Guildline 6624CT-3000 User manual

Operation Manual
For The
6624CT-3000
High Current DC Transformer
www.guildline.com
NOTICE
The contents and information contained in this manual are proprietary to
Guildline Instruments Limited. They are to be used only as a guide to the
operation and maintenance of the equipment with which this manual was
issued and may not be duplicated or transmitted by any means, either in whole
or in part, without the written permission of Guildline Instruments Limited.
OM6624CT-3000-A-00
11 May, 2016

OM6624CT-3000-5-00
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TABLE OF CONTENTS
1. INTRODUCTION.......................................................................................................1-1
1.1. SCOPE................................................................................................................................................................1-1
1.2. GENERAL DESCRIPTION............................................................................................................................1-1
1.3. OVERVIEW ......................................................................................................................................................1-2
1.4. PRINCIPLE OF OPERATION.......................................................................................................................1-2
2. INSTALLATION ........................................................................................................2-1
2.1. PRELIMINARIES............................................................................................................................................2-1
2.1.1. Unpacking.......................................................................................................................................................2-1
2.1.2. Power Voltage Selection ................................................................................................................................2-1
2.1.3. Fuse Replacement...........................................................................................................................................2-2
2.1.4. Setup and Power On.......................................................................................................................................2-3
2.2. INCOMING INSPECTION.............................................................................................................................2-5
2.3. 6624CT-3000 FRONT VIEW...........................................................................................................................2-7
2.3.1. Power..............................................................................................................................................................2-7
2.3.2. Balance ...........................................................................................................................................................2-7
2.3.3. 3 A Burden......................................................................................................................................................2-7
2.3.4. 150 mA Burden ..............................................................................................................................................2-8
2.3.5. Range Switch..................................................................................................................................................2-8
2.4. 6624CT-3000 REAR VIEW.............................................................................................................................2-9
2.4.1. Line Input Connectors....................................................................................................................................2-9
2.4.2. Control Connector ..........................................................................................................................................2-9
2.4.3. DCCT-3000 Connector..................................................................................................................................2-9
2.4.4. CS1000 Connector..........................................................................................................................................2-9
3. QUICK MEASUREMENT GUIDE.............................................................................3-1
3.1. MEASUREMENT OPERATION GUIDE.....................................................................................................3-1
3.1.1. Current Measurement all Ranges...................................................................................................................3-1
3.1.2. Calculation of the Unknown Shunt Resistance..............................................................................................3-3
3.1.3. Recommended Test Setup Limits and Precautions for the 6624CT-3000 ....................................................3-3
3.1.4. Checks and Precautions..................................................................................................................................3-3
4. VERIFICATION AND CALIBRATION.......................................................................4-1
4.1. RATIO ACCURACY VERIFICATION........................................................................................................4-1
4.1.1. Purpose ...........................................................................................................................................................4-1

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4.2. TEST EQUIPMENT REQUIRED..................................................................................................................4-1
4.3. PROCEDURE....................................................................................................................................................4-2
4.3.1. Preliminary Connections to the 6624CT-3000 ..............................................................................................4-2
4.3.2. Measurement of the Potentials on the Resistors.............................................................................................4-2
4.3.3. Calculation of the Range Ratios.....................................................................................................................4-3
5. TROUBLESHOOTING AND MAINTENANCE .........................................................5-1
5.1. INTRODUCTION.............................................................................................................................................5-1
5.1.1. Model 6623A-3S Controller Fault Indications ..............................................................................................5-1
5.1.2. Maintenance....................................................................................................................................................5-1
6. APPENDICES...........................................................................................................6-1
6.1. GENERAL SPECIFICATIONS......................................................................................................................6-1
6.2. GENERAL SPECIFICATIONS (continued).................................................................................................6-2

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LIST OF FIGURES
FIGURE 1-1 : MODEL 6624CT-3000 BLOCK DIAGRAM......................................................................................1-3
FIGURE 2-1 : LINE VOLTAGE SELECTOR.............................................................................................................2-2
FIGURE 2-2 : 6624CT-3000 FRONT VIEW................................................................................................................2-7
FIGURE 2-3 : 6624CT-3000 REAR VIEW...................................................................................................................2-9
FIGURE 2-4 : 6624CT-3000 CONNECTIONS..........................................................................................................2-10
FIGURE 2-5 : 6624CT-3000 WITH PRIMARY CURRENT SHUNT CONNECTIONS.....................................2-11

