Fluke 52120A User manual

February 2012
© 2012 Fluke Corporation. All rights reserved.Specifications are subject to change without notice.
All product names are trademarks of their respective companies.
52120A
Transconductance Amplifier
Users Manual

i
Table of Contents
Chapter Title Page
1 Introduction and Specifications......................................................... 1-1
Introduction........................................................................................................ 1-3
How to Contact Fluke ........................................................................................ 1-3
Safety Information ............................................................................................. 1-4
Symbols ......................................................................................................... 1-5
Protective Earth (Grounding) ........................................................................ 1-6
Instruction Manuals ........................................................................................... 1-6
52120A Getting Started Manual.................................................................... 1-6
52120A Users Manual................................................................................... 1-6
How to Unpack and Examine the Product......................................................... 1-7
Service Information ........................................................................................... 1-7
How to Place and Rack Mount the Product ....................................................... 1-7
Cooling Considerations...................................................................................... 1-7
How to Connect the Product to Mains Power.................................................... 1-8
Front-Panel Features .......................................................................................... 1-10
Rear-Panel Features ........................................................................................... 1-12
Input and Output Connections ........................................................................... 1-13
Input Terminals ............................................................................................. 1-13
Output Terminals........................................................................................... 1-14
Product Connection Cables................................................................................ 1-14
Safe Working Practice................................................................................... 1-15
How to Connect the Product to an External Circuit ...................................... 1-15
How to Disconnect the Product from an External Circuit............................. 1-15
Accessories ........................................................................................................ 1-15
General Specifications ....................................................................................... 1-16
Electrical Performance Limits ........................................................................... 1-16
Performance Specifications ............................................................................... 1-17
Operated within 6105A or 6100B Control Loop, Sine or
Harmonic Input (all current ranges) .............................................................. 1-17
Coverage factor k=2.58 (99 % confidence level)...................................... 1-17
Coverage factor k=2.00 (95 % confidence level)...................................... 1-18
Operated Stand Alone.................................................................................... 1-19
Coverage factor k=2.58 (99 % confidence level)...................................... 1-19
Coverage factor k=2.00 (95 % confidence level)...................................... 1-20

52120A
Users Manual
ii
52120A/COIL 3 KA 25-Turn Coil ................................................................ 1-21
52120A/COIL 6 KA 50-Turn Coil ................................................................ 1-21
2 Front-Panel Operation ........................................................................ 2-1
Introduction........................................................................................................ 2-3
Notes on Product Use ........................................................................................ 2-3
Accuracy........................................................................................................ 2-3
Potential Measurement Errors ....................................................................... 2-4
Leakage Paths............................................................................................ 2-4
Common-Mode Current ............................................................................ 2-4
External Voltage Connections................................................................... 2-6
Load Regulation ........................................................................................ 2-8
Product Operation Behavior .......................................................................... 2-8
Front-Panel Indicator Colors..................................................................... 2-8
Incompatible Key Selections..................................................................... 2-9
Status Indicators ........................................................................................ 2-9
Voltage Compliance Indictors ........................................................................... 2-10
Three Red LEDs Together or Product Self-Shutdown.............................. 2-10
How to Use the Product ..................................................................................... 2-10
Current Amplifier Operation ......................................................................... 2-10
Stand-alone Operation ................................................................................... 2-10
How to Setup Multiple Amplifiers .................................................................... 2-12
Greater than 120 Amps Operation................................................................. 2-12
Closed-Loop Operation ................................................................................. 2-14
Multi-Phase Current Outputs......................................................................... 2-17
How to Use the Accessory Coils with the Product ............................................ 2-19
Current/Hz Profile ......................................................................................... 2-19
Current Cable Connection ............................................................................. 2-19
Current Clamp Calibration ............................................................................ 2-19
Built-In Fan ................................................................................................... 2-19
3 Remote Operations ............................................................................. 3-1
Introduction........................................................................................................ 3-3
IEEE-488.2 Compliance .................................................................................... 3-3
How to Set the Bus Address .............................................................................. 3-3
Power On and *RST Conditions........................................................................ 3-4
SCPI Status Registers ........................................................................................ 3-4
Remote Commands............................................................................................ 3-5
Supported Common Commands.................................................................... 3-6
Supported SCPI Commands .......................................................................... 3-6
SCPI Command Summary ........................................................................ 3-7
52120A SCPI Command Details .............................................................. 3-8
6105A SCPI Command Details ................................................................ 3-11
Calibration and Adjustment Command Extensions....................................... 3-12
6105A *OPT? Command .............................................................................. 3-12
4 Operator Maintenance ........................................................................ 4-1
Introduction........................................................................................................ 4-3
How to Replace the Mains Input Fuse........................................................... 4-3
How to Clean the Air Filter ........................................................................... 4-3
How to Clean the Product.............................................................................. 4-4
Replaceable Parts............................................................................................... 4-4

