Atec 3091LD User Manual

California Instruments 3091LD

3000–12000 VA

3000VA Programmable AC Loads

• Multi-mode AC Electronic Load
Flexible solution for a wide range of AC power test
applications

• 3000 Watt Power Dissipation
Master / Auxiliary congurations for higher power
and multi phase applications

• 50 to 350 V, 45 Hz to 440 Hz
Commercial, Military and Avionics applications

• Programmable Crest & Power Factor
Test AC power products for real-world conditions

• Built-in Measurements
Eliminates the need for additional test equipment
in bench or ATE applications

• Remote Control
IEEE-488 and RS232C Interface for automated
test applications

AC Loads

The 3091LD is designed to provide precisely
controlled, non-linear loads for testing AC power
generation equipment such as UPS’s and AC
sources. In addition, any active or passive current
carrying devices such as switches, circuit breakers,
fuses, connectors and power semiconductors
can be tested. Traditionally, many of these
products are tested using resistive load banks.
This approach does not simulate real-world
conditions such as switching DC/AC converters
found in many AC powered products. This type
of conventional testing does not fully exercise
the equipment under test (EUT) under worst case
operating conditions. High peak currents and low
power factor loads can signicantly impact the
operating characteristics of a UPS or AC power
product. The 3091LD AC Load can simulate
high crest factor and variable power factor load
conditions. This provides an effective method of
testing AC products against real-world conditions
and can signicantly increase product reliability.
Unless properly exercised, product defects may go
undetected until a unit is used at a customer site,
resulting in costly eld returns.

Front Panel Control

The AC load can be operated from an easy to
use, menu driven front panel. Product tests
can be performed quickly in an R&D setting by
punching up specic load conditions on the front
panel and reading the measurement screen of
the 3091LD. This fast interactive front panel
control mode can be used during a product’s
early development cycle to isolate potential
performance problems before the product leaves
the engineering lab.

Automated Testing

The 3091LD can be deployed in ATE test stations
using either IEEE-488 or RS232C remote control.
The industry standard SCPI (Standard Commands
for Programmable Instrumentation) protocol
is used and instrument drivers are available to
ease test software development. The built-in
metering functions of the 3091LD AC load can
be used to eliminate the need for additional test
equipment such as meters, power analyzers and
oscilloscopes.

This and the reduced size of the 3091LD
compared to passive load banks, represents a
savings in both cost and rack space.

Power Levels

Each 3091LD is capable of dissipating 3000 W
of single phase AC power. For higher power
or three phase applications, a 3091LD master
unit can be combined with one or more auxiliary
3091 units. The master 3091LD unit provides the
required consolidated measurements so the test
system controller - or the operator - need only
interface to the master unit, regardless of the
specic conguration. Single, split or three phase
congurations can be software congured from
the master 3091LD when combined with 3091
slave units.

User Control

All AC load modes are easily set from the front
panel using a menu-driven user interface.
The large LCD screen is used to display setup
information as well as measurement data.
Measurements include volt RMS, volt peak,
current RMS, current peak, crest factor, true
power, apparent power, power factor and
frequency. Both voltage and current waveforms
at the load input terminals can be digitized
and displayed on the front panel graphical
LCD. This allows EUT output behavior to be

50–350 VRMS

30 ARMS

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Programmable Power

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San Diego, CA 92121-2267
USA

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3091LD

analyzed quickly without the need to hook up
additional test equipment. A Windows graphical
user interface (GUI) is provided to expand the
measurement and display capabilities of the
3091LD. The GUI can be used to save and print
test results for report purposes.

Crest Factor and Power Factor control

When operating in constant current or constant
power mode, the 3091LD supports crest factor
control by narrowing the conduction angle of
the current waveform in order to match the
requested crest factor. Thus, the peak current is
increased while retaining the RMS current level.
While the apparent power remains constant, the
true power decreases. This results in a reduced
true power factor. Consequently, as crest factor
is increased, the true power factor automatically
decreases. The load further controls power
factor by shifting the current with respect to
the input voltage (displacement power factor).
Both leading and lagging power factor control
is available. A phase shift of the current is only
possible if the crest factor is higher than 1.414.
Thus, crest factor and power factor control ranges
are coupled as shown in the graph to the right.

