User's Guide
AC Power Solutions
HP Models 6811B, 6812B, and 6813B
For instruments with Serial Numbers:
HP 6811B: US38390101-up
HP 6812B: US38390101-up
HP 6813B: US38390101-up
HP Part No. 5962-0829 Printed in U.S.A.
Microfiche No 5962-0830 December, 1998
1
Warranty Information
CERTIFICATION
Hewlett-Packard Company certifies that this product met its published specifications at time of shipment from the
factory. Hewlett-Packard further certifies that its calibration measurements are traceable to the United States
National Bureau of Standards, to the extent allowed by the Bureau's calibration facility, and to the calibration facilities
of other International Standards Organization members.
WARRANTY
This Hewlett-Packard hardware product is warranted against defects in material and workmanship for a period of
three years from date of delivery. HP software and firmware products, which are designated by HP for use with a
hardware product and when properly installed on that hardware product, are warranted not to fail to execute their
programming instructions due to defects in material and workmanship for a period of 90 days from date of delivery.
During the warranty period Hewlett-Packard Company will, at its option, either repair or replace products which
prove to be defective. HP does not warrant that the operation for the software firmware, or hardware shall be
uninterrupted or error free.
For warranty service, with the exception of warranty options, this product must be returned to a service facility
designated by HP. Customer shall prepay shipping charges by (and shall pay all duty and taxes) for products
returned to HP for warranty service. Except for products returned to Customer from another country, HP shall pay
for return of products to Customer.
Warranty services outside the country of initial purchase are included in HP's product price, only if Customer pays
HP international prices (defined as destination local currency price, or U.S. or Geneva Export price).
If HP is unable, within a reasonable time to repair or replace any product to condition as warranted, the Customer
shall be entitled to a refund of the purchase price upon return of the product to HP.
LIMITATION OF WARRANTY
The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by the
Customer, Customer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the
environmental specifications for the product, or improper site preparation and maintenance. NO OTHER
WARRANTY IS EXPRESSED OR IMPLIED. HP SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
EXCLUSIVE REMEDIES
THE REMEDIES PROVIDED HEREIN ARE THE CUSTOMER'S SOLE AND EXCLUSIVE REMEDIES. HP SHALL
NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
WHETHER BASED ON CONTRACT, TORT, OR ANY OTHER LEGAL THEORY.
ASSISTANCE
The above statements apply only to the standard product warranty. Warranty options, extended support contacts,
product maintenance agreements and customer assistance agreements are also available. Contact your nearest
Hewlett-Packard Sales and Service office for further information on HP's full line of Support Programs.
2
Safety Summary
The following general safety precautions must be observed during all phases of operation of this instrument.
Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety
standards of design, manufacture, and intended use of the instrument. Hewlett-Packard Company assumes no
liability for the customer's failure to comply with these requirements.
WARNING: LETHAL VOLTAGES
Ac sources can supply 425 V peak at their output. DEATH on contact may result if the output terminals or
circuits connected to the output are touched when power is applied.
GENERAL
This product is a Safety Class 1 instrument (provided with a protective earth terminal). The protective features of
this product may be impaired if it is used in a manner not specified in the operation instructions.
Any LEDs used in this product are Class 1 LEDs as per IEC 825-1.
ENVIRONMENTAL CONDITONS
This instrument is intended for indoor use in an installation category II, pollution degree 2 environment. It is
designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the
specifications tables for the ac mains voltage requirements and ambient operating temperature range.
BEFORE APPLYING POWER
Verify that the product is set to match the available line voltage, the correct fuse is installed, and all safety
precautions are taken. Note the instrument's external markings described under "Safety Symbols".
GROUND THE INSTRUMENT
To minimize shock hazard, the instrument chassis and cover must be connected to an electrical ground. The
instrument must be connected to the ac power mains through a grounded power cable, with the ground wire
firmly connected to an electrical ground (safety ground) at the power outlet. Any interruption of the protective
(grounding) conductor or disconnection of the protective earth terminal will cause a potential shock hazard that
could result in personal injury.
ATTENTION: Un circuit de terre continu est essentiel en vue du fonctionnement sécuritaire de l'appareil.
Ne jamais mettre l'appareil en marche lorsque le conducteur de mise … la terre est d‚branch‚.
FUSES
Only fuses with the required rated current, voltage, and specified type (normal blow, time delay, etc.) should be
used. Do not use repaired fuses or short-circuited fuseholders. To do so could cause a shock or fire hazard.
DO NOT OPERATE IN AN EXPLOSIVE ATMOSPHERE
Do not operate the instrument in the presence of flammable gases or fumes.
DO NOT REMOVE THE INSTRUMENT COVER
Operating personnel must not remove instrument covers. Component replacement and internal adjustments must
be made only by qualified service personnel.
Instruments that appear damaged or defective should be made inoperative and secured against unintended
operation until they can be repaired by qualified service personnel.
3
SAFETY SYMBOLS
Direct current
Alternating current
Both direct and alternating current
Three-phase alternating current
Earth (ground) terminal
Protective earth (ground) terminal
Frame or chassis terminal
Terminal is at earth potential. Used for measurement and control circuits designed to be
operated with one terminal at earth potential.