Contents (continued)
iii
5 Calibration............................................................................................ 5-1
Introduction........................................................................................................ 5-3
Calibration Correction Factors ...................................................................... 5-3
Equipment Required ...................................................................................... 5-3
Initial Setup and Input Zero Adjustments...................................................... 5-3
Calibration Verification – Standalone Mode................................................. 5-5
Equipment Setup ....................................................................................... 5-7
2 Amp Range Verification ........................................................................ 5-7
20 Amp Range Verification ...................................................................... 5-9
120 Amp Range Verification .................................................................... 5-11
Current Input Burden Resistor Verification .............................................. 5-13
Amplitude Specification Limits, Pass/Fail Analysis ..................................... 5-13
Calibration Adjustment – Standalone Mode ................................................. 5-14
Equipment Set Up ..................................................................................... 5-14
How to Correct for Shunt Resistance Error .............................................. 5-16
Adjustment Process ................................................................................... 5-16
Adjustments Notes .................................................................................... 5-16
Adjustments .............................................................................................. 5-16
Calibration Verification – Closed-Loop with 6100A or 6105A.................... 5-22
Test Equipment ......................................................................................... 5-22
Power Line Frequency Confidence Check................................................ 5-22
Phase Angle Accuracy Confidence Check................................................ 5-23
Verify Amplitudes at DC and Higher Frequencies ................................... 5-23
Verify Phase Angles at Higher Frequencies ............................................. 5-26

52120A
Users Manual
iv

v
List of Tables
Table Title Page
1-1. Symbols.................................................................................................................. 1-5
1-2. Standard Equipment ............................................................................................... 1-7
1-3. Line Power Cord Types Available from Fluke ...................................................... 1-9
1-4. Front-Panel Features .............................................................................................. 1-10
1-5. Rear-Panel Features ............................................................................................... 1-12
1-6. Maximum Voltage and Current on Input Terminals .............................................. 1-13
1-7. Maximum Voltage and Current on Output Terminals ........................................... 1-14
1-8. Optional Accessories.............................................................................................. 1-15
2-1. Confidence Probabilities ........................................................................................ 2-3
2-2. Total Accuracy Calculation.................................................................................... 2-3
2-3. Front-Panel Indications .......................................................................................... 2-8
2-4. Status Indicators ..................................................................................................... 2-9
3-1. Power On and RST Defaults .................................................................................. 3-4
3-2. Common Command Summary............................................................................... 3-6
3-3. SCPI Commands .................................................................................................... 3-7
3-4. 6105A SCPI Commands for the 52120A............................................................... 3-8
3-5. *OPT? Bit Identification ........................................................................................ 3-12
4-1. Approved Replacement Fuses................................................................................ 4-3
4-2. Replaceable Parts ................................................................................................... 4-4
5-1. Calibration Equipment ........................................................................................... 5-3
5-2. Nominal Resistance for A40B Shunts.................................................................... 5-6
5-3. 2 Amp Range Verification ..................................................................................... 5-8
5-4. 20 Amp Range Verification Points ........................................................................ 5-10
5-5. 120 Amp Range Verification Points ...................................................................... 5-12
5-6. Burden Resistor Verification Points....................................................................... 5-13
5-7. Product Adjustment Points..................................................................................... 5-20
5-8. Test Equipment for Closed-Loop Verification....................................................... 5-22
5-9. Power Line Frequency Confidence Check Points.................................................. 5-23
5-10. Phase Angle Accuracy Confidence Check Points.................................................. 5-23
5-11. Amplitude Verification on 2 Amp Range .............................................................. 5-24
5-12. Amplitude Verification on 20 Amp Range ............................................................ 5-25
5-13. Amplitude Verification on 120 Amp Range .......................................................... 5-26
5-14. Phase Angle Verification on 2 Amp Range ........................................................... 5-26
5-15. Phase Angle Verification on 20 Amp Range ......................................................... 5-27
5-16. Phase Angle Verification on 120 Amp Range ....................................................... 5-27

