARITY .................................................................................. 10
PHASE ANGLE > 45° ................................................................................ 10
(S+Ecos)2+(Esin)2 >625 .......................................................................... 10
A/D not low (start) ................................................................................... 10
A/D not high ............................................................................................. 10
A/D not low (end) ..................................................................................... 10
REF CURRENT TOO HIGH ....................................................................... 10
ERROR CURRENT TOO HIGH .................................................................. 11
AUTORANGING........................................................................................ 11
RUNUP..................................................................................................... 11
MEASURE ................................................................................................ 11
HOLD/RUNDOWN ..................................................................................... 11

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ii
INVALID SWITCH SETTING ..................................................................... 11
SET CURRENT TO 0.00 ........................................................................... 11
XMTR not empty...................................................................................... 11
*** (Over-range Indicators) ..................................................................... 11
Troubleshooting and Repair.................................................................... 12
Doesn't Work The First Time ............................................................................. 12
Identical Or Near Zero Results.......................................................................... 12
Inaccurate Test Current Display ....................................................................... 13
Failed or Suspect Printed Circuit Card.............................................................. 13
Printed Circuit Card Listing ............................................................................... 13
Other Features ........................................................................................14
Serial (RS-232C) Communications Port ............................................................. 14
Serial Port Configuration ........................................................................ 14
Serial Port Baud Rate.............................................................................. 15
Remote Commands............................................................................................ 15
RS-232 Data Record Formats ............................................................................ 16
RATIO ERROR AND MINUTES ................................................................. 17
RATIO ERROR AND MILLIRADIANS ........................................................ 19
RATIO CORRECTION FACTOR AND MINUTES ........................................ 21
RATIO CORRECTION FACTOR AND MILLIRADIANS ............................... 23
REDUCED (TWO-LINE) PRINTOUT........................................................... 25
TEST CURRENT OUTPUT ........................................................................ 26
Warranty ..................................................................................................27

KATC-C1 Instructions Page 1 04/14
General Information
The Knopp Automatic Transformer Comparator (KATC-C1) is used to measure the ratio and phase
angle errors of current transformers with respect to a "standard" or "precision" transformer. This
microprocessor-based instrument automatically selects the optimum measurement range, computes
the results, and digitallydisplays several values, including:
the transformer ratio and phase angle errors,
the ANSIaccuracy class for which the transformer qualifies,
the test current in the secondaryof the precision transformer, and
the test current in the secondaryof the Transformer-Under-Test.
The KATC-C1 has protective circuitry which helps prevent damage when the Transformer-Under-
Test (TUT) is improperly connected.
A serial (RS-232C) input/output port is included as a standard feature. This port can be used to
download KATC-C1 test data to a computer for data storage and/or analysis. The port can also be
used to control various functions of the KATC-C1 from a computer.
The KATC-C1 is designed to test transformers with secondaries of one or five amperes. It automati-
cally senses, and adjusts to, operation at 50 or 60 Hz.
The KATC-C1 has been designed to make testing transformers as easy and fast as possible without
sacrificing accuracy or reliability. We trust that you will find it to be a useful instrument in performing
this task.
Chapter
1

KATC-C1 Instructions Page 2 04/14
Specifications
Input Power: 120 VAC, 50/60 Hz, lessthan 0.2 A
Test Frequency: 50 or 60 Hz
Test Current Range: 5% to 500% of selected range (1 or 5 amperes)
Ratio Error Range: 100% to +1000% (0 to 10 Ratio Correction Factor)
Phase Error Range: 1000 to +1000 minutes
Accuracy Class Range: 0 to 100
Accuracy: ±(0.75% of reading + 1 Least Significant Digit) or
(±0.01% ratio error and ±0.3 minutes phase angle er-
ror) whichever is greater
Interlock Relay: Capable of carrying 120/240 Volts at a maximum of
10 Amperes
Burden on Reference Transformer: Less than 0.2 VA (typical)
Burden on TUT Less than 0.2 VA (typical)
Resolution:
RCF
Phase
Angle
(Minutes)
Accuracy
Class
0.0 Accuracy Class < 0.2
0.00001
0.01
0.01
0.2 Accuracy Class < 0.7
0.00001
0.1
0.01
0.7 Accuracy Class < 1.4
0.0001
0.1
0.01
1.4 Accuracy Class < 10
0.0001
1
0.01
10 Accuracy Class
0.0001
1
0.1
Chapter
2

KATC-C1 Instructions Page 3 04/14
RS-232 Serial Communications Port: 1200 or 9600 baud (user selectable)
8 Data Bits
No Parity
2 Stop Bits
Bi-directional

KATC-C1 Instructions Page 4 04/14
Installation
The KATC-C1 Comparator is designed for use as a stand-alone unit, it can be purchased as part of a
complete test system, or it can be retrofitted into existing equipment. This chapter describes installa-
tion of the KATC-C1 intovarious pieces of test equipment and its use in a stand-alone environment.
Type KCTS Current Transformer Testing System
Typically, the KCTS is shipped with the KATC-C1 already installed. If you are upgrading from an
older-style Knopp comparator, proceed as follows:
1. Ensure that all power is removed from the KCTS!
2. Remove the four front-panel screws which secure the existing comparator to the KCTS.
3. Slide the comparator up and out of the KCTS, laying it upside down on the top of the KCTS
to gain access to the rear panel connections. Remove the rear panel connections from the old
comparator. Make sure that all leads are labeled so that it will be easy to place them on
the new comparator.
4. Set the old comparator aside and place the KATC-C1 on top of the KCTS so that the leads can
be attached. Connect the two interlock leads to the black five-way binding posts on the rear of
the KATC-C1 (polarity is not important). Next, connect the automatic run-down leads to the
solid-state relay mounted on the rear of the KATC-C1. Connect the power cord to the rear of
the KATC-C1.
5. Some rewiring will be necessary before connecting leads to the KATC-C1 terminal strip.
Refer to Schematic Diagrams Number 10280 (originally supplied with the KCTS) and 12278
(enclosed) for guidance. Proceed as follows:
a) Connect the lead marked “U” to the U terminal on the KATC-C1.
b) Remove anyconnections (if present) between Ground and the chassis of the KATC.
c) The lead previously marked “E” must be separated into two leads “E” and “E-bar” (E with
a bar over it). Referring to Schematic Diagram 10280, as originally built the E lead is con-
nected to terminal S1 on the One-to-One Test Switch and to the terminal labeled “5” for
connection of the secondary of the transformer-under-test. Now refer to Schematic Num-
ber 12278 and note that terminal S1 should be connected to the E terminal on the
Chapter
3