Terminal for Neutral conductor on permanently installed equipment
WARNING
Caution
Terminal for Line conductor on permanently installed equipment
On (supply)
Off (supply)
Standby (supply). Units with this symbol are not completely disconnected from ac mains
when this switch is off. To completely disconnect the unit from ac mains, either disconnect
the power cord or have a qualified electrician install an external switch.
In position of a bi-stable push control
Out position of a bi-stable push control
Caution, risk of electric shock
Caution, hot surface
Caution (refer to accompanying documents)
The WARNING sign denotes a hazard. It calls attention to a procedure, practice, or the like,
which, if not correctly performed or adhered to, could result in personal injury. Do not
proceed beyond a WARNING sign until the indicated conditions are fully understood and
met.
The CAUTION sign denotes a hazard. It calls attention to an operating procedure, or the like,
which, if not correctly performed or adhered to, could result in damage to or destruction of
part or all of the product. Do not proceed beyond a CAUTION sign until the indicated
conditions are fully understood and met.
4
Declaration Page
Manufacturer's Name: Hewlett-Packard Company
Manufacturer's Address: 150 Green Pond Road
declares that the Product
Product Name: a) AC Power Source/Analyzer
Model Number(s): a) HP 6811B, 6813B, 6812B, 6811A, 6812A, 6813A
DECLARATION OF CONFORMITY
according to ISO/IEC Guide 22 and EN 45014
Rockaway, New Jersey 07866
U.S.A.
b) Harmonic/Flicker Test System
b) HP 6841A, 6842A
conforms to the following Product Specifications:
Safety: IEC 1010-1:1990+A1(1992) / EN 61010-1:1993
EMC: CISPR 11:1990 / EN 55011:1991 - Group 1 Class A
IEC 801-2:1991 / EN 50082-1:1992 - 4 kV CD, 8 kV AD
IEC 801-3:1984 / EN 50082-1:1992 - 3 V / m
IEC 801-4:1988 / EN 50082-1:1992 - 0.5 kV Signal Lines
1 kV Power Lines
Supplementary Information:
The product herewith complies with the requirements of the Low Voltage Directive
73/23/EEC and the EMC Directive 89/336/EEC and carries the CE-marking accordingly.
New Jersey January 1997 __ __
Location Date Bruce Krueger / Quality Manager
European Contact: Your local Hewlett-Packard Sales and Service Office or Hewlett-Packard GmbH,
Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)
5
Acoustic Noise Information
Herstellerbescheinigung
Diese Information steht im Zusammenhang mit den Anforderungen der
Maschinenläminformationsverordnung vom 18 Januar 1991.
* Schalldruckpegel Lp <70 dB(A)
* Am Arbeitsplatz
* Normaler Betrieb
* Nach EN 27779 (Typprüfung).
Manufacturer's Declaration
This statement is provided to comply with the requirements of the German Sound Emission Directive,
from 18 January 1991.
* Sound Pressure Lp <70 dB(A)
* At Operator Position
* Normal Operation
* According to EN 27779 (Type Test).
Printing History
The edition and current revision of this manual are indicated below. Reprints of this manual containing
minor corrections and updates may have the same printing date. Revised editions are identified by a new
printing date. A revised edition incorporates all new or corrected material since the previous printing date.
Changes to the manual occurring between revisions are covered by change sheets shipped with the manual.
In some cases, the manual change applies only to specific instruments. Instructions provided on the change
sheet will indicate if a particular change applies only to certain instruments.
This document contains proprietary information protected by copyright. All rights are reserved. No part of
this document may be photocopied, reproduced, or translated into another language without the prior
consent of Hewlett-Packard Company. The information contained in this document is subject to change
without notice.
Copyright 1995, 1997, 1998 Hewlett-Packard Company Edition 1 _________August, 1995
Edition 2 _________February, 1997
Edition 3 _________March, 1998
Edition 4 _________December 1998
6
Table of Contents
Warranty Information 2
Safety Summary 3
Declaration of Conformity 5
Acoustic Noise Information 6
Printing History 6
Table of Contents 7
1 GENERAL INFORMATION 11
Document Orientation 11
Earlier AC Source Models 12
Safety Considerations 12
Options and Parts 12
Description 13
Capabilities 14
Front Panel/Remote Operation 14
Steady-state Output Characteristic 15
Peak Current/Dynamic Power Capability 16
Peak Current Limit 16
Peak Inrush Example 16
RMS Current Limit Circuit 18
Voltage Regulation 18
Real Time Regulation 18
RMS Regulation 18
Output Impedance 18
Output Coupling 19
2 INSTALLATION 21
Inspection 21
Damage 21
Packaging Material 21
Items Supplied 21
Cleaning 21
Location 22
Bench Operation 22
Rack Mounting 22
Input Connections 23
Input Source and Line Fuse 23
Installing the Power Cord 23
Output Connections 24
Wire Considerations 25
Voltage Drops 25
Remote Sense Connections 25
Remote Sensing and OVP Considerations 27
Trigger Connections 27
Digital Connections 27
Controller Connections 28
HP-IB Connector 28
RS-232 Interface 29