52120A
Users Manual
vi

vii
List of Figures
Figure Title Page
1-1. Front-Panel View ................................................................................................... 1-10
1-2. Rear-Panel View .................................................................................................... 1-12
2-1. Connections for Reduced Common-Mode Interference ........................................ 2-5
2-2. Product Connections to a Watthour Meter............................................................. 2-7
2-3. Status Indicators ..................................................................................................... 2-9
2-4. 5520A and 52120A Connections ........................................................................... 2-11
2-5. Master to Slave Connections.................................................................................. 2-13
2-6. Two Amplifier Outputs Connected in Parallel....................................................... 2-14
2-7. Feedback Cable Connections ................................................................................. 2-15
2-8. Multiple Amplifier Connections ............................................................................ 2-16
2-9. 6105A to 6106A Connections ................................................................................ 2-18
3-1. IEEE Bus Address Switches .................................................................................. 3-3
3-2. SCPI Status Registers............................................................................................. 3-5
5-1. Test Equipment Connections ................................................................................. 5-4
5-2. Calibration Adjustment Setup ................................................................................ 5-15
5-3. Calibration Enable Switch...................................................................................... 5-16

52120A
Users Manual
viii

1-1
Chapter 1
Introduction and Specifications
Title Page
Introduction.......................................................................................................... 1-3
How to Contact Fluke .......................................................................................... 1-3
Safety Information ............................................................................................... 1-4
Symbols ........................................................................................................... 1-5
Protective Earth (Grounding) .......................................................................... 1-6
Instruction Manuals ............................................................................................. 1-6
52120A Getting Started Manual...................................................................... 1-6
52120A Users Manual..................................................................................... 1-6
How to Unpack and Examine the Product........................................................... 1-7
Service Information ............................................................................................. 1-7
How to Place and Rack Mount the Product ......................................................... 1-7
Cooling Considerations........................................................................................ 1-7
How to Connect the Product to Mains Power...................................................... 1-8
Front-Panel Features ............................................................................................ 1-10
Rear-Panel Features ............................................................................................. 1-12
Input and Output Connections ............................................................................. 1-13
Input Terminals ............................................................................................... 1-13
Output Terminals............................................................................................. 1-14
Product Connection Cables.................................................................................. 1-14
Safe Working Practice..................................................................................... 1-15
How to Connect the Product to an External Circuit ........................................ 1-15
How to Disconnect the Product from an External Circuit............................... 1-15
Accessories .......................................................................................................... 1-15
General Specifications ......................................................................................... 1-16
Electrical Performance Limits ............................................................................. 1-16
Performance Specifications ................................................................................. 1-17
Operated within 6105A or 6100B Control Loop, Sine or
Harmonic Input (all current ranges) ................................................................ 1-17
Coverage factor k=2.58 (99 % confidence level)........................................ 1-17
Coverage factor k=2.00 (95 % confidence level)........................................ 1-18
Operated Stand Alone...................................................................................... 1-19
Coverage factor k=2.58 (99 % confidence level)........................................ 1-19
Coverage factor k=2.00 (95 % confidence level)........................................ 1-20
52120A/COIL 3 KA 25-Turn Coil .................................................................. 1-21
52120A/COIL 6 KA 50-Turn Coil .................................................................. 1-21

