Used Agilent Agilent Used U8002A Manual1,

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - TestEquipmentDepot.com

Keysight U8001A/U8002A
Single Output DC Power
Supplies

User’s and
Service Guide

Notices

CAUTION

WARNING

Copyright Notice

© Keysight Technologies 2008-2017
No part of this manual may be

reproduced in any form or by any
means (including electronic storage
and retrieval or translation into a
foreign language) without prior
agreement and written consent from
Keysight Technologies as governed by
United States and international
copyright laws.

Trademarks

Microsoft ® is a U.S. registered
trademark of Microsoft Corporation.

Manual Part Number

U8001-90001

Edition

Edition 8, September 2, 2017

Printed in:

Printed in Malaysia

Published by:

Keysight Technologies
Bayan Lepas Free Industrial Zone,
11900 Penang, Malaysia

Technology Licenses

The hardware and/or software
described in this document are
furnished under a license and may be
used or copied only in accordance with
the terms of such license.

Declaration of Conformity

Declarations of Conformity for this
product and for other Keysight
products
Web.

may be downloaded from the

U.S. Government Rights

The Software is “commercial computer
software,” as defined by Federal
Acquisition Regulation (“FAR”) 2.101.
Pursuant to FAR 12.212 and 27.405-3
and Department of Defense FAR
Supplement (“DFARS”) 227.7202, the
U.S. government acquires commercial
computer software under the same
terms by which the software is
customarily provided to the public.
Accordingly, Keysight provides
Software to U.S. government
customers under its standard
commercial license, which is embodied

its End User License Agreement

in
(EULA). The license set forth in the
EULA represents the exclusive
authority by which the U.S.
government may use, modify,
distribute, or disclose the Software.
The EULA and the license set forth
therein, does not require or permit,
among other things, that Keysight: (1)
Furnish technical

information related to commercial
computer software or commercial
computer software documentation that
is not customarily provided to the
public; or (2) Relinquish to, or
otherwise provide, the government
rights in excess of these rights
customarily provided to the public to
use, modify, reproduce, release,
perform, display, or disclose
commercial computer software or
commercial computer software
documentation. No additional
government requirements beyond
those set forth in the EULA shall apply,
except to the extent that those terms,
rights, or licenses are explicitly required
from all providers of commercial
computer software pursuant to the FAR
and the DFARS and are set forth
specifically in writing elsewhere in the
EULA. Keysight shall be under no
obligation to update, revise or
otherwise modify the Software. With
respect to any technical data as
defined by FAR 2.101, pursuant to FAR

12.211 and 27.404.2 and DFARS

227.7102, the U.S. government
acquires no greater than Limited Rights
as defined in FAR 27.401 or DFAR

227.7103-5 (c), as applicable in any
technical data.

the

Warranty

THE MATERIAL CONTAINED IN THIS
DOCUMENT IS PROVIDED “AS IS,”
AND IS SUBJECT TO BEING
CHANGED, WITHOUT NOTICE, IN
FUTURE EDITIONS. FURTHER, TO THE
MAXIMUM EXTENT PERMITTED BY
APPLICABLE LAW, KEYSIGHT
DISCLAIMS ALL WARRANTIES, EITHER
EXPRESS OR IMPLIED, WITH REGARD
TO THIS MANUAL AND ANY
INFORMATION CONTAINED HEREIN,
INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE. KEYSIGHT
SHALL NOT BE LIABLE FOR ERRORS
OR FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES IN
CONNECTION WITH THE
FURNISHING, USE, OR
PERFORMANCE OF THIS DOCUMENT
OR OF ANY INFORMATION
CONTAINED HEREIN. SHOULD
KEYSIGHT AND THE USER HAVE A
SEPARATE WRITTEN AGREEMENT
WITH WARRANTY TERMS COVERING
THE MATERIAL IN THIS DOCUMENT
THAT CONFLICT WITH THESE TERMS,
THE WARRANTY TERMS IN THE
SEPARATE AGREEMENT SHALL
CONTROL.

Safety Information

A CAUTION notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in damage to the product
or loss of important data. Do not
proceed beyond a CAUTION notice
until the indicated conditions are fully
understood and met.

A WARNING notice denotes a hazard. It
calls attention to an operating
procedure, practice, or the like that, if
not correctly performed or adhered to,
could result in personal injury or death.
Do not proceed beyond a WARNING
notice until the indicated conditions are
fully understood and met.

2 Keysight U8001A/U8002A User’s and Service Guide

Safety Symbols

The following symbols on the instrument and in the documentation indicate
precautions that must be taken to maintain safe operation of the instrument.

Direct current Off (supply)

Alternating current On (supply)

Both direct and alternating current

Three-phase alternating current Caution, risk of electric shock.

Earth (ground) terminal

Protective conductor terminal Caution, hot surface.

Equipment protected throughout by
double insulation or reinforced
insulation.

Caution, risk of danger (refer to this
manual for specific Warning or Caution
information.

Frame or chassis terminal

Equipotentiality In position of a bi-stable push control.

Out position of a bi-stable push
control.

Keysight U8001A/U8002A User’s and Service Guide 3

General Safety Information

WARNING

CAUTION

The following general safety precautions must be observed during all phases of
operation, service and repair of this instrument. Failure to comply with these
precautions or specific warnings elsewhere in this manual violates safety
standards of design, manufacture and intended use of the instrument. Keysight
Technologies assumes no liability for customer’s failure to comply with these
requirements.

– Do not use the device if it appears damaged or defective.

– Observe all markings on the device before connecting any wiring to the

device.

– Do not operate the device in the presence of flammable gases or fumes.

– Do not install substitute parts or perform any unauthorized modification

to the device.

– Use only the power adapter provided by the manufacturer to avoid any

unexpected hazards.

– Use the device with the cables provided.

– Repair or service that this not covered in this manual should only be

performed by qualified personnels.

4 Keysight U8001A/U8002A User’s and Service Guide

Environment Conditions

CAUTION

This instrument is designed for indoor use in an installation category II, pollution
degree 2 area. Table 1 shows general environment requirements.

Environment Conditions Requirements

Temperature

Operating Relative Humidity (max) Up to 95%

Altitude Up to 2000 m

The Keysight U8001A/U8002A single output DC power supplies comply with
the following safety and EMC requirements:

– IEC 61326:2002/EN61326:1997+ A1:1998+A3:2003

– CISPR 11:1990/EN55011:1990

– Canada: ICES-001:2004

– Australia/New Zealand: AS/NZS CISPR11:2004

– IEC 61010-1:2001/EN61010-1:2001 (2

Operating condition
0 °C to 40 °C (for full rated output)
40 °C to 55 °C (for derated output)
Storage condition
–20 °C to 70 °C

nd

Edition)

– Canada: CAN/CSA-C22.2 No. 61010-1-04

– USA: ANSI/UL 61010-1:2004

Keysight U8001A/U8002A User’s and Service Guide 5

Regulatory Markings

The CE mark is a registered trademark
of the European Community. This CE
mark shows that the product complies
with all the relevant European Legal
Directives.

ICES/NMB-001 indicates that this ISM
device complies with Canadian
ICES-001.

The CSA mark is a registered
trademark of the Canadian Standards
Association. A CSA mark indicates that
the product is certified for Canadian
markets, to the applicable Canadian
standards.

The RCM mark is a registered
trademark of the Australian
Communications and Media Authority.

This instrument complies with the
WEEE Directive (2002/96/EC) marking
requirement. This affixed product label
indicates that you must not discard
this electrical/electronic product in
domestic household waste.

6 Keysight U8001A/U8002A User’s and Service Guide

Waste Electrical and Electronic Equipment (WEEE) Directive 2002/96/EC

This instrument complies with the WEEE Directive (2002/96/EC) marking
requirement. This affixed product label indicates that you must not discard this
electrical or electronic product in domestic household waste.

Product category

With reference to the equipment types in the WEEE directive Annex 1, this
instrument is classified as a “Monitoring and Control Instrument” product.