7
3 TURN-ON CHECKOUT 31
Introduction 31
Preliminary Checkout 31
Using the Keypad 32
Checkout Procedure 32
In Case of Trouble 34
Error Messages 34
Line Fuse 35
4 FRONT PANEL OPERATION 37
Introduction 37
Front Panel Description 37
System Keys 39
Function Keys 40
Immediate Action Keys 40
Scrolling Keys 40
Meter Display Keys 41
Output Control Keys 42
Protection and Status Control Keys 44
Trigger and List Control Keys 45
Entry Keys 46
Examples of Front Panel Programming 47
1 - Setting the Output Voltage Amplitude 47
2 - Setting the Output Frequency 48
3 - Setting the DC Offset 48
4 - Setting a Protection Feature 49
5 - Clearing Protection Conditions 49
6 - Using Transient Voltage Modes 50
7 - Trigger Delays and Phase Synchronization 53
8 - Using Slew Rates to Generate Waveforms 55
9 - Measuring Peak Inrush Current 57
10 - Setting the HP-IB Address and RS-232 Parameters 58
11 - Saving and Recalling Operating States 58
A SPECIFICATIONS 59
Specifications 59
Supplemental Characteristics 61
Operation Below 45 Hz 63
B VERIFICATION AND CALIBRATION 65
Introduction 65
Equipment Required 65
Test Setup 66
Performing the Verification Tests 67
Turn-On Checkout Procedure 67
AC Voltage Programming and Measurement Accuracy 67
DC Voltage Programming and Measurement Accuracy 68
RMS Current Accuracy Test 68
Performing the Calibration Procedure 71
Front Panel Calibration Menu 71
8
Front Panel Calibration 72
Enable Calibration Mode 72
Calibrating and Entering Voltage Offset Values 72
Calibrating and Entering DC Voltage Gain Values 73
Calibrating and Entering AC rms Voltage Gain Values 73
Calibrating the OVP Trip Point 74
Calibrating and Entering rms Current Values 74
Calibrating and Entering rms Current Measurement Values 75
Calibrating the Output Impedance 75
Saving the Calibration Constants 75
Changing the Calibration Password 76
Calibration Error Messages 76
Calibration Over the HP-IB 76
HP Calibration Program Listing 76
C ERROR MESSAGES 81
Error Number List 81
D LINE VOLTAGE CONVERSION 85
Open the Unit 85
Check the Jumper Wire (Model HP 6811B/6812B only) 85
Check the Line Jumpers (all Models) 85
Check the Power Transformer Connector (all Models) 85
Close the Unit 86
INDEX 87
9
1
General Information
Document Orientation
This manual describes the operation of the HP 6811B/6812B/6813B AC Power Solutions. These units will
be referred to as "ac sources" throughout this manual. The following documents are shipped with your ac
source:
♦ a Quick-Start Guide, to help you quickly get started using the ac source
♦ a User's Guide, containing detailed installation, checkout, and front panel information
♦ a Programming Guide, containing detailed HP-IB programming information
♦ a Quick Reference Card, designed as a memory jogger for the experienced user
You will find information on the following tasks in these guides. Refer to the table of contents of each guide
for a complete list of the topics.
Topic Location
Accessories and Options Chapter 1 - this guide
Calibrating the ac source Appendix B - this guide
Front panel keys Chapter 4 - this guide
Front panel programming examples Chapter 4 - this guide
Line voltage connections Chapter 2 - this guide
Line voltage ratings Appendix A - this guide
Line voltage conversion Appendix D - this guide
Operator replaceable parts Chapter 1 - this guide
Operator troubleshooting Chapter 3 - this guide
Operating characteristics Appendix A - this guide
Performance specifications Appendix A - this guide
Quick operating checkout Chapter 3 - this guide
Rack mounting Chapter 2 - this guide
RS-232 operation Chapter 2 - this guide
SCPI programming examples Chapter 3 - Programming Guide
SCPI programming commands Chapter 4 - Programming Guide
Turn-on/checkout Chapter 3 - this guide
Wiring - discrete fault indicator (DFI) Chapter 2 - this guide
- HP-IB controller Chapter 2 - this guide
- load or loads Chapter 2 - this guide
- voltage sensing (local and remote) Chapter 2 - this guide
- remote inhibit (RI) Chapter 2 - this guide
11
1 - General Information
Earlier AC Source Models
With the exception of some minor readback specification differences, information in this manual also
applies to the following earlier ac source models:
Information about this
current model
HP 6811B HP 6811A AC Power Source/Analyzer
HP 6812B HP 6812A AC Power Source/Analyzer
HP 6813B HP 6813A AC Power Source/Analyzer
also applies to the following earlier models:
HP 6841A Harmonic/Flicker Test System in
normal mode
HP 6842A Harmonic/Flicker Test System in
normal mode
Safety Considerations
This ac source is a Safety Class 1 instrument, which means it has a protective earth terminal. That terminal
must be connected to earth ground through a power source equipped with a ground receptacle. Refer to the
Safety Summary page at the beginning of this guide for general safety information. Before installation or
operation, check the ac source and review this guide for safety warnings and instructions. Safety warnings
for specific procedures are located at appropriate places in the guide.