52120A
Users Manual
1-2

Introduction and Specifications
Introduction 1
1-3
Introduction
The Fluke 52120A Transconductance Amplifier (the Product) is a precision current
amplifier that can:
•Accept full scale dc or ac inputs of 2 volts or 200 mA from any calibrator, signal
generator or power supply
•Deliver proportional output current in ranges of 2 A, 20 A or 120 A at frequencies to
10 kHz
•Offer enhanced accuracy to 140 ppm when used in closed-loop mode with a 6105A
Electrical Power Standard
•Operate in parallel with one or two other Products to deliver 240 A or 360 A
•Push current with compliance voltage of 4.5 V rms or 6.4 V peak
•Drive inductive loads to 1 mH
•Drive optional current coils to deliver test currents of 3000 A or 6000 A
How to Contact Fluke
To contact Fluke Calibration, call one of the following telephone numbers:
•Technical Support USA: 1-877-355-3225
•Calibration/Repair USA: 1-877-355-3225
•Canada: 1-800-36-FLUKE (1-800-363-5853)
•Europe: [phone]
•Japan: [phone]
•Singapore: [phone]
•China: [phone]
•Brazil: [phone]
•Anywhere in the world: [phone]
To see product information and download the latest manual supplements, visit Fluke
Calibration’s website at www.flukecal.com
To register your product, visit http://flukecal.com/register-product.

52120A
Users Manual
1-4
Safety Information
This Product complies with:
•EN/IEC 61010-1:2010
•CAN/CSA C22.2 No. 61010-1-04
•ANSI/UL 61010-1:2004
•EN 61326-1:2006
In this manual, a Warning identifies conditions and procedures that are dangerous to the
user. A Caution identifies conditions and procedures that can cause damage the Product
or the equipment under test.
For safe operation of this Product, follow all the warnings and cautions in this manual.
XW Warning
To prevent possible electrical shock, fire, or personal injury:
•Read all safety Information before you use the Product.
•Never connect line power to a Product input or output
connector, other than the mains power receptacle.
•Use this Product indoors only.
•Do not use the Product around explosive gas, vapor, or in
damp or wet environments.
•Examine the case before you use the Product. Look for
cracks or missing parts. Carefully look at the insulation
around the terminals.
•Use only the mains power cord and connector approved for
the voltage and plug configuration in your country and rated
for the Product.
•Make sure the ground conductor in the mains power cord is
connected to a protective earth ground. Disruption of the
protective earth could put voltage on the chassis that could
cause death.
•Replace the mains power cord if the insulation is damaged
or if the insulation shows signs of wear.
•Do not use and disable the Product if it is damaged.
•Be aware the 52120A binding posts may be connected to
supply lethal voltages. If one terminal of a pair is connected,
the other may also be at lethal potential.
•Do not energize voltage circuits unless the Product cables
are either properly connected at both ends or disconnected
at both ends.
•Use only cables with correct voltage ratings.
•Use extreme caution when the current output terminals of
the Product are connected to voltage circuits, as lethal
voltage may be present.

Introduction and Specifications
Safety Information 1
1-5
•Do not connect to live output terminals. The Product can
supply voltages that can cause death. Standby mode is not
sufficient to prevent electrical shock.
•Use the Product only as specified, or the protection
supplied by the Product can be compromised.
•Always ensure the Product is in STBY mode and external
circuits are not energized before you make cable
connections or disconnecting either end of the cables.
•Do not touch voltages >30 V ac rms, 42 V ac peak, or 60 V
dc.
•Do not use the Product if it operates incorrectly.
•Do not use test leads if they are damaged. Examine the test
leads for damaged insulation. Do a continuity test on the
test leads.
Symbols
Symbols used in this manual and on the Product are explained in Table 1.
Table 1-1. Symbols
Symbol Description Symbol Description
Chassis ground )Conforms to relevant North American
Safety Standards.
PConforms to European Union
directives. .Protective earth
WRisk of Danger. Important information.
See manual. XHazardous voltage
JEarth ground Conforms to relevant Australian EMC
requirements.
~Do not dispose of this product as unsorted municipal waste. Go to Fluke’s website for recycling
information.