The affixed product label is as shown below.

Do not dispose in domestic household waste.

Keysight U8001A/U8002A User’s and Service Guide 7

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

8 Keysight U8001A/U8002A User’s and Service Guide

Table of Contents

Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

General Safety Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Environment Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Regulatory Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Waste Electrical and Electronic Equipment (WEEE) Directive

2002/96/EC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Product category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Sales and Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

1Quick Start

Preliminary Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Output Checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Voltage output checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Current output checkout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

If the Power Supply Does Not Turn On . . . . . . . . . . . . . . . . . . . . . . . . .19

To Rack-mount the Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

2 General Information

Front Panel at a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Rear Panel at a Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Display Annunciators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Initial inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Cooling and location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Output Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Voltage drops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

3 Operations and Features

Constant Voltage Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Constant Current Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Keysight U8001A/U8002A User’s and Service Guide 9

Memory Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Programming Over Voltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . 38

Programming Over Current Protection . . . . . . . . . . . . . . . . . . . . . . . . . 41

Keylock Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Backlight Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

System Related Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Extending the Voltage and Current Range . . . . . . . . . . . . . . . . . . . . . . 46

Series connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Parallel connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4 Specifications and Characteristics

5Service Guide

Equipment Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Types of service available . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Repackaging for shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Line Voltage Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Orientation of the voltage selector AC inlet . . . . . . . . . . . . . . . . . . . 55

Self-Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Performance Verification and Calibration . . . . . . . . . . . . . . . . . . . . . . . 57

Recommended test equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Test consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Measurement techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Constant voltage (CV) verification . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Constant Current (CC) Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

Voltage Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Current Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

6Appendix

Appendix A: List of Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

10 Keysight U8001A/U8002A User’s and Service Guide

List of Figures

Figure 3-1 Recommended protection circuit for battery

Figure 5-1 Orientation of voltage selector AC inlet in different

Figure 5-2 Test setups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

Figure 5-3 General measurement . . . . . . . . . . . . . . . . . . . . . . . . .61

Figure 5-4 Graph of load transient response . . . . . . . . . . . . . . . .69

charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

voltage selection . . . . . . . . . . . . . . . . . . . . . . . . . . .55

Keysight U8001A/U8002A User’s and Service Guide 11

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

12 Keysight U8001A/U8002A User’s and Service Guide

List of Tables

Table 1-1 List of rated fuse for line voltages . . . . . . . . . . . . . . . .19

Table 5-1 Replaceable parts . . . . . . . . . . . . . . . . . . . . . . . . . . . .52

Table 5-2 List of equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Keysight U8001A/U8002A User’s and Service Guide 13

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

14 Keysight U8001A/U8002A User’s and Service Guide

Keysight U8001A/U8002A Single Output DC Power Supplies
User’s and Service Guide

1 Quick Start

Preliminary Checkout 16
Output Checkout 17
If the Power Supply Does Not Turn On 19
To Rack-mount the Instrument 20

This chapter is intended for both the experienced and inexperienced users
because it calls attention to certain checks that should be made prior to
operation.

15

1 Quick Start

NOTE

Preliminary Checkout

The following steps help you to validate that the power supply is ready for use.

1 Check the list of supplied item.

Verify that you have received the following items together with your power

supply. If anything is found missing, contact your nearest Keysight

Technologies Sales Office.

–Power cord

– Certificate of Calibration

– Product Reference CD-ROM

2 Connect the power cord and turn on the power supply.

The front-panel display will light up while the power supply performs its power-on
self-test. The firmware revision is also displayed. If the power supply does not turn
on properly, see page 19.

The power supply is shipped from the factory with a power- line cord that has a
plug approriate for your location. Your power supply is equipped with a 3- wire
grounding type power cord; the third conductor being the ground. The power
supply is grounded only when the power- line cord is plugged into an
appropriate receptacle. Do not operate your power supply without adequate
cabinet ground connection.

16 Keysight U8001A/U8002A User’s and Service Guide

Output Checkout

NOTE

NOTE

The following procedures check to ensure that the power supply develops its
rated outputs and properly responds to operation from the front panel. For
complete performance and verification tests, refer to the Service Guide.

If an error has been detected during the output checkout procedures, the ERROR
annunciator will be turned on. See Appendix A: List of Error Codes for more
information.

Voltage output checkout

The following steps verify basic voltage functions with no load.

1 Turn on the power supply.

The power supply is in a power-on / reset state; the output is disabled (the OFF
annunciator turns on).

2 Enable the outputs.

The OFF annunciator turns off. Notice that the display is in the meter mode.
“Meter mode” means that the display shows the output voltage and current
limit.

3 Check that the front-panel voltmeter properly responds to knob control.

4 Turn the knob clockwise or counter clockwise to check that the voltmeter

responds to knob control and the ammeter indicates nearly zero.

Quick Start 1

5 Ensure that the voltage can be adjusted from zero to the full rated value by

adjusting the knob.

When the power supply is turned on, the last memory will be shown on the
display.

Keysight U8001A/U8002A User’s and Service Guide 17

1 Quick Start

Current output checkout

The following steps check basic current functions with a short across the power
supply's output.

1 Turn on the power supply.

Make sure that the output is disabled. The OFF annunciator is on.

2 Connect a short across (+) and (–) output terminals with an insulated test lead.

Use a wire size sufficient to handle the maximum current (refer to the American

Wire Gauge standard).

3 Enable the output.

The CV or CC annunciator turns on depending on the resistance of the test

lead. Notice that the display is in the meter mode.

4 Adjust the voltage limit value to 1.0 volt.

Set the display to the limit mode. Adjust the voltage limit to 1.0 V to assure CC

operation. The CC annunciator will be turned on. To go back to normal mode,

press the key again or let the display time out after several seconds.

5 Set the knob to the current control to check that the front-panel ammeter

properly responds to knob control.

Turn the knob clockwise or counter clockwise when the display is in the meter

mode (the Limit annunciator is off). Check that the ammeter responds to knob

control and the voltmeter indicates nearly zero (the voltmeter will show the

voltage drop caused by the test lead).

6 Ensure that the current can be adjusted from zero to the full rated value.

7 Turn off the power supply and remove the short from the output terminals.

18 Keysight U8001A/U8002A User’s and Service Guide

If the Power Supply Does Not Turn On

Use the following steps to help solve problems you might encounter when turning
on the instrument. If you need more help, refer to Chapter 5 for instructions on
returning the instrument to Keysight Technologies for service.

1 Verify that there is AC power to the power supply.

First, verify that the power cord is firmly plugged into the power receptacle on
the rear panel of the power supply. You should also make sure that the power
source you plugged the power supply into is energized. Then, verify that the
power supply is turned on.

2 Verify the power-l ine voltage setting.

The line voltage is set to the proper value for your country when the power
supply is shipped from the factory. Change the voltage setting if it’s not
correct. The settings are: 100, 115, or 230 Vac.

3 Verify that the correct power-line fuse is installed.

The correct fuse is installed for your country when the power supply is shipped
from the factory. See the table below to replace the fuse for your power supply.

Quick Start 1

Tab le 1-1 List of rated fuse for line voltages

Model Part number Part description

U8001A 2110-0014

2110-0006

U8002A 2110-0722

2110-1425

Fuse 4.0 A T for 100 and 115 Vac
Fuse 2.0 A T for 230 Vac

Fuse 6.25 A T for 100 and 115 Vac
Fuse 2.8 A T for 230 Vac

Keysight U8001A/U8002A User’s and Service Guide 19

1 Quick Start

To Rack-mount the Instrument

You can mount the power supply in a standard 19-inch rack cabinet using one of
three optional kits available. Instructions and mounting hardware are included
with each rack-mounting kit.

To rack-mount a single instrument, order adapter kit 5063-9240.

To rack-mount two instruments side-by-side, order lock-link kit, 5061-9694 and
flange kit, 5063-9212. Be sure to use the support rails inside the rack cabinet.