Options and Parts
Table 1-1. Options
Option Model Description
0BN All Extra documentation
1CM All Rack mount kit (HP p/n 5062-3977)
1CP All Rack mount kit with handles (HP p/n 5062-3983)
100 HP 6811B/6812B 87-106 Vac, 48-63 Hz (Japan only)
200 HP 6813B 174-106 Vac, 48-63 Hz (Japan only)
230 HP 6811B/6812B 191-254 Vac, 48-63 Hz
831 HP 6812B/6813B 12 AWG, 200 to 240 Vac, unterminated
832 HP 6813B 4-mm2 wire size, unterminated
833 HP 6812B 1.5-mm2 wire size, 200 to 240 Vac, unterminated
834 HP 6812B 10 AWG, 100 to 120 Vac, unterminated
841 HP 6812B/6813B Line cord with NEMA 6-20P; 20A, 250 V plug
842 HP 6813B Line cord with IEC 309; 32A, 220 V plug
844 HP 6813B Line cord with NEMA 6-30P; 30A, 250 V locking plug
845 HP 6812B Line cord with IEC 309; 16 A, 220 V plug
846 HP 6812B Line cord with NEMA L5-30P; 30 A, 120 V plug
847 HP 6812B Line cord with CEE 7/7; 16 A, 220 V plug
848 HP 6812B Line cord with BS 546; 15 A, 240 V plug
Support rails (HP p/n 1494-0059) are required when rack mounting units with options 1CM and 1CP.
HP 6811B units are shipped with the correct line cord for the destination country.
12
The following table lists some common user-replaceable parts:
Table 1-2. Operator Replaceable Parts
Item HP Part Number
Power cord assembly see "Options"
Rack mount kit see "Options"
4-terminal digital connector plug 1252-1488
Ac input safety cover (with strain relief and bushing) 5040-1676
Screw (3), ac input barrier block (6-32 x 5/16in) N/A
Ac output safety cover 5040-1704
Line fuse for HP 6812B (30 A) 2110-0910
Line fuse for HP 6813B (25 A) 2110-0849
Line fuse for HP 6811B (20 A) 2110-0098
Screw (2), ac output safety cover (m4 x 0.7in) 0515-0053
Screw (5), ac output barrier block (6-32 x 5/16 in) N/A
User's Guide (this manual) 5962-0829
Programming Guide 5962-0889
Quick Start Guide 5962-0883
Quick Reference Card 5962-0885
General Information - 1
Description
The ac source combines three instruments in one unit as shown in the following figure. The function
generator produces waveforms with programmable amplitude, frequency, and shape. The power amplifier
amplifies the function generator signal to produce the ac power for your application. The measurement
functions range from a simple readback of rms voltage and current, to sophisticated capabilities such as
waveform analysis.
DAC
WAVEFORM
GENERATOR
SOURCE
BIPOLAR
AMPLIFIER
shunt
MEASUREMENT
BLOCK
POWERMETER
FFT ANALYZER
Figure 1-1. AC Source Functional Elements
13
1 - General Information
The following model ac power sources are described in this User's Guide:
Model Description
HP 6811B 0-300 V rms; 375 VA (425 V peak; 40 A peak)
HP 6812B 0-300 V rms; 750 VA (425 V peak; 40 A peak)
HP 6813B 0-300 V rms; 1750 VA (425 V peak; 80 A peak)
Capabilities
♦ Programmable ac voltage, dc voltage, frequency, phase, and current limit.
♦ Sine, square, clipped sine, and user-definable waveforms.
♦ Programmable output impedance.
♦ Voltage and frequency slew control.
♦ Synthesized waveform generation for high resolution and accuracy in frequency, low waveform
distortion, and glitch-free phase transitions.
♦ Step and pulse output transients for generating surge, sag, dropout, and other line disturbance
simulations.
♦ Nonvolatile list programming for generating complex output transients or test sequences.
♦ Nonvolatile state and waveform storage and recall.
♦ Extensive measurement capability:
Ac rms, dc, ac+dc voltage and current and peak current.
Real, reactive, and apparent power.
Harmonic analysis of voltage and current waveforms gives amplitude, phase, and total
harmonic distortion results up to the 50th harmonic.
Triggered acquisition of digitized voltage and current with extensive post-acquisition
calculations.
All measurements made with 16-bit resolution.
♦ Trigger In and Trigger Out for synchronizing transient events or measurements with external
signals.
♦ Front panel control with 14-character vacuum flourescent display, keypad, and rotary pulse
generators for voltage and frequency settings.
♦ Built-in HP-IB and RS-232 interface programming with SCPI command language.
♦ Over-voltage, over-power, over-current, over-temperature, and RI/DFI protection features.
♦ Built-in output and sense disconnect relays.
♦ Output terminals floating with respect to chassis ground.
♦ Extensive selftest, status reporting, and software calibration.
Front Panel/Remote Operation
The front panel has both rotary (RPG) and keypad controls for setting the output voltage and frequency.
The panel display provides digital readouts of a number of output measurements. Annunciators display the
operating status of the ac source. System keys let you perform system functions such as setting the HP-IB
address and recalling operating states. Front panel Function keys access the ac source function menus.
Front panel Entry keys let you select and enter parameter values. Refer to chapter 4 for a complete
description of the front panel controls.