Front Panel

The large LCD screen is used to display setup
information as well as measurement data.

Measurements include volt RMS, volt peak,
current RMS, current peak, crest factor, true
power, apparent power, power factor and
frequency. Both voltage and current waveforms
at the load input terminals can be digitized
and displayed on the front panel graphical
LCD. This allows EUT output behavior to be
analyzed quickly without the need to hook up
additional test equipment. A Windows graphical
user interface (GUI) is provided to expand the
measurement and display capabilities of the
3091LD. The ICS can be used to save and print
test results for report purposes.

Power & Crest Factor Control Range

Load Power Rating curve for 3091LD

The 3091LD can be used to emulate a wide variety of
AC load conditions to support real-world testing and
evaluation of UPS and AC source products. Specically,
the following modes can be selected:

Mode Description

Constant
Power

Constant
Resistance

Constant
Current

Constant
Voltage

Short
circuit

CP This mode effectively emulates constant

power loads such as switching power
supplies

CR Emulates a conventional resistive load or

power resistor. A programmable range
from 2.5 Ohms to 1000 Ohms covers a
wide range of applications. This mode
can be used to replace conventional
resistive load banks.

CC Provides a constant current load. This

mode may be used to simulate both linear
(resistive) and non-linear (active loads for
voltage regulation testing.

CV This mode emulates a shunt regulator

load and may be used to test current
source products.

SC Test the short circuit protection mode of

the EUT by providing a short condition.
The 3001LD can handle surge currents
of up to 300 Amps for up to 50 msec and
sustained currents of 30 Amps in this
mode of operation. The low voltage
cut-off of the load can be programmed
from 50 Volts up.

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3091LD : Specications

3000–12000 VA

Ratings

Power 3000 W @ 0-37° C; 2400 W @ 38-50° C

Current 30 ARMS

Voltage 50 to 350 VRMS

Frequency 45 to 440 Hz

Max. Peak Power 13 kW (up to 20% duty cycle)

Max. Peak/Surge Current 90 APEAK Surge: 300 APEAK for 50 ms

Max. Peak Voltage 500 VPEAK

Operating Modes

Constant Current Range: 0 to 30 ARMS; Accuracy: 0.2 % of full scale; Resolution: 0.05 % of full scale; Min. Set Current: Voltage / Maximum Set Resistance

Constant Voltage Range: 50 to 350 VRMS; Accuracy: 0.2 % of full scale; Resolution: 0.05 % of full scale

Constant Resistance Range: 2.5 to 100 Ohms, 100 to 1000 Ohms; Accuracy: 1% FS, 5% FS; Resolution: 0.05 % FS; Max. Set Resistance: 1 / (Freq.*1.3e-5)

Constant Power Range: 3000 W @ 0-37° C,2400 W @ 38-50° C; Accuracy: 0.5% of full scale; Resolution: 0.1% of full scale

Crest Factor Range: 1.4142 to 4.0, limited to 90 Apeak; Accuracy: 1 % of full scale; Resolution: 0.1 % of full scale

Power Factor Range: 0 to 1 lead or lag limited by Crest factor settings; Accuracy: 1 % of full scale; Resolution: 0.1 % of full scale

Shourt Circuit Mode Max. Surge current: 300 APEAK, up to 50 msec; Max. Cont. current: 30 ARMS; Max. Voltage drop: 2.5 VRMS