To install two instruments in a sliding support shelf, order support shelf,
5063-9255, and slide kit, 1494-0015.

20 Keysight U8001A/U8002A User’s and Service Guide

Keysight U8001A/U8002A Single Output DC Power Supplies
User’s and Service Guide

2 General Information

Front Panel at a Glance 22
Rear Panel at a Glance 23
Display Annunciators 24
Description 25
Installation 27
Output Connections 29

This chapter provides general description of the instrument, front panel overview,
rear panel overview, display annunciators and installation guidelines for U8001A/
U8002A single output DC power supplies.

21

2 General Information

1

2

4

5

6

8

7

3

9

11

12

13

10

Front Panel at a Glance

Panel s Functions

1 LCD Display Displays the measurements.

2 Memory To set the memory settings, enables memory recall and memory state selection (M1, M2, M3).

3 CAL Enables voltage and current calibration.

4 Back Light To turn On/Off the backlight.

5 Lock / Unlock Enables and disables the front panel operation.

6 Over Voltage Enables and disables the over voltage protection function, sets trip voltage and clears the over

voltage condition.

7 Over Current Enables and disables the over current protection function, sets trip current and clears the over

current condition.

8 Display Limit Displays and sets the voltage and current limit values.

9 Voltage / Current Selects the knob control function for voltage and current adjustment.

10 Output On/Off Enables and disables the power supply output.

11 Knob Increases and decreases the value of the flashing digit.

12 Power On/Off To turn On/Off the power supply.

13 Binding posts Positive, negative and ground binding posts for wire connections.

22 Keysight U8001A/U8002A User’s and Service Guide

Rear Panel at a Glance

1

2

3

4

5

Panel s Functions

1 AC inlet Connects AC power line.

General Information 2

2 Power fuse-holder assembly Sets the line voltage to the proper values for different country based.

3 Power-line module Combination of the AC inlet and power fuse-holder assembly.

4 Physical lock mechanism Enables physical lock mechanism.

5 Line Voltage Fuse Rating indicator Indicates the line voltage and line fuse rating.

Keysight U8001A/U8002A User’s and Service Guide 23

2 General Information

Constant Current

OFF

Constant Voltage

Memory State 1

Memory State 2

Memory State 3

Over voltage Protection

Over current Protection

Limit

LOCK

Display Annunciators

Annunciators Functions

M1
M2
M3

OVP The over voltage protection function is enabled when the annunciator turns on or the over voltage

Stores states of power supply in non-volatile memory.
When the power supply is in calibration mode, it can be used to store calibration constant.

protection circuit has caused the power supply to shutdown when the annunciator blinks.

OCP The over current protection function is enabled when the annunciator turns on or the over current

protection circuit has caused the power supply to shutdown when the annunciator blinks.

LOCK The front panel operation is disabled.

LIMIT The display shows the limit values of voltage and current.

OFF The output of the power supply is disabled.

CV The power supply is in constant voltage mode when the annunciator blinks.

CC The power supply is in constant current mode when the annuciator blinks.

24 Keysight U8001A/U8002A User’s and Service Guide

Description

General Information 2

The Keysight U8001A/U8002A single output DC power supplies are compact,
general purpose bench supplies that are suitable for either bench or
rack-mounted operations. These power supplies feature linear power supply
performance and capable usabilities, making them ideal for power systems
applications.

Operational features include:

– Single-output

– Constant voltage (CV) or constant current (CC) operation

– Over voltage protection (OVP) and Over current protection (OCP)

– Three storage locations (M1 to M3) for user-defined operating states

– Keypad lock capability

– Physical lock mechanism

The front panel operation permits:

– Easy-to-use control features

– Enabling or disabling OVP and OCP

– Setting the OVP and OCP trip levels

– Clearing OVP and OCP conditions

– Setting and displaying the voltage and current limit values

– Operating state storage/recall

– Resetting the power supply to power-on state

– Calibrating the power supply

– Enabling or disabling the output

Keysight U8001A/U8002A User’s and Service Guide 25

2 General Information

WARNING

The front-panel liquid crystal display (LCD) includes:

– Displaying actual values of output voltage and current (meter mode)

– Or displaying the limit values of voltage and current (limit mode)

– Checking the operating status from the annunciators

Front panel binding posts are available to connect load wires for bench
operation.

Floating the power supply output more than ±240 Vdc from the chassis
presents an electric shock hazard to the operator.

26 Keysight U8001A/U8002A User’s and Service Guide

Installation

Initial inspection

General Information 2

When you receive your power supply, inspect it for any obvious damage that may
have occurred during shipment. If any damage is found, notify the carrier and the
nearest Keysight Technologies Sales Office immediately. Warranty information is
shown in the front of this manual.

Keep the original packing materials in case the power supply has to be returned to
Keysight Technologies in the future. If you return the power supply for service,
attach a tag identifying the owner and model number. Also include a brief
description of the problem.

Mechanical check

This check confirms that there are no broken terminals or knob and that the
cabinet and panel surfaces are free of dents and scratches. Verify that the display
is not scratched or cracked.

Electrical check

Chapter 1 describes quick operation procedure that verifies to a high level of
confidence that the power supply is operating in accordance with its
specifications. More complete verification procedures are included in the “Service

Guide” on page 49.

Keysight U8001A/U8002A User’s and Service Guide 27

2 General Information

Cooling and location

Cooling

The power supply can operate at rated specifications within the temperature
range of 0 °C to 40 °C. Power supply loading is derated from 40 °C to 55 °C. A fan
cools the power supply by drawing air through the sides and exhausting it out the
back. Using a Keysight rack-mount will not impede the flow of air.

Bench operation

Your power supply must be installed in a location that allows sufficient space at
the sides and rear of the power supply for adequate air circulation.

Cleaning

No cleaning is required for this product. If you wish to remove dust from the
enclosure, use a dry cloth.

28 Keysight U8001A/U8002A User’s and Service Guide

Output Connections

WARNING

Before attempting to connect wires to the front output terminals, make sure
to turn off the power supply first to avoid damage to the circuits being
connected.

Voltage drops

The load wires must be large enough to avoid excessive voltage drops due to the
impedance of the wires. In general, if the wires are heavy enough to carry the
maximum short circuit current without overheating, excessive voltage drops will
not be a problem. The voltage drops across the load wires should be limited to
less than 2 V. Refer to the American Wire Gauge (AWG) standard to calculate the
voltage drop for some commonly used AWG wire copper.

General Information 2

Keysight U8001A/U8002A User’s and Service Guide 29

2 General Information

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

30 Keysight U8001A/U8002A User’s and Service Guide

Keysight U8001A/U8002A Single Output DC Power Supplies
User’s and Service Guide

3 Operations and Features

Constant Voltage Operation 32
Constant Current Operation 34
Memory Operations 36
Programming Over Voltage Protection 38
Programming Over Current Protection 41
Keylock Operation 43
Backlight Operation 44
System Related Operations 45
Extending the Voltage and Current Range 46

You have now learned how to install the power supply. You were also briefly
introduced to the front panel keys and their functionality from previous chapter.
This chapter shows you the operations and features for the U8001A/U8002A
single output DC power supplies.

31

3 Operations and Features

NOTE

Constant Voltage Operation

The following steps show you how to perform the constant voltage (CV)
operation.

1 Turn on the power supply.

– Press on the “Power” button to turn on the power supply. The power supply

will then perform a self-test (Self-test is not indicated at display).

– The display turns on all segments and shows the firmware version briefly

after that.

– The output is disabled by default.

– The OFF annunciator turns on.

– The display shows “OFF”

2 Set the d isplay to the limit mode.

– Press on the “Display Limit” button in order to turn on the LIMIT

annunciator.

– The display will show the voltage and current limit values.

When you press on the Display Limit button, the voltage and current limit values
will be shown on the display for about five seconds. If there is no activity
detected, the display will return to meter view mode.