Remotely programming is accomplished from either the HP-IB bus or from an RS-232 serial port. HP-IB
and RS-232 programming uses SCPI commands (Standard Commands for Programmable Instruments) that
make the ac source programs compatible with those of other instruments. AC source status registers permit
remote monitoring of a wide variety of ac source operating conditions
14
General Information - 1
Vdc
NOTE: Refer to the ac source Programming Guide for further information about remotely
programming the ac source.
Steady-state Output Characteristic
The ac source's steady-state output characteristic is shown in the following figure. Steady-state
characteristics are defined as those output ratings that will be maintained by the ac source for an indefinite
time. (The section "Peak Current Capability" describes the dynamic output capability of the unit.) The
figure shows both the ac and the dc characteristics. With programmable output coupling, the ac source can
supply dc as well as ac output voltages.
Ac source operation is specified from 45 to 1000 Hz (see Appendix A). However, you can operate the unit
at frequencies less that 45 Hz. The operating characteristics of the ac source at autput frequencies below 45
Hz are documented in Table A-3 of Appendix A.
300 V
115V (6811B/6812B)
135V (6813B)
424 V
Vrms
0
1.25A (6811B)
2.5A (6812B)
5.8A (6813B)
375VA (6811B)
750VA (6812B)
1750VA (6813B)
3.25A (6811B)
6.5A (6812B)
13A (6813B)
Irms
-Idc
-2.5A (6811B)
-5A (6812B)
-10A (6813B)
115V (6811B/6812B)
135V (6813B)
0
-Vdc
AC CHARACTERISTIC
DC CHARACTERISTIC
(45Hz - 1kHz sinewave)
Figure 1-2. Steady-state Output Characteristic (in real-time mode)
285W (6811B)
575W (6812B)
1350W (6813B)
0.67A (6811B) 2.5A (6811B)
1.35A (6812B)
3.17A (6813B)
-424 V
5A (6812B)
10A (6813B)
Idc
15
1 - General Information
Peak Current/Dynamic Power Capability
The ac source can generate peak currents that exceed the rms current capability of the unit. This not only
applies when operating in ac mode, but also when programming output pulses in dc mode. Although the
unit will generate peak output currents up to 40A (HP 6811B/6812B) or 80A (HP 6813B), the unit can
only maintain this output for a limited time. If the output of the unit exceeds the limit of the safe operating
area (SOA), the unit will activate its internal protection mode and turn its output off. This SOA limit is
based on output voltage, output current, output duration, and heatsink temperature.
NOTE: Refer to chapter 4 on how to clear the unit when the internal protection mode has been
activated.
Peak Current Limit
By programming the peak current limit, you can prevent the unit from exceeding the safe operating area,
activating its internal protection mode, and turning the output off. The peak current limit circuit limits the
instantaneous output current. It functions by reducing the instantaneous output voltage to keep the output
peak current within the programmed limit. Because the circuit acts instantly, the effect is that it will clip the
peaks of the output voltage waveform. Additionally, with fast and/or large voltage transitions, the unit may
momentarily go into CC operating mode due to current in the output capacitor. This serves to limit the rate
of change of output voltage.
The following table gives approximate indications of how long the unit will tolerate peak output currents
before the SOA limits are exceeded. Because these values are voltage dependent, the table includes various
equivalent dc voltages along with the peak current values. The voltages shown in the table are NOT the
programmed voltages, but the average voltage values that will appear at the output when the indicated high
current condition exists. The SOA circuit becomes active at higher voltage and current values as well as at
longer duration times.
Table 1-3. Typical Peak Current Output Capacities
HP 6813B HP 6811B equivalent dc voltage when current is flowing
1
HP 6812B 25 75 125 190 250 360
20 A 10 A >100 ms >100 ms >100 ms >100 ms >100 ms >100 ms
30 A 15 A >100 ms 100 ms 30 ms 24 ms 19 ms 15 ms
40 A 20 A 12 ms 9.2 ms 8.4 ms 7.6 ms 6.8 ms 5.9 ms
50 A 25 A 5.6 ms 5.1 ms 4.7 ms 4.4 ms 4 ms 3.5 ms
60 A 30 A 3.7 ms 3.4 ms 3.1 ms 2.9 ms 2.6 ms 2.3 ms
70 A 35 A 2.6 ms 2.4 ms 2.2 ms 2.1 ms 1.9 ms 1.7 ms
80 A 40 A 2 ms 1.8 ms 1.7 ms 1.6 ms 1.4 ms 1.3 ms
1
Based on 25C ambient temperature, with heatsink temperature less than 50C.
Peak Inrush Example
The following table gives the recommended initial I
254 Vac 60 Hz sine wave, as a function of load capacitance. The load on the output is a full-wave bridge
along with the indicated capacitor. The load resistance across the capacitor is infinite. The recommended
I
will change as a function of changes in input as follows:
peak
settings when the ac source output is a 127 Vac or
peak
16
General Information - 1
♦ as voltage increases, the I
♦ as frequency increases, the I
♦ as load resistance decreases, the I
Note that the purpose of programming the I
setting needs to be decreased.
peak
setting can be increased.
peak
setting needs to be decreased.
peak
current is to prevent the unit from activating its internal
peak
protection mode as a result of exceeding the SOA limits, and turning the output off. These initial settings
may have to be reduced if the SOA circuit trips when the output is turned on. Sometimes trial and error
must be used to arrive at the proper values of I
Table 1-4. Recommended I
peak
Capacitance in µF
.
peak
Settings as a Function of Loop Capacitance
I
setting
peak
127 V 254 V
≤ 1100
500 80 A
1200 - 60 A
1700 700 50 A
5000 1000 45 A
> 5000 > 1000 < 45 A
The following waveform illustrates the inrush current capability of the ac source. The peak current is
limited during inrush in accord with table 1-3 to keep the ac source from turning its output off. Note that
the output current waveform returns to its normal shape when the current drops below the peak current
limit setting.