KATC-C1 Instructions Page 5 04/14
KATC-C1 and the “5” terminal should be connected to E-bar on the KATC-C1. Ensure
that the jumper from E-bar to the red binding post (DM) remains in place. It is important
that all connections are clean and tight and that wire of sufficient gauge (#6) is used.
d) Connect the lead marked “S” to the S terminal on the KATC-C1. Double check that all
connections have been made correctly and that they are all tight.
The drawing below shows the transformer connections to be made to the terminal board on the rear
panel of the KATC-C1 if the KATC-C1 is not used as a part of a test system. This connection allows
the KATC-C1 to be used with a standard transformer and burden in a “bench-top” situation. The "AC
Supply" shown on the drawing should be controlled by a variac —so that current can be applied
gradually.
PRIPRI
SEC SEC
S E E U
Burden
KATC-C1
Terminal
Board
Demag
Terminal
(Red)
±
±
±
±
Standard
Transformer Transformer Under Test
AC Supply

KATC-C1 Instructions Page 6 04/14
Operation
Description of Controls
ON/OFF Switch
Controls 120 VAC power to the KATC-C1.
REFERENCE TRANSFORMER Switch
Used to configure the KATC-C1 for use with reference (precision) transformers with 1 or 5 ampere
secondaries. Do not change this switch with current applied to the KATC-C1.
TRANSFORMER-UNDER-TEST Switch
Used to configure the KATC-C1 for testing transformers with 1 or 5 ampere secondaries. Do not
change thisswitch with current applied to the KATC-C1.
RATIO ERROR Switch
Allows the ratio error of the transformer-under-test to be displayed in Percent Error (%E) or Ratio
Correction Factor (RCF). [%E = 100 * (RCF-1)]
PHASE ERROR Switch
Allows the phase angle error of the transformer-under-test to be displayed in Minutes (MIN) or Milli-
radians (MR). [1 Minute = 0.29089 Milliradians]
50/60 Hz LEDs
Indicate whether the KATC-C1 has detected the applied test current to be 50 or 60 Hz. If no test
current is applied, the LEDs default to 60 Hz.
MEASURE Push-button
Toggles the KATC-C1 between MEASURE and RUNUP modes.
MEASURE mode should be selected when the desired test current has been reached. Selecting
MEASURE mode causes the KATC-C1 to begin taking measurements using the optimum meas-
urement range. Measurements can be taken at any current greater than approximately 4% of the
selected transformer-under-test secondary current. Selecting MEASURE mode erases any data
previously saved by pressing the HOLD/RUNDOWN push-button.
Chapter
4

KATC-C1 Instructions Page 7 04/14
RUNUP mode causes the KATC-C1 to not take any measurements, instead the KATC-C1 selects
its highest internal error range. This mode is used while the test current is being adjusted to mini-
mize chances of damage to the comparator.
This push-button is also used to reset the KATC-C1 after an error that caused an "alarm" condition is
corrected.
HOLD/RUNDOWN Push-button
"Freezes" the displayed data so that the test current can be reduced to zero —with the test data still
available. A box ( ¦) is shown in the display to indicate that the displayed data is “held” and will not
change if the test current is changed. Each press of the HOLD/RUNDOWN push-button causes the
display to briefly show the transformer-under-test secondary current to which the held values apply.
After a couple of seconds the displayreturns to a real-time displayof applied test current.
On systems with an automatic current rundown feature (such as the Knopp KCTS) pushing
HOLD/RUNDOWN also initiates rundown of the test current.
PRINT Push-button
Causes the displayed test result data, along with some heading information, to be sent to the device at-
tached to the RS-232 Serial Communications Port.Sample outputs are shown later in this manual.
Operating Procedures
Connecting the Transformer-Under-Test
If you are using the KATC-C1 without one of the Knopp Transformer Testing Systems, connect the
transformers according to the instructions for Portable Use as shown in the previous chapter. When
using the KATC-C1 with a Knopp Transformer Test System, refer to the instruction manual for your
system for transformer connection instructions.
Performing a Test
1. When power is first applied to the KATC-C1, the display will momentarily show RESET. After
this message disappears, test current is displayed and RUNUP mode is selected. Since the
KATC-C1 can be used with reference transformers and transformers-under-test with either 1 or 5
ampere secondaries, there are three different displays of test current provided to aid the operator.
The Reference Transformer secondary current is always shown as a percentage of the selected
secondary value (1 or 5 amperes). The Transformer-Under-Test secondary current is shown as
both a percentage and actual value.
2. Adjust the test current slowly to the desired value.
3. Pressing the MEASURE push-button toggles the KATC-C1 between RUNUP and MEASURE
modes.
RUNUP mode selects a high error current range on the KATC-C1 error measurement circuit.
This provides an extra measure of safety to the equipment and allows the current to be in-
creased more quicklythan when the KATC-C1 is in the measure mode.