3 Ad just for the desired output voltage.

– Press on the “Voltage/Current” button. When seeing the voltage value, “V”

blinks, turn the knob to adjust for the desired output voltage value.

32 Keysight U8001A/U8002A User’s and Service Guide

Operations and Features 3

NOTE

4 Ad just for the desired current l imit.

– Press on the “Voltage/Current” button. When seeing the current value, “A”

blinks, turn the knob to adjust for the desired current limit value.

5 Return to the meter mode.

– Press on the “Display Limit” button to return to the meter mode. The LIMIT

annunciator will be turned off.

6 Enable the output.

– Press on the “Output On/Off” button to enable the output.

– The OFF annunciator turns off and CV annunciator turns on.

– The display is now in meter mode.

Verify that the power supply is in constant voltage mode. Ensure that the
constant voltage (CV) annunciator is on. If the constant current (CC) annunciator
is on instead, choose a higher current limit.

Keysight U8001A/U8002A User’s and Service Guide 33

3 Operations and Features

NOTE

Constant Current Operation

The following steps show you how to perform the constant current operation.

1 Short the bind ing posts.

– Press on the “Power” button to turn off the power supply.

– Connect a short circuit between the positive (+) and negative (—) binding

posts.

2 Turn on the power supply.

– Press on the “Power” button to turn on the power supply. The power supply

will then perform a self-test.

– The display turns on all segments and shows the firmware version briefly

after that.

– The output is disabled by default.

– The OFF annunciator turns on.

3 Set the d isplay to the limit mode.

– Press on the “Display Limit” button in order to turn on the LIMIT

annunciator.

– The display will show the voltage and current limit values.

When you press on the Display Limit button, the voltage and current limit values
will be shown on the display for about five seconds. If there is no activity
detected, the display will return to meter view mode.

4 Ad just for the desired voltage limit.

– Press on the “Voltage/Current” button. When seeing the voltage value, “V”

blinks, turn the knob to adjust for the desired voltage limit value.

34 Keysight U8001A/U8002A User’s and Service Guide

Operations and Features 3

NOTE

5 Ad just for the desired output current.

– Press on the “Voltage/Current” button. When seeing the current value, “A”

blinks, turn the knob to adjust for the desired output current value.

6 Return to the meter mode.

– Press on the “Display Limit” button to return to the meter mode. The LIMIT

annunciator will be turned off.

7 Enable the output.

– Press on the “Output On/Off” button to enable the output.

– The OFF annunciator turns off and constant current (CC) annunciator turns

on.

– The display is now in meter mode.

Verify that the power supply is in constant current mode. Ensure that the
constant current (CC) annunciator is on. If the constant voltage (CV) annunciator
is on instead, choose a higher voltage limit.

Keysight U8001A/U8002A User’s and Service Guide 35

3 Operations and Features

NOTE

Memory Operations

For Keysight U8001A/U8002A single output DC power supplies, up to three
operating states can be stored in non-volatile storage locations. The storage

feature remembers the voltage and current limit value settings, OVP
On/Off states, and OVP/OCP trip levels. The following steps show you how to
store and recall an operating state.

Storing Operating State

1 Press on the “Memory” button.

– The M1 annunciator will blink.

2 Turn the knob to choose the memory location for storing the operation

state.

– The M1, M2 and M3 annunciators will blink in a round-robin manner.

3 Press on the “Memory” button again to save the operating state in the

chosen memory.

– Display will show “donE”.

– The M1, M2 and M3 annunciators will be turned off.

[1]

/OCP

[2]

To cancel the operation, allow the unit to idle for five seconds.

[1] OVP- over voltage protection

[2] OCP- over current protection

36 Keysight U8001A/U8002A User’s and Service Guide

Operations and Features 3

NOTE

Recalling operating state

1 Press and hold the “Memory” button.

– The M1 annunciator will be turned on.

– The LIMIT annunciator will be turned off.

– The display shows the settings saved in M1 memory location.

2 Turn the knob to show the settings saved in M1, M2 and M3 memory

locations.

– The M1, M2 and M3 annunciators will be turned on in round-robin manner.

3 Press on the “Memory” button if you want to use the shown settings as the

current operating settings

– The M1, M2 and M3 annunciators will be turned off.

To cancel the operation, allow the unit to idle for five seconds.

Keysight U8001A/U8002A User’s and Service Guide 37

3 Operations and Features

NOTE

Programming Over Voltage Protection

Over voltage protection guards the load against output voltages reaching values
greater than the programmed protection level.

The following steps show how to enable and disable the over voltage protection
(OVP), how to set the OVP trip level and how to clear the over voltage condition.

To set the OVP trip level and enable OVP

1 Press on the “Over Voltage” button.

– The LIMIT annunciator will be turned off.

– The OVP annunciator will fast-blink continuously.

– The display will show the OVP value and the character “V” will fast-blink

continuously.

2 Turn the knob to ad just the OVP value.

3 Press on the “Over Voltage” button again to end the ad justment and enable

the OVP.

– Display will show “donE”.

– The OVP annunciator will be turned on.

To cancel the operation, allow the unit to idle for five seconds.

38 Keysight U8001A/U8002A User’s and Service Guide

Operations and Features 3

NOTE

NOTE

To disable OVP

1 Press on the “Over Voltage” button to disable the OVP. The OVP annunciator

will eventually turn off.

To clear the over voltage condition

1 OVP trip can only occur when the output is enabled. When the OVP condition

occurs:

– The output is disabled and the OFF annunciator will be turned on.

– If the keylock feature was enabled, it will be disabled. The LOCK annuciator

will be turned off.

– The OVP annunciator will fast-blink continuously.

– The display will show “TRIP”.

2 To clear the OVP trip conditon, press on the “Over Voltage” button again.

If OVP trip persists, decrease the voltage limit settings to clear the tripping.

The power supply’s OVP circuit contains a crowbar SCR, which effectively shorts
the output of the power supply whenever the overvoltage condition occurs. If an
external voltage source such as a battery is connected across the output, and
the overvoltage condition inad vertently occurs, the SCR will continuously sink a
large current from the source and possibly damaging the power supply. To avoid
this, a diode must be connected in series with the output as shown in Figure 3-1.

Keysight U8001A/U8002A User’s and Service Guide 39

3 Operations and Features

Figure 3-1 Recommended protection circuit for battery charging

40 Keysight U8001A/U8002A User’s and Service Guide

Programming Over Current Protection

NOTE

Over current protection guards the load against output currents reaching values
greater than the programmed protection level.

The following steps show how to enable and disable the over current protection
(OCP), how to set the OCP trip level and how to clear the over voltage condition.

To set the OCP trip level and enable OCP

1 Press on the “Over Current” button.

– The LIMIT annunciator will be turned off.

– The OCP annunciator will fast-blink continuously.

– The display will show the OCP value and the character “A” will fast-blink

continuously.

2 Turn the knob to ad just the OCP value.

3 Press on the “Over Current” button again to end the adjustment and enable

the OCP.

– Display will show “donE”.

– The OCP annunciator will be turned on.

Operations and Features 3

To cancel the operation, allow the unit to idle for five seconds.

Keysight U8001A/U8002A User’s and Service Guide 41

3 Operations and Features

NOTE

To disable the OCP

1 Press on the “Over Current” button to disable the OCP. The OCP annunciator

will eventually turn off.

To clear the over current condition

1 OCP trip can only occur when the output is enabled. When the OCP condition

occurs:

– The output is disabled and the OFF annunciator will be turned on.

– If the keylock feature was enabled, it will be disabled. The LOCK annuciator

will be turned off.

– The OCP annunciator will fast-blink continuously.

– The display will show “TRIP”.

2 To clear the OCP trip conditon, press on the “Over Current” button again.

If OCP trip persists, decrease the current limit settings to clear the tripping.

42 Keysight U8001A/U8002A User’s and Service Guide

Keylock Operation

This operation provides locking function for the knob and all the buttons on front
panel of the equipment which allows end users to secure their desired settings.