I PEAK=45A
VOLTAGE IS
UNDISTORTED
(115 Vrms)
CURRENT
WAVEFORM
VOLTAGE
WAVEFORM
PEAK CURRENT
< 45 A
0
Figure 1-3. Peak Inrush Current Example
17
1 - General Information
RMS Current Limit Circuit
The output rms current limit is adjustable to any value within the range of the unit. If the load attempts to
draw more current than the programmed limit, the output voltage is reduced to keep the rms current within
the limit. When the output voltage is reduced, the waveform shape is preserved. In other words, all parts of
the voltage cycle are reduced -- not just the peaks.
NOTE: The speed at which the rms current circuit operates depends on the output voltage setting
and the load impedance. The circuit responds more slowly at low output voltages and at
high output impedances. With constant power or negative resistance loads, the rms current
limit circuit causes the output voltage to go to zero.
Voltage Regulation
Real Time Regulation
The default method of output regulation used by the ac source is real-time voltage regulation. Real-time
voltage regulation tries to provide the actual programmed waveform at the output of the ac source. It offers
the best overall programming response and fastest settling times. It does not have any limitations for
waveforms and transients with frequency content below 45 Hz.
RMS Regulation
Rms voltage regulation assists real-time regulation to level out or stabilize the rms value of the ac
component of the output voltage. Use rms voltage regulation in the following situations:
♦ If you experience load regulation effects with heavy loads.
♦ If you experience frequency regulation problems with heavy loads and you require flatter
programming accuracy at higher frequencies.
♦ In conjunction with programmable output impedance, if you wish to maintain the rms level of
output voltage as the source impedance is increases. (Refer to Output Impedance for more
information.)
The command to specify voltage regulation is VOLT:ALC:DET RTIM | RMS.
NOTE: Do not use rms voltage regulation when operating at frequencies less than 45 Hz.
Output Impedance
You can program the real and/or reactive (resistive and/or inductive) part of the output impedance of the ac
source. Inductive output impedances can be programmed in the range of 20 to 1000 microhenries. Resistive
load impedances can be programmed in the range of 0 to 1 ohms.
When programming output impedances, the lower your load impedance, the LESS programmed impedance
you can use and still maintain output voltage stability. This applies particularly for load impedances less
than 1 ohm.
18
General Information - 1
CAUTION: Programming the ac source output impedance into a load with a low impedance can
cause output voltage instability, which may damage the ac source. Stability MUST be
maintained when operating the ac source with programmable resistance or
inductance.
To check for stability, monitor the output voltage with an oscilloscope. Instability exists if
a 5kHz to 20kHz oscillation, which is dependent upon the ac source's programmed
inductance and the capacitance of the load, is present at any time during the following
procedure.
1. When programming inductance, it is recommended that you first add a series
resistance either by programming the output resistance to 1 ohm or by adding an
equivalent external resistor.
2. Slowly program the inductance to the desired level while monitoring the output for
any voltage instability. Do not proceed any further if the output shows any signs of
instability.
3. If less output resistance is required, slowly start lowering the resistance while
monitoring the output for any voltage instability. Do not proceed any further if the
output shows any signs of instability.
If you cannot achieve satisfactory results with this procedure, disable the output
impedance control and use an external impedance network.
Rms voltage regulation can be used in conjunction with programmable output impedance to regulate the
rms value of the ac component of the output voltage when programmed impedances cause distortion with
nonlinear loads or reduced output voltage due to regulation effects.
Note that real-time voltage regulation will permit the load current to cause output voltage degradation
based on the programmed impedance and current drawn from the source, whereas rms regulation will
reestablish the rms value at the programmed level.
Output Coupling
Ac output coupling mode mimics a transformer-coupled output, working to maintain zero average output
voltage. This means that the output tries to remove any dc content on the output, whether the dc content is
generated from a programmed offset or results from transients with dc content. The ac output coupling has
a corner frequency of about 2 Hz, which will not prevent transient waveforms that may have short-term dc
content, but will regulate the waveform back to an average value of zero volts in the steady state.
Dc output coupling mode is used to generate dc offset voltages or output transients that have net dc
components. In either mode of operation, the maximum voltage that the ac source can output is limited to
425 V peak.
The ac capability of the output is limited by VA (volt-amperes) rather than power (watts). The amount of
VA available to a load can be determined by examining figure 1-2. Full output VA is available with no
limitations except for the boundaries imposed by the maximum rms voltage of 300V, and the maximum
rms current, which is model-dependent. Note that large peak power transients can be delivered by the ac
source as earlier described under "Peak Current Capability"(Appendix A documents the ac source's
specifications and supplemental characteristics.)