Measurements

Frequency Range: 45 to 440 Hz; Accuracy: 0.1% FS; Resolution: 0.05% FS

Voltage Range: 50 to 350 VRMS; Accuracy: 0.1% FS; Resolution: 0.05% FS

Peak Voltage Range: 50 to 500 V; Accuracy: 0.5% FS; Resolution: 0.1% FS

Current Range: 0 to 30 ARMS; Accuracy: 0.2% FS; Resolution: 0.1% FS

Peak Current Range: 0 to 90A; Accuracy: 0.5% FS; Resolution: 0.1% FS

Crest Factor Range: 1,4142 to 4.0; Accuracy: 0.5% FS; Resolution: 0.1% FS

Apparent Power Range: 0 to 3000 VA; Accuracy: 0.5% FS; Resolution: 0.1% FS

True Power Range:0 to 3000 W; Accuracy: 0.5% FS; Resolution: 0.1% FS

Peak Power Range: 0 to 45,000 W; Accuracy: 1% FS; Resolution: 0.1% FS

Reactive Power Range: 0 to 3000 VA; Accuracy: 0.5% FS; Resolution: 0.1% FS

Power Factor Range: 0 to 1; Accuracy: 0.5% FS; Resolution: 0.1% FS

Resistance Range: 2.5 to 100 Ohms,100 to 1000 Ohms; Accuracy: 1% FS, 5% FS; Resolution: 0.05% FS

Protection

Over Current Limited by input - Circuit Breaker and Set Maximum Current Limit in software.

Over Voltage Output protected for voltage transients over 500 V in hardware.

Over Power Power limited at maximum average and peak rated power in hardware. Limited to Set Maximum Power Limit in software.

Over Temperature Monitors heat sink temperature.

Mechanical Specications

Dimensions H: 8.75” (222 mm), W: 16.88” (429 mm), D: 25“ (635 mm)

Weight 74 lbs / 34 Kg.

Remote Sensing Max. 2V drop between sense and load lines

Isolation 1000 V between input and chassis ground

Audible Noise (@1meter) Audible Noise (@ 1meter): Low power: 49.0 dBA; Full power: 69.5 dBA

Control Power Input 115 Vac or 230 Vac (model -230) ± 10%, 47 to 63Hz

Operating Temperature 3000 W @ 0-37° C, 2400 W @ 39-50° C

Interfaces

GPIB Standard

Note: Specications are subject to change without notice. Specications are warranted over an ambient temperature range of 25°± 5° C. Unless otherwise noted, specications are per phase for a sinewave with a resistive

load and apply after a 30 minute warm-up period. For three phase congurations, all specications are for L-N. Phase angle specications are valid under balanced load conditions only.

© 2009 AMETEK Programmable Power All rights reserved. AMETEK Programmable Power is the trademark of AMETEK Inc., registered in the U.S. and other countries. Elgar, Sorensen, California Instruments, and Power Ten are

trademarks of AMETEK Inc., registered in the U.S.

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3091LD

Ordering Examples:

1 x 3091LD-RMS
2 x 3091-RMS

Three unit, 9000 Watt system with rack slides.
3091LD-RMS-230

Remote Control

IEEE-488.2 GPIB talker, listener
Subset: AH1, C0, DC1, DT1, L3,
PP0, RL2, SH1, SR1, T6
Language: SCPI
RS232C
Baud rates: 9600, 19200, 38400
Handshake: RTS/CTS
Format: 8,n,1
Language: SCPI

Options:

-230 AC Line input 230 V L-N. Must be
specied at the time of origninal
order.

-BTM Bench Top Model. No handles
and rack mount ears. Must be
specied at the time of origninal
order.

-MSK Master/Auxiliary Cable Kit
Required to use 3091LD as
auxiliary unit.

-RMS Rack Mount Slides

C1-CS Cabinet. Add prex “C” to model
number to order a rack mounted
system.

Note: For rack mounting, option -RMS is
recommended.

Single table top unit rated for 230 V L-N input.

Supplied with:

• Instruction / Programming Manual

• Windows™ Graphical User Interface

• Load Input Connector

• RS232C Serial Cable

AC and DC Sources

Expand your AC test systems with line input
immunity testing of voltage sags, surges, swells
and drop-outs using the California Instruments
iX Series of programmable AC and DC power
sources. The iX Series is an ideal companion
product to the LD Series AC loads, providing
3000 VA to 30 kVA of AC power.

Features include arbitrary waveforms, transient
generation and extensive measurements.

Congurations

Higher power AC loads or multi phase AC loads
can be created by combining one 3091LD master
with one or more 3091 auxiliary units in a rack
system. Contact factory for system conguration
information.

Standard controller versions with single
voltage range

Model Output Input Voltage

3091LD 3000 W AC Load 115V

3091 3000 W AC Load Auxiliary 115V

3091LD Dimensions

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