The keylock is disabled by default when power-up.

To enable keylock

1 Press on the “Lock/Unlock” button. The LOCK annunciator will be turned on.

2 When the keylock function is enabled, the knob and all the buttons are

disabled EXCEPT “Lock/Unlock” button.

To disable keylock

1 Press and hold down the “Lock/Unlock” button for three seconds.

2 When the “Lock/Unlock” button is being held down, the display will show

“HOLD” until the keylock is disabled.

3 After the keylock is disabled, the LOCK annunciator will be turned off.

Operations and Features 3

Keysight U8001A/U8002A User’s and Service Guide 43

3 Operations and Features

Backlight Operation

This operation provides the backlight for the LCD display. The backlight will be
enabled by default when power-up.

To turn on the backlight

1 Press on the “Back Light” button. The backlight will be turned on.

To turn off the backlight

1 Press on the “Back Light” button. The backlight will be turned off.

44 Keysight U8001A/U8002A User’s and Service Guide

System Related Operations

NOTE

Reset to factory defaults

To reset the power supply unit to factory defaults, press and hold “Output On/Off”
button when power-up.

– The OVP and OCP are turned off and their values are set to maximum.

– The memory storage locations are cleared

– The voltage and current limit values are set to zero.

– The calibration values are intact.

Power-on self-test

A power-on self-test occurs automatically when the power supply unit is turned
on. This test ensures the unit is operational. The power-on self-test checks for
flash data memory and checks the voltage and current outputs when the unit is
off.

If the test fails, the display will show “Err” with the error code. See Appendix A:

List of Error Codes for more information.

Operations and Features 3

.

Keysight U8001A/U8002A User’s and Service Guide 45

3 Operations and Features

Extending the Voltage and Current Range

Two or more power supplies can be connected in series or parallel to extend the
range of voltage and current. This may serve as a lower cost alternative to a
power supply with higher power rating.

Series connection

Serial connection of two or more power supplies can achieve the output isolation
rating of any one supply to obtain a higher voltage than a single power supply.
Power supplies connected in series can be operated with one load across both
power supplies or with a separate load for each power supply. The power supply
has a diode with reverse polarity connected across the output terminals to avoid
any damages when operated in series with other power supplies. It will be
protected if the load is short-circuited, or when one of the power supply is turned
on separately in a series-connected power supplies.

When serial connection is used, the output voltage is the sum of output voltage
across all power supplies, while the output current is the output current from an
individual power supply. Each power supply must be adjusted to obtain the total
output voltage.

Parallel connection

Two or more power supplies which are capable of constant voltage or constant
current automatic cross-over operation can be connected in parallel to obtain a
total output current greater than one power supply. Total output current is the
sum of output current across all power supplies. The output settings from each
power supply can be made separately. The control of output voltage for one of the
power supply should be set to the desired output value, while the other power
supply should be set to a slightly higher output voltage. The power supply with
higher output voltage setting will deliver its constant current output and drop its
output voltage. This will happen until the output voltage equals the output of the
other supply, and the other supply will remain in constant voltage operation; only
delivering that fraction of rated output current that is necessary to fulfill the total
load demand.

46 Keysight U8001A/U8002A User’s and Service Guide

Keysight U8001A/U8002A Single Output DC Power Supplies
User’s and Service Guide

4 Specifications and

Characteristics

For the Specifications and Characteristics of the U8001A/U8002A Single Output
DC Power Supplies, refer to the datasheet at

http://literature.cdn.keysight.com/litweb/pdf/5989-7182EN.pdf.

47

4 Specifications and Characteristics

THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.

48 Keysight U8001A/U8002A User’s and Service Guide

Keysight U8001A/U8002A Single Output DC Power Supplies
User’s and Service Guide

5 Service Guide

Equipment Warranty 50
Replacement Parts 52
Troubleshooting 53
Line Voltage Conversion 54
Performance Verification and Calibration 57
Constant Current (CC) Verification 70
Voltage Calibration 75
Current Calibration 77

This chapter contains service information for the U8001A/U8002A single output
DC power supplies, including warranty information, general diassemble,
verification steps to troubleshoot the connectivity and functionality, detailed
calibration procedures for your power supply, related documentation and Keysight
contacts.

It is advised that you perform the calibration test before you start using the power
supply. The step-by-step calibration procedures are simple and easy to
understand. It is meant for both experienced and new users.

49

5 Service Guide

Equipment Warranty

Types of service available

If your instrument fails during the warranty period, Keysight Technologies will
replace it under the terms of your warranty. After your warranty expires, Keysight
offers repair by unit exchange service at competitive prices.

Extended service contracts

Many Keysight products are available with optional service contracts that extend
the covered period after the standard warranty expires. If you have such a service
contract and your instrument fails during the covered period, Keysight
Technologies will replace it in accordance with the contract.

50 Keysight U8001A/U8002A User’s and Service Guide

Repackaging for shipment

If the unit is to be shipped to Keysight for service or repair, be sure to:

– Attach a tag to the unit identifying the owner and indicating the required

service or repair. Include the model number and full serial number.

– Place the unit in its original carton with appropriate packaging material for

shipping.

– Secure the container with strong tape or metal bands.

– If the original shipping container is not available, place your unit in a container

which will ensure at least 4 inches of compressible packaging material around
all sides for the instrument. Use static-free packaging materials to avoid
additional damage to your unit.

Keysight suggests that you always insure your shipments.

Cleaning

No cleaning is required for this product. If you wish to remove dust from the
enclosure, use a dry cloth.

Service Guide 5

Keysight U8001A/U8002A User’s and Service Guide 51

5 Service Guide

Replacement Parts

This section contains information for ordering replacement parts for your
instrument. The parts lists are divided into the following sections.

– Parts are listed in alphanumeric order according to their reference designators

– The parts lists include a brief description of each part with applicable Keysight

part number.

To order replaceable parts

You can order replaceable parts from Keysight using the Keysight part number.
Note that not all parts listed in this chapter are available as field–replaceable
parts. To order replaceable parts from Keysight, do the following:

1 Contact your nearest Keysight Sales Office or Service Center.

2 Identify the parts by the Keysight part number shown in the replaceable parts

list.

3 Provide the instrument model number and serial number.

Tab le 5- 1 Replaceable parts

Part number Description

2110-0014 Fuse 4.0 A T for 100 Vac and 115 Vac (U8001A)

2110-0006 Fuse 2.0 A T for 230 Vac (U8001A)

2110-0722 Fuse 6.25 A T for 100 Vac and 115 Vac (U8002A)

2110-1425 Fuse 2.8 A T for 230 Vac (U8002A)

52 Keysight U8001A/U8002A User’s and Service Guide

Troubleshooting

This section provides a brief check list of common failures. Before troubleshooting
or repairing the power supply, make sure that the failure is in the instrument
rather than any external connections. Also make sure that the instrument is
accurately calibrated.

Unit is inoperative

– Verify that the AC power cord is connected to the power supply.

– Verify that the front-panel power switch is at “ON” position.

– Verify the power-line voltage setting.

– Verify that the power-line fuse is installed:

Model Part number Part description

Service Guide 5

U8001A 2110-0014

2110-0006

U8002A 2110-0722

2110-1425

Fuse 4.0 A T for 100 Vac and 115 Vac
Fuse 2.0 A T for 230 Vac

Fuse 6.25 A T for 100 Vac and 115 Vac
Fuse 2.8 A T for 230 Vac

Keysight U8001A/U8002A User’s and Service Guide 53

5 Service Guide

WARNING

1 Remove the power cord and

slide the fuse cover upwards

2 Pull the fuse plunger to remove

the fuse from the fuse holder

3 Remove the voltage selector

PCB using a flat-blade
screwdriver.

4 Replace the correct fuse and

orientate the PCB based on the
correct voltage.

Line Voltage Conversion

Shock Hazard. Operating personnel must not remove power supply covers.
Component replacement and internal adjustment must be made only by
qualified service personnel.