19
2
Installation
Inspection
Damage
When you receive your ac source, inspect it for any obvious damage that may have occurred during
shipment. If there is damage, notify the shipping carrier and the nearest HP Sales and Support Office
immediately. The list of HP Sales and Support Offices is at the back of this guide. Warranty information
is printed in the front of this guide.
Packaging Material
Until you have checked out the ac source, save the shipping carton and packing materials in case the unit
has to be returned. If you return the ac source for service, attach a tag identifying the model number and the
owner. Also include a brief description of the problem.
Items Supplied
Check that the following items are included with your ac source. Some items are installed in the unit.
Power Cord
Digital connector
Safety covers
Manuals
Change page
A power cord appropriate for your location. The cord may or may not be
terminated in a power plug (see "Options" in chapter 1). If the cord is not
included, contact your nearest HP Sales and Support Office (refer to the list at
the back of this guide).
4-terminal digital plug that connects to the back of the unit.
Ac input cover with strain relief
Ac output cover
User’s Guide
Programming Guide
Quick Start Guide
Quick Reference Card
If applicable, change sheets may be included with this guide. If there are change
sheets, make the indicated corrections in this guide.
Cleaning
Use a dry cloth or one slightly dampened with water to clean the external case parts. Do not attempt to
clean internally.
WARNING: To prevent electric shock, unplug the unit before cleaning.
21
2 - Installation
Location
Refer to the Safety Summary page at the beginning of this manual for safety-related information about
environmental conditions.
CAUTION: HP 6811B/6812B units weigh 28.2 kg (62 lbs).
HP 6813B units weigh 32.7 kg (72 lbs).
Obtain adequate help when moving or mounting the unit in the rack.
Bench Operation
The outline diagram in figure 2-1 gives the dimensions of your ac source. The feet may be removed for
rack mounting. Your ac source must be installed in a location that allows sufficient space at the sides and
back of the unit for adequate air circulation. Minimum clearances are 1 inch (25 mm) along the sides. Do
not block the fan exhaust at the rear of the unit.
Rack Mounting
The ac source can be mounted in a standard 19-inch rack panel or cabinet. Rack mounting kits are
available as Option 1CM or 1CP. Installation instructions are included with each rack mounting kit. HP ac
sources also require instrument support rails in addition to the rack mount kit. Support rails are
normally ordered with the cabinet and are not included with the rack mounting kits.
12.7mm
0.5"
REAR
128mm
5.04"
50.8mm
2.0"
TOP
574.7mm
22.6"
SIDE
425.5mm
16.75"
132.6mm
5.25"
22
Figure 2-1. Outline Diagram
Installation - 2
(HP 6811A)
(HP 6811A)
(HP 6811A)
(HP 6811A)
Input Connections
Input Source and Line Fuse
You can operate your ac source from a single-phase ac power source as indicated on the rear panel Line
Rating label. See "ac Input Voltage Range" in Table A-2 of Appendix A for details.
NOTE: The power ac source must be on a dedicated line with no other devices consuming current
from it.
The line fuse is located inside the ac source. Refer to "In case of Trouble" in Chapter 3 for instructions on
fuse replacement.
Installing the Power Cord
The power cord supplied with the ac source may or may not include a power plug at one end of the cord.
Figure 2-2 shows the various power plugs. Terminating connections are attached to the other end of the
cord.
Option 841
8120-8605
(HP 6811A)
Option 842
8120-8106
Option 831,832,833,834
Option 844
8120-8607
8120-8609
#8 Ring Terminals
Option 846Option 845
8120-8610
(HP 6811A)
Option 847
8120-8608
(HP 6811A)
Option 848
8120-8611
Figure 2-2. Power Cord Plug Configurations
WARNING: Installation of the power cord must be done by a qualified and licensed electrician and
must be in accordance with local electrical codes.
See Figure 2-3 while performing the following procedure.
a. If they are not already in place, position the strain relief connector (9), safety cover (5), rubber
boot (8) and connector nut (7) on the power cord (6).
b. Secure the ground wire (2) to the chassis earth ground stud.
c. Connect the neutral wire (1) to the N power input terminal.
d. Connect the line (3) to the L1 power input terminal.
e. Position the safety cover over the power input terminals and tighten the cover and strain relief
connector screws.
23
2 - Installation
L1 L2(N)
1
2
3
4
5
6
7
1. GROUND CONNECTION (GRN/YEL OR GRN)
2. LINE CONNECTION (BROWN OR BLACK)
3. NEUTRAL CONNECTION (BLUE OR WHITE)
4. POWER CORD
8
5. CONNECTOR NUT
6. RUBBER BOOT
7. POWER SAFETY COVER
8. STRAIN RELIEF CONNECTOR
Figure 2-3. Connecting the Power Cord
Output Connections
The power output terminal block has a floating output terminal connection and a floating neutral line for
the return connection. A separate earth ground terminal is located on the extreme right of the terminal
block.
!
