Agilent Technologies 6813B, 6812B, 6811B User Manual

User’s Guide

AC Power Solutions

Agilent Models 6811B, 6812B, and 6813B

For instruments with Serial Numbers:

Agilent 6811B: US38390101-up Agilent 6812B: US38390101-up Agilent 6813B: US38390101-up

Agilent Part No. 5962-0829 Printed in U.S.A.

Microfiche No 5962-0830 December, 1998

Update April 2000

Warranty Information

CERTIFICATION

Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory. Agilent Technologies 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 Agilent Technologies hardware product is warranted against defects in material and workmanship for a period of three years from date of delivery. Agilent Technologies software and firmware products, which are designated by Agilent Technologies 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 Agilent Technologies will, at its option, either repair or replace products which prove to be defective. Agilent Technologies 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 Agilent Technologies. Customer shall prepay shipping charges by (and shall pay all duty and taxes) for products returned to Agilent Technologies for warranty service. Except for products returned to Customer from another country, Agilent Technologies shall pay for return of products to Customer.

Warranty services outside the country of initial purchase are included in Agilent Technologies product price, only if Customer pays Agilent Technologies international prices (defined as destination local currency price, or U.S. or Geneva Export price).

If Agilent Technologies 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 Agilent Technologies.

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. AGILENT TECHNOLOGIES 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. AGILENT TECHNOLOGIES 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

Agilent Technologies Sales and Service office for further information on Agilent Technologies’ full line of Support Programs.

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 safet standards of design, manufacture, and intended use of the instrument. Agilent Technologies assumes no liabilit

or 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.

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

Terminal for Line conductor on permanently installed equipment

WARNING

Caution

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 si 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 si 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.

n denotes a hazard. It calls attention to a procedure, practice, or the like,

n denotes a hazard. It calls attention to an operating procedure, or the like,

Declaration Page

Manufacturer’s Name: Agilent Technologies, Inc. Manufacturer’s Address: 140 Green Pond Road

declares that the Product

Product Name: a) AC Power Source/Analyzer

Model Number(s): a) Agilent 6811B, 6813B, 6812B, 6811A, 6812A, 6813A

conforms to the following Product Specifications:

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) Agilent 6841A, 6842A

Safety: IEC 1010-1:1990+A1(1992) / EN 61010-1:1993

EMC: CISPR 11:1990 / EN 55011:1991 - Group 1 Class A

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 Agilent Technologies Sales and Service Office or Agilent Technologies GmbH, Department TRE, Herrenberger Strasse 130, D-71034 Boeblingen (FAX:+49-7031-14-3143)

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

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 Agilent Technologies. The information contained in this document is subject to change without notice.

Edition 2 _________February, 1997 Edition 3 _________March, 1998 Edition 4 _________December 1998 Update _________April 2000

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 17 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

GPIB Connector 28 RS-232 Interface 28

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 47 3 - Setting the DC Offset 48 4 - Setting a Protection Feature 48 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 GPIB 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 53

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

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 GPIB 76

Agilent 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 Agilent 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

General Information

Document Orientation

This manual describes the operation of the Agilent 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 GPIB 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

- GPIB 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

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

Agilent 6811B Agilent 6811A AC Power Source/Analyzer Agilent 6812B Agilent 6812A AC Power Source/Analyzer

Agilent 6813B Agilent 6813A AC Power Source/Analyzer

also applies to the following earlier

models:

Agilent 6841A Harmonic/Flicker Test System

in normal mode

Agilent 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 (Agilent p/n 5062-3977) 1CP All Rack mount kit with handles (Agilent p/n 5062-3983) 100 Agilent 6811B/6812B 87-106 Vac, 48-63 Hz (Japan only) 200 Agilent 6813B 174-106 Vac, 48-63 Hz (Japan only) 230 Agilent 6811B/6812B 191-254 Vac, 48-63 Hz 831 Agilent 6812B/6813B 12 AWG, 200 to 240 Vac, unterminated 832 Agilent 6813B 4-mm2 wire size, unterminated 833 Agilent 6812B 1.5-mm2 wire size, 200 to 240 Vac, unterminated 834 Agilent 6812B 10 AWG, 100 to 120 Vac, unterminated 841 Agilent 6812B/6813B Line cord with NEMA 6-20P; 20A, 250 V plug 842 Agilent 6813B Line cord with IEC 309; 32A, 220 V plug 844 Agilent 6813B Line cord with NEMA 6-30P; 30A, 250 V locking plug 845 Agilent 6812B Line cord with IEC 309; 16 A, 220 V plug 846 Agilent 6812B Line cord with NEMA L5-30P; 30 A, 120 V plug 847 Agilent 6812B Line cord with CEE 7/7; 16 A, 220 V plug

848 Agilent 6812B Line cord with BS 546; 15 A, 240 V plug Support rails (

Agilent 6811B units are shipped with the correct line cord for the destination country.