Line voltage conversion is accomplished by adjusting two components: the line
voltage selection switch and the power-line fuse on the rear panel.

54 Keysight U8001A/U8002A User’s and Service Guide

Orientation of the voltage selector AC inlet

100 indication needs to be in this
orientation

115 indication needs to be in this
orientation

230 indication needs to be in this
orientation

115 V

230 V

100 V

Service Guide 5

Figure 5-1 Orientation of voltage selector AC inlet in different voltage

selection

Keysight U8001A/U8002A User’s and Service Guide 55

5 Service Guide

Line Voltage Fuse Rating
indicator for U8001A

Line Voltage Fuse Rating
indicator for U8002A

NOTE

The authorised personnel will mark the fuse rating indicator printed on the rear
panel each time the fuse is changed.

Self-Test Procedures

Power-on self-test

Each time the power supply is powered on, a set of self-tests are performed.
These tests check that the minimum set of logic and measurement hardware are
functioning properly.

Unit fails self-test

Verify that the correct power-line voltage setting is selected. Also, ensure that all
terminal connections are removed while the self-test is performed. Please refer to

Appendix A: List of Error Codes for list of error codes.

56 Keysight U8001A/U8002A User’s and Service Guide

Performance Verification and Calibration

This chapter contains performance verification and calibration procedures. The
performance verification procedures allow you to verify that the power supply is
operating within its published specifications. The calibration procedures show
how to make voltage and current adjustment on the power supply.

Keysight Technologies calibration services

When your instrument is due for calibration, contact your local Keysight Service
Center for a low-cost recalibration.

Calibration interval

One year interval is recommended for most applications. Accuracy specifications
are warranted only if calibration is made at regular calibration interval. Accuracy
specifications are not warranted beyond the one year calibration interval. Keysight
does not recommend extending calibration intervals beyond two years for any
application. Keysight recommends that complete re-adjustment should always be
performed at the calibration interval. This will increase your confidence that the
U8001A and U8002A will remain within specification for the next calibration
interval. The re-adjustment provides the best long-term stability and accuracy.

Service Guide 5

Keysight U8001A/U8002A User’s and Service Guide 57

5 Service Guide

Recommended test equipment

The test equipment recommended for the calibration and adjustment is listed
below. If the exact instrument is not available, substitute the calibration standards
of equivalent requirement(s).

Tab le 5- 2 List of equipment

Equipment Requirement(s) Recommended model Purpose Used

Digital Multimeter
(DMM)

Oscilloscope – Sensitivity: 1 mV

Differential Amplifier – Bandwid th > 20 MHz (bandwid th

RMS Volt Meter 20 Hz to 20 MHz R&S URE3 Measures RMS noise PV

50 Ω Feed-through
Termination

AC/DC Current
Converter

Electronic Load – Voltage range: 30 Vdc

AC Power Source Capable of supplying

8½ digits resolution Keysight 3458A Measures accurate DC

voltage

– Bandwidth limit: 20 MHz
–Probe:

– 1:1 with RF tip
– 10:1 with RF tip for > 50 V

limit : 20 MHz)
– AC coupling
– Amplifier x10

– Current range: 5 A
– Open and Short switches
– Transient On/Off

90 Vac to 250 Vac

Keysight DSO8064A or

Infiniium equivalent

LeCroy DA1855A Signal conditioning

Pomona Loads termination to

Tektronix TCP305 &

Tektronix TCPA300

Keysight 6060B Measures load and line

Keysight 6813B Functions as variable

Displays transient
response. Displays ripple
and noise waveform.

preamplifiers

match output impedance
of the differential amplifier

Converts current to
voltage

regulations and transient
response time

voltage transformer

PV

C

[a]

[b]

PV

PV

PV

PV

PV

58 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

Tab le 5-2 List of equipment (continued)

Equipment Requirement(s) Recommended model Purpose Used

Resistive Load (RL)–10 Ω/90 W (for U8001A)

–6 Ω/150 W (for U8002A)

Current Monitoring
Resistor (Shunt) (R

[a] PV = Performance Verification

[b] C = Calibration

–0.01 Ω ± 0.1%

)

– TCR less than 20 ppm/ºC

M

ISOTEK Co.

Model A-H

Measures ripple and noise PV

Current monitoring
resistor

Test consideration

For optimum performance, all procedures should comply with the following
recommendations:

– Assure that the calibration ambient temperature is stable and between 20 °C

and 30 °C. Ideally the calibration should be performed at 25 °C ±1 °C.

– Assure ambient relative humidity is less than 80%.

– Allow one hour warm up period by power on the power supply. During warm

up period, set the power supply to maximum programmable voltage and
current. Then, enable the output.

– Keep the test setup connection cables as short as possible.

PV

C

Keysight U8001A/U8002A User’s and Service Guide 59

5 Service Guide

Measurement techniques

Test setup

Most tests are performed at the front terminals as shown below. Measure the DC
voltage directly at the positive (+) and negative (–) terminals on the front panel.

Figure 5-2 Test setups

60 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

Current monitoring resistor

To eliminate output current measurement error caused by the voltage drops in the
leads and connections, connect the current monitoring resistor (R

(–) output terminal and the load as a four-terminal device. Connect the current
monitoring leads inside the load-lead connections directly at the monitoring
points on the resistor element.

) between the

M

General measurement techniques

To achieve best results when measuring load regulation, peak to peak voltage,
and transient response time of the power supply, measuring devices must be
connected through the hole in the neck of the binding post at (A) while the load
resistor is plugged into the front of the output terminals at (B). A measurement
made across the load includes the impedance of the leads to the load. The
impedance of the load leads can easily be several orders of the magnitude greater
than the power supply impedance and thus invalidate the measurement. To avoid
mutual coupling effects, each measuring device must be connected directly to the
output terminals by separate pairs of leads.

Figure 5-3 General measurement

Keysight U8001A/U8002A User’s and Service Guide 61

5 Service Guide

Electronic load

Many of the test procedures require the use of a variable load resistor capable of
dissipating the required power. Using a variable load resistor requires that
switches should be used to connect, disconnect, and short the load resistor. An
electronic load, if available, can be used in place of a variable load resistor and
switches. The electronic load is considerably easier to use than load resistors. It
eliminates the need for connecting resistors or rheostats in parallel to handle
power, it is much more stable than carbon-pile load, and it makes easy work of
switching between load conditions as is required for the load regulation and load
response tests. Substitution of the electronic load requires minor changes to the
test procedures in this chapter.

62 Keysight U8001A/U8002A User’s and Service Guide

Constant voltage (CV) verification

Voltage programming and readback accuracy

This test is to verify that the voltage programming and readback accuracy are
within published specifications.

Procedures:

1 Power off the power supply and connect a DMM between the (+) and (–)

terminals of the output to be tested. Remove the electronic load or resistor
block as shown in Figure 5-2(A), to operate as an open circuit.

2 Power on the power supply.

3 When the power supply is in limit mode, program the output voltage to 0 V

and the output current to the maximum programmable value.

4 Enable the output.

5 Wait for a few seconds for the output of the power supply to settle. Make sure

that the power supply is in CV mode.

6 Record the voltage reading on the DMM (V

the limit of 0 V ± 20 mV.

7 When the power supply is in meter mode, record the voltage reading displayed

on the front display of the power supply. This value should be within the limit

DMM

± 20 mV.

of V

8 Disable the output.

9 When the power supply is in limit mode, program the output voltage to full

rated value, i.e. 30 V.

Service Guide 5

). This value should be within

DMM

10 Enable the output.

11 Wait for a few seconds for the output of the power supply to settle. Make sure

that the power supply is in CV mode.

12 Record the voltage reading on the DMM (V

). This value should be within

DMM

the limit of 30 V ± 0.125 V.

13 When the power supply is in meter mode, record the voltage reading displayed

on the front display of the power supply. This value should be within the limit
of V

± 0.125 V.