52120A
Users Manual
1-6
Protective Earth (Grounding)
Protection Class 1 – Always operate the Product with an earth/ground connection to the
earth ground conductor of the ac supply cable. The earth/ground connects before the ac
line and neutral connections when the supply plug is put into the mains socket of the
Product. If the last mains connection is made elsewhere, make sure the earth/ground
connection is made before ac line and neutral.
Connect an applicable earth/ground to the auxiliary protective terminal on the rear panel
if:
•it is possible the earth/ground connection will not connect before the ac line and
neutral connections.
•the output terminals are connected to a potentially hazardous live circuit.
Instruction Manuals
The 52120A Manual set supplies complete information for operators. The set includes:
•52120A Users Manual on the included CD-ROM (PN 3977736)
•52120A Getting Started Manual (PN 3977724)
One of each manual shown above is shipped with the instrument. You can order more
copies of the manuals from Fluke. To learn more on how to place an order, refer to the
How to Contact Fluke section.
52120A Getting Started Manual
This 52120A Getting Started Manual contains a brief introduction to the Product. The
Getting Started topics are:
•Safety Information
•Instruction manuals and their content
•How to unpack and examine the Product
•How to connect the Product to mains power
•Front and rear panel familiarization
•Maintenance
•General Specifications
52120A Users Manual
The 52120A Users Manual contains data on how to install the Product and operate it
from the front panel keys and in remote configurations. This manual also contains
Product specifications and error codes. The Users Manual topics are:
•Installation
•Operating controls and features, including front panel controls
•Remote operation
•Operator maintenance
•Calibration
•Accessories

Introduction and Specifications
How to Unpack and Examine the Product 1
1-7
How to Unpack and Examine the Product
The Product is shipped in a container built to prevent damage during shipping. Examine
the Product carefully for damage and immediately report damage to the shipper.
Instructions for inspection and claims are included in the shipping container.
When you unpack the Product, make sure all the standard equipment shown in Table 2
was shipped. Also examine the shipping document for more items. Refer to the
Accessories chapter in the 52120A Users Manual. Report all shortages to the place of
purchase or to the nearest Fluke Service Center. A performance test is shown in the
Maintenance chapter in the 52120A Users Manual.
If it becomes necessary to ship the Product, use the container and inserts it was initially
shipped in, if possible. If it is not available, you can get a transit case from Fluke. This
container is applicable for most handling conditions, but gives less shock protection than
the initial shipping container.
Table 1-2. Standard Equipment
Item Model or Part Number
Transconductance Amplifier 52120A
Line Power Cord Per ship-to location, see Table 1-3.
52120A Getting Started Manual 3977724
52120A Users Manual on CD-ROM 3977736
Service Information
Each Product is warranted to the original purchaser for the period specified in the
warranty and starts on the date received. The warranty is found at the front of this
manual.
Factory authorized service and technical advice for the Product is available at Fluke
Service Centers. A complete list of service centers is available at www.flukecal.com.
XW Warning
To prevent possible electrical shock, fire, or personal injury,
have an approved technician repair the Product.
How to Place and Rack Mount the Product
Always operate the Product in controlled electromagnetic environments such as
calibration and measurement laboratories. Where rf transmitters, like mobile telephones
are not used.
This Product can be used on a bench-top or in a rack. The rack-mount kit must be ordered
separately from Fluke. See the How to Contact Fluke section in this manual.
Note
There must be sufficient space on the sides of the Product for sufficient air
flow.
Cooling Considerations
WCaution
The Product can overheat and become damaged if the area
around the air intake is too small, the intake air is too warm, or
the air filter becomes clogged.