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LIST OF TABLES
TABLE 2-1 : FUSE RATINGS.......................................................................................................................................2-2
TABLE 3-1 : 6624CT-3000 TEST SETUPS..................................................................................................................3-4
TABLE 6-1 : GENERAL SPECIFICATIONS.............................................................................................................6-1
TABLE 6-2 : GENERAL SPECIFICATIONS (CONTINUED).................................................................................6-2

Section 1
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1-1
1. INTRODUCTION
1.1. SCOPE
This document describes the installation, operation, specifications, maintenance and verification of
the 6624CT-3000 High Current DC Transformer. Precautions associated with high current
connections and measurements are provided for purposes of user safety and reliability.
1.2. GENERAL DESCRIPTION
The Model 6624CT-3000 High Current DC Transformer is designed to measure Direct Currents up
to a magnitude of 3000 amperes. The 6624CT-3000 is designed to be used with any current source;
however the 6624CT-3000 has additional built-in protection and safety features when used with
Guildline equipment. Specifically these protection and safety features are activated when the
6624CT-3000 is used in conjunction with Guildline CS1000 Current Sources and the 66259
Extender Control Unit; or when used with a Guildline 6622A DCC Bridge and the 6623A High
Current Range Extender. The direct current transformer is designed with an open window to pass
through a cable, set of cables, or buss bar that carry the current to be measured. The 6624CT-3000
High Current DC Transformer produces an output current that varies directly with the input current
in three ranges. By the connection of a reference shunt burden on one of the output terminals the
primary current can be deduced from the measured voltage on the reference shunt.
Switch selectable secondary windings provide transformation ratios of 100:1, 500:1, and 1,000:1;
and allow for measurements to be performed up to a maximum of 3000 amperes. The full scale
output range of 3 A is provided at a pair of binding post terminals on the front panel of the control
chassis. Three primary current ranges are provided, 300 A, 1500 A and 3000 A. A second pair of
binding post terminals is provided which provides an additional 20:1 reduction in the secondary
current such that a full scale output of 0.15 A is available for each primary range. A reference shunt
of 1 ohm or less is recommended for use as a burden.
The 6624CT-3000 High Current DC Transformer includes a 6623A-3S DC Current Transformer
Controller which provides for the modulation and demodulation of the DC flux in the Current
Transformer Unit. The 6623A-3S is normally mounted close to the current transformer through a
1.5m 12 conductor cable. The 6623A-3S also provides connections between CS1000 Current
Source Units and a Model 66259 Extender Control Unit or a 6622A DCC Bridge. The Model
66259 in combination with the CS1000 Current Source Units provides for primary DC currents
from 3 to 3000 A. The 6624CT-3000 High Current DC Transformer is pre-wired and configured
for operation at nominal power line voltages of 100, 120, 220 or 240 VAC.
All necessary interconnections for the control of the Guildline 6623A current source, the 6623A-3S
DC Current Transformer Controller and the 6624CT-3000 High Current DC Transformer are
provided such that no hardware reconfiguration is required over the full range of operation other
than the connection of the output current terminal to an appropriate reference burden.