DMM

Keysight U8001A/U8002A User’s and Service Guide 63

5 Service Guide

CV load effect (load regulation)

This test measures the change in the output voltage resulting from a change in
the output current from full load to no load or vice versa.

Procedures:

1 Power off the power supply and connect a DMM between the (+) and (–)

2 Power on the power supply.

3 When the power supply is in limit mode, program the output voltage to full

4 Enable the output.

5 Operate the electronic load in constant current mode and set its current to 3 A

6 Record the reading on the DMM.

7 Within a few seconds after step 6, operate the electronic load in open mode

8 Compare the reading obtained in steps 5 and 6. The difference should be

terminals of the output as shown in Figure 5-2(A).

rated value, i.e. 30 V and output current to the maximum programmable value.

for U8001A and 5 A for U8002A. Ensure that the power supply is in CV mode. If
not, adjust the electronic load so that the current drops slightly until the power
supply is in CV mode.

and record the reading on the DMM.

within the limit of 5 mV.

64 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

CV source effect (line regulation)

This test measures the change in output voltage that results from a change in AC
line voltage from the minimum value to maximum value.

Procedures:

1 Power-off the power supply and connect a DMM between the (+) and (–)

terminals of the output to be tested as shown in Figure 5-2(A).

2 Connect the AC power line through an AC voltage source. Adjust the AC

voltage source to provide nominal input voltage to the power supply.

3 Power on the power supply.

4 When the display is in the limit mode, program the output voltage to full rated

value, i.e. 30 V and output current to the maximum programmable value.

5 Enable the output.

6 Operate the electronic load in constant current mode and set its current to 3 A

for U8001A and 5 A for U8002A. Ensure that the power supply is in CV mode. If
not, adjust the electronic load so that the output current drops slightly until
the power supply is in CV mode.

7 Adjust the AC voltage source to low line voltage limit. Record the output

reading on the DMM.

8 Within a few seconds after step 7, adjust the AC voltage source to high line

voltage limit and record the voltage reading on the DMM.

9 The difference between the DMM readings in steps 7 and 8 should be within

the limit of 5 mV.

Line voltage

100 90 110

115 104 127

230 207 253

Low line voltage limit, V

ac

High line voltage limit, V

ac

Keysight U8001A/U8002A User’s and Service Guide 65

5 Service Guide

CV noise

CV noise is specified as the RMS or peak-to-peak output voltage in the frequency
range from 20 Hz to 20 MHz.

Procedures:

1 Power off the power supply and connect the output to be tested as shown in

2 Power on the power supply.

3 When the display is in the limit mode, program the output voltage to full rated

4 Enable the output of the power supply.

5 Make sure that the power supply is in CV mode. If not, adjust the resistive load

6 Configure the differential amplifier as follow:

Figure 5-2(C) to a differential amplifier and load resistor (10

Ω for U8002A)

6

Ω for U8001A and

value, i.e. 30 V and output current to the maximum programmable value.

so that the output current drops slightly until the power supply is in CV mode.

– Set to AC mode (positive and negative) to removes the DC component

– Set to differential mode

– Set gain to x10

– Set attenuation to 1

– Set low pass filter to 20 MHz bandwidth limit to filter out input signal which

contains higher frequency

– Set to zero precision voltage generator

– Set input impedance to 1 M

Ω

7 Configure the scope as follow:

– Set time range to 50 ms (20 Hz)

– Acquires every single sample at the maximum sampling rate and retains

only the min and max values in a “sampling region” (50 ms time range)

– Enable 20 MHz cut off frequency for better high frequency cut-off

– AC coupling

– Enable Auto-triggering

8 Allow the scope run for a few seconds to generate enough measurement

points.

66 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

9 Obtain the maximum peak-to-peak voltage measurement as indicated in the

scope. Divide this value by 10 to get the CV peak-to-peak noise measurement.
The result should not exceed 12 mV

pp

.

10 Configure the RMS voltmeter as below:

– Set high pass filter to 10 Hz

– AC coupling

11 Disconnect the oscilloscope and connect an RMS voltmeter in its place. Do

not disconnect the 50
by 10. The result should not exceed the RMS limits of 1 mV

Ω termination. Divide the reading of the RMS voltmeter

.

RMS

Keysight U8001A/U8002A User’s and Service Guide 67

5 Service Guide

Load transient response time

This test measures the time for the output voltage to recover to within 15 mV of
nominal output voltage following a load change from full load to half load or vice
versa.

Procedures:

1 Power off the power supply and connect the output to be tested as shown in

2 Power on the power supply.

3 When the display is in the limit mode, program the output voltage to full rated

4 Enable the output.

5 Set the electronic load to transient operation mode between one half of the

6 Set the oscilloscope coupling, internal sync and lock on either the positive or

7 Adjust the oscilloscope to display transients as shown in Figure 5-4. Note that

Figure 5-2(A) with an oscilloscope. Operate the electronic load in constant

current mode.

value, i.e. 30 V and output current to the maximum programmable value.

output's full rated value and the output’s full rated value at a 1 kHz rate with
50% duty cycle.

negative load transient.

the pulse width (t2–t1) of the transients at 15 mV from the base line is no more
than 50 µs for the output.

68 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

Figure 5-4 Graph of load transient response

Keysight U8001A/U8002A User’s and Service Guide 69

5 Service Guide

Constant Current (CC) Verification

Current programming and readback accuracy

This test is to verify that the current programming and readback accuracy are
within published specifications. The accuracy of the current monitoring resistor
must be 0.1% or better.

Procedures:

1 Power-off the power supply and connect a 0.01

resistor (R
monitoring resistor (R

2 Power on the power supply.

3 When the power supply is in limit mode, program the output voltage to

maximum programmable value and the current to 0 A.

4 Enable the output.

5 Wait for a few seconds for the output of the power supply to settle. Make sure

that the power supply is in CC mode.

6 Divide the voltage drop (DMM reading) across the current monitoring resistor

) by its resistance to convert to amps and record this value (IO). This value

(R

M

should be within the limit of 0 A ±20 mA.

7 When the power supply is in meter mode, record the current reading displayed

on the front display of the power supply. This value should be within the limit

±20 mA.

of I

O

8 Disable the output.

9 When the power supply is in limit mode, program the output current to full

rated value, i.e. 3 A for U8001A and 5 A for U8002A.

) across the output to be tested and a DMM across the current

M

).

M

Ω current shunt monitoring

10 Enable the output.

11 Wait for a few seconds for the output of the power supply to settle. Make sure

that the power supply is in CC mode.

70 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

12 Divide the voltage drop (DMM reading) across the current monitoring resistor

) by its resistance to convert to amps and record this value (IO). This value

(R

M

should be within the limit of:

– U8001A: 3 A ±30.5 mA

– U8002A: 5 A ±37.5 mA

13 When the power supply is in meter mode, record the current reading displayed

on the front display of the power supply. This value should be within the limit
of:

– U8001A: I

– U8002A: I

±30.5 mA

O

±37.5 mA

O

Keysight U8001A/U8002A User’s and Service Guide 71

5 Service Guide

CC load effect (load regulation)

This test measures the immediate change in output current resulting from a
change in the load from full rated output voltage to short circuit.

Procedures:

1 Power off the power supply and connect the output to be tested as shown in

2 Power on the power supply.

3 When the power supply is in limit mode, program the output voltage to

4 Enable the output.

5 Operate the electronic load in constant voltage mode and set its voltage to

6 Record the current reading by dividing the voltage reading on the DMM by the

Figure 5-2(B) with the DMM connected across the 0.01

resistor (R

).

M

Ω current monitoring

maximum programmable value and output current to full rated value, i.e. 3 A
for U8001A and 5A for U8002A.

30 V. Ensure that the power supply is in CC mode. If not, adjust the electronic
load so that the voltage drops slightly until the power supply is in CC mode.

resistance of the current monitoring resistor.

7 Within a few seconds after step 6, operate the electronic load in short mode

and record the current reading by dividing the voltage reading on the DMM by
the resistance of the current monitoring resistor.