SENSE
01 01 COM COM
24
300 VAC MAX TO
01 PHASE 1 OUTPUT CONNECTION
COM PHASE RETURN CONNECTION
GROUND CONNECTION
Figure 2-4. Output Connections
Installation - 2
Wire Considerations
NOTE: To minimize the possibility of instability on the output, keep load leads as short as possible
bundle or twist the leads tightly together to minimize inductance
Current Ratings
Fire Hazard To satisfy safety requirements, load wires must be large enough not to overheat when
carrying the maximum short-circuit current of the ac source. If there is more than one
load, then any pair of load wires must be capable of safely carrying the full-rated
current of the ac source.
Table 2-1 lists the characteristics of AWG (American Wire Gage) copper wire.
Table 2-1. Ampacity and Resistance of Stranded Copper Conductors
AWG No. Ampacity
14 25 0.0103 6 80 0.0016
12 30 0.0065 4 105 0.0010
10 40 0.0041 2 140 0.00064
8 60 0.0025 1/0 195 0.00040
1. Ampacity is based on 30°C ambient temperature with conductor rated at 60°C. For ambient
temperature other than 30°C, multiply the above ampacities by the following constants:
Temp. (°C)
21-25 1.08 41-45 0.71
26-30 1.00 46-50 0.58
31-35 0.91 51-55 0.41
36-40 0.82
2. Resistance is nominal at 75 °C wire temperature.
1
Resistance
(Ω/m)
Constant
2
NOTES:
AWG No. Ampacity
Temp. (°C) Temp. (°C)
1
Resistance
(Ω/m)
2
Voltage Drops
The load wires must also 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. Refer to Table 2-1 to calculate the voltage drop
for some commonly used AWG copper wire. If load regulation becomes a problem refer to the section
"Remote Sense Connections".
Remote Sense Connections
Under normal operation, the ac source senses the output voltage at the output terminals on the back of the
unit. External sense terminals are available on the back of the unit that allow the output voltages to be
sensed at the load, compensating for impedance losses in the load wiring. As shown in the following figure:
25
2 - Installation
♦ Connect the phase 1 (1) sense terminals to the side of the load that connects to the corresponding
output terminal.
♦ Connect the Neutral (COM) sense terminal connector to the neutral side of the load.
♦ Twist and shield all signal wires to and from the sense connectors.
The sense leads are part of the ac source's feedback path and must be kept at a low resistance in order to
maintain optimal performance. Connect the sense leads carefully so that they do not become open-circuited.
CAUTION: If the sense leads are left unconnected or become open during operation, the ac source will
regulate at the output terminals, but with a 40% increase in output voltage over the
programmed limit. The meter circuit cannot read back this increase in output voltage when
the sense lead is disconnected.
Set the ALC command to EXT (external) to enable remote sensing. The ALC command is located under
the Voltage key as explained in chapter 4. Set the ALC command to INT (internal) to disable remote
sensing.
NOTE: If you are using external relays to connect and disconnect the load and sense connections,
do NOT permit the sense connections to open when remote sensing is enabled. First disable
remote sensing, then open the sense and load connections.
!
SENSE
01
Figure 2-5. Remote Sense Connections
01
LOAD
COM COM
26
Installation - 2
Remote Sensing and OVP Considerations
In remote sense applications, the voltage drop in the load leads subtracts from the available load voltage
(see "Remote Sensing Capability" in appendix A). As the ac source increases its output to overcome this
voltage drop, the sum of the programmed voltage and the load-lead drop may exceed the ac source's
maximum voltage rating. This may trip the OV protection circuit, which senses the voltage at the output
terminals, not at the load. When using remote sensing, you must program the OVP trip voltage high enough
to compensate for the voltage drop between the output terminals and the load.
NOTE: If the load causes the peak current limit circuit to become active, voltage transitions on the
output may cause nuisance tripping of the OVP circuit.
Trigger Connections
The BNC trigger connectors on the rear panel let you apply trigger signals to the ac source as well as
generate trigger signals from the ac source. The electrical characteristics of the trigger connectors are
described in appendix A. More information on programming external triggers is found in chapter 4 of the
ac source Programming Guide.
Trigger IN Allows negative-going external trigger signals to trigger the ac source.
Trigger OUT Generates a negative-going pulse when the selected transient output has occurred.
Digital Connections
This connector, which is on the rear panel, is for connecting the fault and the inhibit signals. The fault
(FLT) signal is also referred to as the DFI signal in the front panel and SCPI commands. The inhibit (INH)
signal is also referred to as the RI signal in the front panel and SCPI commands.
The connector accepts wires sizes from AWG 22 to AWG 12. Disconnect the mating plug to make your
wire connections. The electrical characteristics of the digital connectors are described in appendix A. More
information on programming the digital connectors is found in chapter 4 of the ac source Programming
Guide.
NOTE: It is good engineering practice to twist and shield all signal wires to and from the digital
connectors
The following examples show how you can connect the FLT/INH circuits of the ac source.
In example A, the INH input connects to a switch that shorts pin + to pin ⊥ whenever it is necessary to
disable output of the unit. This activates the remote inhibit (RI) circuit, which turns off the ac output. The
front panel Prot annunciator comes on and the RI bit is set in the Questionable Status Event register. To reenable the unit, first open the connection between pins + and ⊥ and then clear the protection circuit. This
can be done either from the front panel or over the HP-IB/RS-232.
27
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