Features of performance
- Frequency range up to 1,000 Hz
- Single-phase and three-phase devices
- Input voltage 280 V and 500 V
- Single-phase power from 500 W to 21,000 W
- Three-phase power from 3 x 1,400 W to 3 x 8,400 W
- Parallel, in star or in delta connectable
- User interface with 4.3" touchscreen
- Operation by mouse
- Operating modes constant current, constant resistance, constant voltage, constant power
- Arbitrary current waveforms
- Uninterrupted change of waveforms
- Synchronization to load input, line or extern
- Variable phase cut from -180° to +180°
- Variable crest factor up to 4
- Automatic amplitude correction
- Variable phase shift in combination with crest factor
- Harmonics up to the 25th order, even and odd
- Variable current protection
- List operation, also with three-phase current
- LAN, USB, RS-232 standard, GPIB optional
- Analog I/O port with real-time signals optional
- Manual on board
DescriptionACL series loads are suitable for DC and AC voltages up to 1,000 Hz. There are single-phase models as well as three-phase loads which combine 3 channels or phases, respectively, in one housing. Ethernet, USB, RS-232, CAN, I/O interface and a system bus for Master-Slave operation are built in as standard, a GPIB interface is available as an option. Programming is done in SCPI.
Operating ModesThe ACL series loads have constant current, constant resistance, constant power and constant voltage modes (CC, CR, CP, CV Mode). In AC operation, the set waveform is applied to the load current, independent of the input voltage. In resistance mode, the current level and waveform depend on the level and waveform of the input voltage. In power and voltage mode, the power or voltage is controlled by software by adjusting the input current.
Input Mode, SynchronizationThe input mode defines the kind of voltage the electronic load expects at the input:
- DC: direct voltage
- AC: alternating voltage within the specified frequency range with synchronization to input voltage, line/mains voltage, external signal
- Adjustable overcurrent protection
- Overpower protection
- Overtemperature protection
- Overvoltage indication
- Undervoltage indication
I/O Port (Option ACL06)All inputs and outputs of the optional I/O port are galvanically isolated from the load input. The control inputs can be operated by 2 ... 24 V. Signals for:
- Analog load setting from 0 ... 5 V or 0 ... 10 V in CC mode
- Operating mode selection
- Input mode (AC, DC)
- Synchronization source (input, line, extern)
- Load activation
- Control source selection (intern, extern)
- Trigger input
- Trigger output
- Synchronization input
- Remote shut-down input
- Analog voltage monitor output 0 ... 10 V
- Analog current monitor output 0 ... 10V
- Analog monitor outputs as proportional AC curve or rms value, selectable
- Programmable digital output
- Status output for load input activation
- Status output for overload
Single and 3-Phase LoadsBesides single-channel AC loads ACLS, the models of the ACLT series have been developed for loading three-phase systems. They combine 3 AC load channels in one housing. The 3 load channels can be used to load 3 different DUTs in AC or DC operation or to test a three-phase system. In the so-called balanced mode, all channels are loaded with the same setpoint and the same waveform. In synchronization mode Line, channel A synchronizes to the mains voltage, channels B and C are each phase-shifted by 120°. To increase the maximum load current, several channels of an ACLT three-phase device or several ACLS single-phase devices can be connected in parallel. Several single-phase devices can be connected to form a Master-Slave system.
User InterfaceIn addition to the load input, which is controlled by a large push-button, and the rotary knob for adjusting the setting value, the devices are operated by intuitive menu navigation via a 4.3" touch display like it is known with smartphones. The most common functions can be accessed via shortcuts. An associated help window is available for each dialog window, explaining the meaning of the respective elements. The help language can be set to German or English.
MouseIf you prefer to operate by mouse, you can use the USB port on the front - the H&H mouse is included.
Manual on BoardThe ACL series user manual is stored in PDF format in the internal device memory. This can be copied to a USB flash drive or, conversely, updated from a USB flash drive if a newer version is available, e.g. after a firmware update with new functions. Thus, the user manual corresponding to the installed firmware doesn't get lost.
- Crest Factor, Phase Cut, Phase shift
- Arbitrary Waveforms
Load Profile (LIST Function)In all operating modes, the ACL load can emulate load profiles by means of the LIST function. Up to 300 setpoints of variable duration with associated ramp times are possible. In AC mode, the LIST function serves as a load profile of RMS values with the active waveform. Sampling times can be defined separately for each list section. Voltage and current are measured synchronously and stored with a time stamp.
Rectangular FunctionLikewise for all operating modes, the rectangular function offers a simple variant for changing between 2 setting values with adjustable durations. In AC mode, the rectangle function serves as a load profile of 2 rms values with the active waveform.
DAQ Acquisition (DAQ)The electronic load can also store synchronous data records of voltage and current with time stamp in a defined interval, independent of the LIST function. Up to 40,000 data records are stored in a ring buffer. Once recording is complete, the data is read out via a data interface or transferred to a USB flash drive.
Static Data LoggingDuring slow processes, the electronic load can store voltage and current with timestamps directly on a USB flash drive in local mode. Sampling intervals are in the range of seconds.
Trigger ModelIn remote operation via a data interface, several functions can be activated by a configurable trigger event:
- Activation/deactivation of list execution
- Activation/deactivation of data acquisition
- Activation/deactivation of load input
- Setting of all triggered setting values of all operating modes
Save SettingsIn order to quickly reconstruct frequently recurring test tasks, the settings active in the electronic load can be stored non-volatile so that they can be reloaded later on. 9 memory positions are available. The ACL load can optionally set the reset state when switching on, the last active settings at power-off or memory positions 1 to 9.
Watchdog FunctionTo protect the DUT from communication problems, the electronic load in digital remote control mode has a watchdog function that switches off the load input if the previously programmed watchdog delay time expires without the watchdog being reset. The watchdog delay time is set by SCPI command, another command activates the watchdog. When the watchdog is active, a control program must ensure that the command to reset the watchdog is periodically sent to the electronic load.
Display of MeasurementsDepending on the focus on the display, more or less measured values are shown per channel. A single-phase ACLS device displays the following measured values in the main display: RMS value voltage, RMS value current, resistance, active power, apparent power, reactive power, frequency, power factor, crest factor. If all channels ABC of a multi-channel or three-phase device are focused, the effective value of the voltage and the effective value of the current are displayed for each channel. All these measured variables can be queried via one of the data interfaces using a SCPI command.
Waveform DisplayThe last measured period of current and voltage is measured with 360 points and displayed in the Measured Waveform dialog.
Yt GraphThe Yt-Graph shows the time course of the RMS value of voltage, current and/or power of the focused channel.
CalibrationA free Factory Calibration Certificate (FCC) is supplied with the devices. The calibration process is subject to supervision in accordance with DIN EN ISO 9001. The calibration certificate documents the traceability to national standards to illustrate the physical device in accordance with the international System of Units (SI). Within the warranty period we calibrate a second time for free.
DocumentationWe supply a user manual as pdf file (also saved in the electronic load) and printed General Safety Instructions, each in German and English.
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