8 Compare the reading obtained in steps 6 and 7. The difference should be

within the limit of:

– U8001A: 2.6 mA

– U8002A: 3 mA

72 Keysight U8001A/U8002A User’s and Service Guide

Service Guide 5

CC source effect (line regulation)

This test measures the change in output current that results from a change in AC
line voltage from the minimum value to the maximum value.

Procedures:

1 Power off the power supply and connect the output to be tested as shown in

Figure 5-2(B) with the DMM connected across the current monitoring resistor

).

(R

M

2 Connect the AC power line through an AC voltage source. Adjust the AC

voltage source to provide nominal input voltage to the power supply.

3 Power on the power supply.

4 When the display is in the limit mode, program the output voltage to maximum

programmable value and output current to full rated value, i.e. 3 A for U8001A
and 5 A for U8002A.

5 Enable the output.

6 Operate the electronic load in constant voltage mode and set its voltage to 30 V.

Ensure that the power supply is in CC mode. If not, adjust the electronic load so
that the output voltage drops slightly until the power supply is in CC mode.

7 Adjust the AC voltage source to low line voltage limit. Record the output

current reading by dividing the voltage reading on the DMM by the resistance
of the current monitoring resistor.

8 Within a few seconds after step 7, adjust the AC voltage source to high line

voltage limit and record the output current reading by dividing the voltage
reading on the DMM by the resistance of the current monitoring resistor.

9 Compare the reading obtained in steps 7 and 8. The difference should be

within the limit of:

– U8001A: 2.6 mA

– U8002A: 3 mA

Line voltage

100 90 110

115 104 127

230 207 253

Low line voltage limit, V

ac

High line voltage limit, V

ac

Keysight U8001A/U8002A User’s and Service Guide 73

5 Service Guide

CC noise

CC noise is specified as the RMS output current in a frequency range 20 Hz to
20 MHz with the power supply in constant current operation.

Procedures:

1 Power off the power supply and connect the output to be tested as shown in

2 Power on the power supply.

3 When the display is in the limit mode, program the output voltage to maximum

4 Enable the output.

5 Make sure that the power supply is in CC mode. If not, adjust the resistive load

6 Configure the differential amplifier as follow:

Figure 5-2(D) to an AC/DC converter and load resistor (10

Ω for U8002A).

6

Ω for U8001A and

programmable value and output current to full rated value, i.e. 3 A for U8001A
and 5 A for U8002A.

so that the output voltage drops slightly until the power supply is in CC mode.

– Set to AC mode (positive and negative) to removes the DC component

– Set to differential mode

– Set gain to x10

– Set attenuation to 1

– Set low pass filter to 20 MHz bandwidth limit to filter out input signal which

contains higher frequency

– Set to zero precision voltage generator

– Set input impedance to 1 M

Ω

7 Configure the RMS voltmeter as follow:

– Set high pass filter to10 Hz

– AC coupling

8 Divide the reading of the RMS voltmeter by 10 and then multiply the result by

5 to get the RMS noise measurement. The result should not exceed the RMS
limits of 3 mA

RMS

.

74 Keysight U8001A/U8002A User’s and Service Guide

Voltage Calibration

Before attempting to calibrate the power supply, please ensure that you have
disconnected all loads from the power supply and connect a digital voltmeter
(DVM) across the output terminals. You will be calibrating for low voltage, middle
voltage and high voltage point respectively. Make sure that the power supply is in
constant voltage (CV) mode along the voltage calibration.

1 Enter calibration mode.

– In order to enter the calibration mode, hold down the Memory button when

power on the power supply.

– The output is enabled.

– The calibration will start with voltage calibration mode.

– Display will show “C” blinking.

– The CV annunciator will be turned on.

– Ensure that the power supply is in CV mode. Otherwise, the CC annunciator

will fast-blink.

2 Low voltage calibration point.

– Display will show “C” blinking.

– The M1 annunciator will be turned on.

Service Guide 5

– Use the knob to enter the reading obtained from the DVM.

– Press the “Memory” button to save the changes and move to the next

calibration point. You will be able to perform this if the power supply is in
CV mode.

3 Middle voltage calibration point.

– Display will show “C” blinking.

– The M2 annunciator will be turned on.

– Use the knob to enter the reading obtained from the DVM.

– Press the “Memory” button to save the changes and move to the next

calibration point. You will be able to perform this if the power supply is in
CV mode.

Keysight U8001A/U8002A User’s and Service Guide 75

5 Service Guide

NOTE

4 High voltage calibration point.

5Voltage calibration

If you do not wish to continue with the current calibration, you may now turn off
the power supply to exit the calibration mode.

– Display will show “C” blinking.

– The M3 annunciator will be turned on.

– Use the knob to enter the reading obtained from the DVM.

– Press the “Memory” button to save the changes voltage calibration is done.

You will be able to perform this if the power supply is in CV mode.

– Display will show “donE” for a few seconds and the power supply will enter

the current calibration mode.

76 Keysight U8001A/U8002A User’s and Service Guide

Current Calibration

For current calibration, connect an appropriate shunt 0.01 Ω across the output
terminals, and connect a digital voltmeter (DVM) across the shunt resistor. Same
as voltage calibration, you will also be calibrating for low current, middle current
and high current calibration point respectively. Make sure that the power supply is
in constant current (CC) mode along the current calibration.

1 Current calibration mode

Service Guide 5

– Display will show “C” blinking.

– The CC annunciator will be turned on.

– Ensure that the power supply is in CC mode. Otherwise the CV annunciator

will fast-blink.

2 Low current calibration point.

– Display will show “C” blinking.

– The M1 annunciator will be turned on.

– Use the knob to enter the computed value (DVM reading divided by shunt

resistance).

– Press the “Memory” button to save the changes and move to the next

calibration point. You will be able to perform this if the power supply is in
CC mode.

Keysight U8001A/U8002A User’s and Service Guide 77

5 Service Guide

3 Middle current calibration point.

4 High current calibration point.

5Calibration done

– Display will show “C” blinking.

– The M2 annunciator will be turned on.

– Use the knob to enter the computed value (DVM reading divided by shunt

resistance).

– Press the “Memory” button to save the changes and move to the next

calibration point. You will be able to perform this if the power supply is in
CC mode.

– Display will show “C” blinking.

– The M3 annunciator will be turned on.

– Use the knob to enter the computed value (DVM reading divided by shunt

resistance).

– Press the “Memory” button to save the changes and the whole calibration

process is done. You will be able to perform this if the power supply is in CC
mode.

– Display will show “donE CAL”

– The output is disabled and the OFF annunciator will be turned on.

6 Reenter calibration mode

– Press the “Memory” button to reenter the calibration mode. The calibration

will start with voltage calibration mode.

7Exit calibration mode

– Turn off the power supply to exit the calibration mode.

8 Toggle between calibration modes

– Along the calibration process, you can toggle between voltage calibration

mode and current calibration mode by pressing the “Voltage/Current”
button.

78 Keysight U8001A/U8002A User’s and Service Guide

Keysight U8001A/U8002A Single Output DC Power Supplies
User’s and Service Guide

Appendix

Appendix A: List of Error Codes 80

79

Appendix

Appendix A: List of Error Codes

The following tables contain the list of error codes and the interpretations for each
code.

Operation errors

Codes Descriptions

101 Flash read/write failed

102 Invalid calibration data

111 Temperature too high

Calibration errors

Codes Descriptions

201 Flash read/write failed

211 Calibration failed for DAC CV

212 Calibration failed for DAC CC

213 Calibration failed for ADC CV

214 Calibration failed for ADC CC

215 Calibration failed for DAC OV

216 Calibration failed for DAC OC

80 Keysight U8001A/U8002A User’s and Service Guide

This information is subject to change
without notice. Always refer to the
Keysight website for the latest
revision.

© Keysight Technologies 2008-2017
Edition 8, September 2, 2017

Printed in Malaysia

*U8001-90001*