52120A
Users Manual
1-8
To increase the life of the Product:
•Keep the area around the air filter a minimum of 4 inches from nearby walls or
rack enclosures.
•Keep the inlet and exhaust perforations on the sides of the Product clear of
blockages.
•Keep the air that goes in to the Product between 5 °C and 35 °C.
•Make sure exhaust from a different instrument is not pointed into the fan inlet.
•Clean the air filter at a maximum of 30 day intervals. More frequently if the
Product is operated in a dusty environment. See the Maintenance section of this
manual for instructions on how to clean the air filter.
How to Connect the Product to Mains Power
XW Warning
To prevent possible electrical shock, fire, or personal injury:
•Use only the mains power cord and connector approved for
the voltage and plug configuration in your country and rated
for the Product.
•Replace the mains power cord if the insulation is damaged
or if the insulation shows signs of wear.
•Make sure the ground conductor in the mains power cord is
connected to a protective earth ground. Disruption of the
protective earth could put voltage on the chassis that could
cause death.
•Do not disconnect or open the protective ground conductor
inside or outside the Product. An open ground conductor
can make the Product dangerous.
WCaution
When exposed to low temperatures for an extended time, such
as air travel or storage, condensation may form inside the
Product. To prevent damage to the Product, let it acclimate to
its environment out of its shipping container a minimum of one
hour before you connect it to mains power.
The Product automatically senses mains voltage between 100 and 240 volts. No line
voltage or fuse selection is necessary. See the Maintenance section to learn how to
replace the mains fuse.
Because the Product can pull more current than a standard 10 A IEC connector, the
Product has a 16 A power connector on the rear panel. A mains power cord with 16 A
capacity is also supplied with the Product. Table 1-3 is a list of power cord types
available from Fluke.

Introduction and Specifications
How to Connect the Product to Mains Power 1
1-9
Table 1-3. Line Power Cord Types Available from Fluke
Country Fluke Part Number
UK 1998167
Europe 1998171
Australia, New Zealand 920385
China 920431
USA, Japan 1998209
Other (no plug fitted) 1998211
Note
Typical maximum power requirement of the Product at 115 V is 1500 VA.
Make sure the mains supply outlet is rated for this load and has a grounded
three-prong outlet. Make sure the outlet ground connector is connected to
earth ground.
If a mains power cord is supplied without a mains connector, use the color codes below
when you connect a connector to the power cord.
Line = Brown
Neutral = Blue
Earth = green/yellow

52120A
Users Manual
1-10
Front-Panel Features
Table 1-4 is a list of front-panel controls and connections shown in Figure 1-1.
20A
120A ON
OFF VOLTS
AMPS
HIGH
LOW 2A
LOCAL
STBY
OPR
3V PK
300mA PK
MAX
HIGH CURRENT
OUTPUT
LOW CURRENT
OUTPUT
850V PK
MAX
850V PK
MAX
30A PK
7V PK
MAX
180A PK
7V PK
MAX
OUTPUT
TERMINALS RANGE
VOLTAGE
COMPLIANCE
MAX
OVER COMPLIANCE
MIN
STATUS
MASTER UNIT
SLAVE UNIT
REMOTE OVER TEMP
L2 PHASE
L1 PHASE L3 PHASE
N PHASE
INPUT
INPUT OVER RANGE
L COMP
POWER
10V PK
MAX
OPTION
POWER
OUTPUT
(12V DC)
52120A
TRANSCONDUCTANCE AMPLIFIER
HI
LO
HI
LO
HI
LO
43 6
78
913 1112161718
52
10
1
1415
gpp001.eps
Figure 1-1. Front-Panel View
Table 1-4. Front-Panel Features
Item Description
Current Output Indicators
Output on indicator. In STBY (standby) mode, these two indicators will be Amber. In OPR
(operate) mode, the indicator for the selected terminals will be illuminated green.
M
The OPR (Operate) key places the Product in operate mode. Operate mode is indicated by the lit
indicator on the OPR key. The indicator over the set output terminals also shows green.
Voltage Compliance Level Indicator
Over Compliance Indicator
Indicates when the Product senses the voltage developed across the current terminals due to the
current through the load impedance has exceeded the specified level. This condition also
automatically puts the Product in standby to remove the output current.
S
The STBY (Standby) key puts the Product in standby mode. Standby mode is indicated by the lit
indicator on the STBY key. The output indicators above the output terminals also shows amber.
Status Indicators
Indicates the status of the different functions of the Product.