Agilent p/n 1494-0059) are required when rack mounting units with options 1CM and 1CP.

The following table lists some common user-replaceable parts:

Table 1-2. Operator Replaceable Parts

Item Agilent 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 Agilent 6812B (30 AM) 2110-0910 Line fuse for Agilent 6813B (25 AM) 2110-0849 Line fuse for Agilent 6811B (20 AM) 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

AM P LIF IE R

shunt

MEASUREMENT

BLOCK

POWERMETER

FFT ANALYZER

Figure 1-1. AC Source Functional Elements

1 - General Information

The following model ac power sources are described in this User’s Guide:

Model Description

Agilent 6811B 0-300 V rms; 375 VA (425 V peak; 40 A peak) Agilent 6812B 0-300 V rms; 750 VA (425 V peak; 40 A peak) Agilent 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 GPIB 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 GPIB 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.

General Information - 1

Remotely programming is accomplished from either the GPIB bus or from an RS-232 serial port. GPIB 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

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)

Vrms

1.25A (6811B)

2.5A (6812B)

5.8A (6813B)

AC CHARACTERISTIC

(45Hz - 1kHz sinewave)

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)

DC CHARACTERISTIC

424 V

Vdc

0.67A (6811B) 2.5A (6811B)

1.35A (6812B)

3.17A (6813B)

-424 V

-Vdc

285W (6811B)

575W (6812B) 1350W (6813B)

5A (6812B)

10A (6813B)

Idc

Figure 1-2. Steady-state Output Characteristic (in real-time mode)

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 ( 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.

Agilent 6811B/6812B) or 80A (Agilent 6813B), the unit

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

Agilent Agilent 6811B equivalent dc voltage when current is flowing

6813B Agilent 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

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

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

setting

eak

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

Figure 1-3. Peak Inrush Current Example

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.

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.)

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 immediately. The list of information is printed in the front of this guide.

Agilent Sales and Support Offices is at the back of this guide. Warranty

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.

Agilent Sales and Support Office

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 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.

Agilent Sales and Support Office (refer to the

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.

2 - Installation

Location

Refer to the Safety Summary page at the beginning of this manual for safety-related information about environmental conditions.

CAUTION: Agilent 6811B/6812B units weigh 28.2 kg (62 lbs).

Agilent 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. Agilent 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"

Figure 2-1. Outline Diagram

Installation - 2

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.

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.

2 - Installation

L1 L2(N)

1. GROUND CONNECTION (GRN/YEL OR GRN)

2. LINE CONNECTION (BRO WN O R B LACK)

3. NEUTRAL CONNECTION (BLUE OR WHITE)

4. POWER CORD

5. CONNECTOR NUT

6. RUBBER BOO T

7. POWER SAFETY CO V ER

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

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.

Resistance

(Ω/m)

Constant

NOTES:

AWG No. Ampacity

Temp. (°C) Temp. (°C)

Resistance

(Ω/m)

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:

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 opencircuited.

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

LOAD

COM COM

Figure 2-5. Remote Sense Connections

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 re-enable 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 GPIB/RS-232.

2 - Installation

In example B, the FLT output of one unit is connected to the INH input of another unit. A fault condition in one of the units will disable all of them without intervention either by the controller or external circuitry. The controller can be made aware of the fault via a service request (SRQ) generated by the Questionable Status summary bit.

FLT INH

NOTE: Connectors

are removable

FLT INH

INH Common

Switch

(Normally

Open)

INH Input

A) INH Example with One Unit

. . . .

INH Input

FLT Output

B) FLT Example with Multiple Units

. . . .

Figure 2-6. FLT/INH Examples

Controller Connections

The ac source connects to a controller either through a GPIB or an RS-232 connector.

GPIB Connector

Each ac source has its own GPIB bus address. AC sources may be connected to the bus in series configuration, star configuration, or a combination of the two. You may connect from 1 to 15 ac sources to a controller GPIB interface.

NOTE: The ac source is shipped from the factory with its GPIB address set to 5. This address

can be changed as described in Chapter 4 of this guide.

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