Section 1
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1-2
1.3. OVERVIEW
The Model 6624CT-3000 High Current DC Transformer is a precision, fixed ratio, direct current
transformer based on the principle of the direct current comparator. Figure 1-1 illustrates the
instrument circuits in block diagram form. Connections to the Guildline CS1000 Current Source
Units and the Model 66259 Extender Control Unit are shown when it is desired to use these as the
current source. The precision programmable electronically switched 6623A current source is
controlled using the Model 66259 Extender Control Unit. The 6623A-3S DC Current Transformer
Controller is connected to the Current Transformer Unit with a twelve conductor cable with circular
connectors. The 6623A-3S also has two other connections for the Model 66259 Extender Control
Unit and the CS1000 current sources.
No adjustments of the 6624CT-3000 High Current DC Transformer are required for proper
operation, but the correct range must be manually selected on the Current Transformer Unit for one
of three specific full scale current ranges. Three full scale ranges are provided; 3000 A, 1500 A and
300 A with transformation ratios of 1000:1, 500:1 and 100:1 respectively.
1.4. PRINCIPLE OF OPERATION
The Direct Current Comparator is a multiple winding toroidal transformer device shown in Figure
1-1 in which the primary window carries the direct current input. Modulator and detector windings
are used for the detection of DC flux in the core. Switch selectable secondary windings of 100, 500
and 1000 turns provide the means to balance the ampere-turns in the transformer core. When the
primary and secondary ampere-turns are equal and opposite there is zero resultant DC flux in the
core. This balance condition can be detected by the flux detector circuit. The DC output of the
detector is proportional to ampere-turn imbalance. The presence of DC flux in the core due to
primary-secondary ampere-turns unbalance is indicated by the detector in both magnitude and
polarity.
The peak detector drives a servo circuit to provide correction current which maintains ampere-turn
balance in the core such that the ratio of input and output currents is exactly 100:1, 500:1 or 1000:1
depending on which range of operation is selected. The Model 66259 Extender Control Unit
provides a drive signal to the CS1000 programmable current sources as to allow test currents from
+/- 3 A to +/- 3000 A to be realized. This current is normally directed to the primary window of the
toroidal transformer. Refer to the 66259 Operation Manual for a description of the current source
control and safety features.
Note that the 6624CT-3000 can be operated with a non-Guildline current source. In this
configuration no connections are required to the 66259 Extender Control Unit or to the CS1000
Programmable Current Sources.

Section 1
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1-3
Figure 1-1 : Model 6624CT-3000 Block Diagram
Voltmeter
P1
P2
C1
C2
P1
P2
C1
C2
Current
Comparator
Toroid 3A
1000T
Ns
50T
Servo Amplifier
Demodulator
Slave PSU
Flux Detector
Magnetic
Modulator
6624CT-3000 Current Transformer
Current
Comparator
Toroid 3000A
1000T
500T (switchable)
100T
Ns
Servo Amplifier
Demodulator
Slave PSU
6623A-3S
Control Unit
1000A
Current Source
1000A
Current Source
1000A
Current Source
Nx
1T
P2
P1
C2
C1
Voltmeter
Voltmeter
Flux Detector
Magnetic
Modulator
66259
Programmable
Current Drive

Section 2
OM6624CT-3000-5-00
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2-1
2. INSTALLATION
2.1. PRELIMINARIES
Note that the Model 6624CT-3000 High Current DC Transformer includes a separate 6623A-3S
DC Current Transformer Control Unit. The 6624CT-3000 High Current DC Transformer is
connected to the 6623A-3S DC Current Transformer Control Unit with a 1.5 m cable. The 6623A-
3S is normally shipped set for 240 Volt, 50/60 Hz operation. If necessary the 6623A-3S can be set
for 100, 120 or 220 Volt, 50/60 Hz operation. The Model CS1000 Current Source Units and the
Model 66259 Extender Control Unit are options for providing a suitable current source for use with
the 6624CT-3000 system.
2.1.1. Unpacking
a. Remove the 6624CT-3000 High Current DC Transformer and the other items from
the shipping container to a suitable location.
b. The following items are included along with the current transformer and control
units.
i. Operation Manual (OM6624CT-3000)
ii. Two Spare Fuses 1 A, (T) (GPN 099-21000)
iii. Two Spare Fuses 2 A, (T) (GPN 099-22000)
iv. Three SCW Leads, 2 m (GPN 20236.04.02)
v. One 12 conductor 1.5 m connection cable (GPN# 31482-01-21)
vi. AC Line Cord (GPN# 250-04030)
vii. Two Shorting Links (GPN# 225-02090)
viii. Termination Connector (GPN# 31061-02-09)
ix. Extender Cable 2.0 m (GPN# 20212.04.02)
2.1.2. Power Voltage Selection
The 6623A-3S DC Current Transformer Controller Unit is shipped with the line input
voltage set to 240 V. The line input selector must be set to the correct line voltage and the
correct fuse must be installed before power is applied to the instrument. The settings
available are 100 V, 120 V, 220 V, and 240 V. Figure 2-1 details the line input voltage
selector settings and fuse requirements.
Where the molded plug on the line cord supplied with the instrument does not match the
local power outlet socket, the plug can be removed and replaced with one that does fit the
local service. The plug should be re-wired as follows:
Brown wire - Line input
Blue wire - Neutral input
Green/Yellow - Ground (safety)